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[3 Easy Tips] How to Fix your LED Spectrum for Flowering Plants

Welcome! My name is Dan, and I’m excited you’re here.

I study the science of photobiology and let me tell you, not many grow lights out there are giving your plants the colors they need… or want…

I can’t wait to share with you secrets about how plants are affected by color, how most grow lights on the market give out the wrong color, and what you can do about it without replacing your entire grow light system!

Today, we will fix the spectrum in your garden. This means happier plants and bigger yields await…

Today is a good day to be you!

Use these tips to unlock better growth in your garden with a few simple steps — all under $100 and one is even free! You’ve taken a solid step forward to fix your LED system’s spectrum. Your plants will reward you!

By correcting the spectrum, you allow the plants to grow bigger and better. Traditional LED lights starve your plants of required colors and wavelengths they expect in nature.

Sometimes the colors that common LED grow lights give out are all out of whack and your plants just “deal with it” … but aren’t growing to their full potential.

Just because your plants are staying alive and getting bigger… doesn’t mean they are thriving! You may have bought these lights online, and of course they work, but have you experienced growth greatness? Growing alone is hard enough as it is…why should we have to worry about light when all we are doing is trying to save power with LED?

The good news is, most of these fixes require only a small investment, and one is even free!

After you read this, join in the conversation below and ask questions if you have any. Feel free to post what grow light you have if you’re looking for specific advice.

I’m excited for you and your garden! Are you ready? Let’s go.

All LED Owners – Temperature & Airflow Check!

Even though your LEDs might run nice and cool… you do need to keep those temperatures up in your grow tent to get maximum yields.

The High Pressure Sodium bulbs give out a spike of heat that plants actually love, so you’ll actually need to run your grow environment hotter than what you normally would with high pressure sodium.

This is good because letting your room get hotter means you need to use less energy cooling it!

Aim for eighty degrees, but 78-82 degrees is the sweet spot.

Because LED’s run nice and cool, it’s also important to get extra airflow over your plants, they breathe less without exposure to high heat – so be sure you have at least one clip fan blowing over the tops of your plants.

Attn: All Purple LED Light Owners With “Veg” And “Flower” Switches or Color Dials

Does your LED grow light have a “Veg” or “Flower” switch? If so, stop turning off the “Flower” or “Bloom” switch for veg …. unless you’re hoping to preserve a small plant in a nursery setting.

Depriving your plants of red light and dumping them with blue light will stunt their growth. Just check out what happens to lettuce below in a scientific study when blue light % increased…

The reaction of lettuce when exposed to certain percentages of blue and green light.

They found that blue light actually stunted growth by reducing leaf size while also diminishing the rate of photosynthesis. Crazy right?

What’s more, blue light is the color that causes the greatest stress and light burn.

If possible, run your LED light with both “Veg” and “Flower” turned on. Back off the light to reduce the intensity, and your plants will thank you in return with vigorous growth!

If you have dimmable dials on your LEDs, during veg try keeping blue lower than what you normally would and observe the results… Every photobiology study out there recommends Blue light to be lower than 30% for optimal results during vegetative growth for flowering plants. If you could get that down to 15% it would be even better.

If you have Red/Blue/White switches, try your results with just “Red” and “White” turned on. “White” actually has a lot of blue light, just enough to give what plants need so that they don’t “stretch”.

Take a peek at your spectrum (more on that below) and use the information above to try to reduce the amount of blue, especially in your vegetative growth cycle because it will change how your plant grows and how big and fast the leaves expand.

Bigger leaves…faster growth…more harvest…

You will be blown away at the results.

During early flowering, when the leaf growth is slowing, turn on all of the channels at max power and let er’ rip.

Trust me…. I know it sounds like one of those statements on the back of a Microwavable Popcorn bag that says “Do not use your Microwave’s ‘Popcorn’ button” … but seriously… don’t use your grow light’s veg and bloom switches as they are intended. You will end up with smaller yields.

Drop me a note below with a comment and click “Submit” with any questions and I will respond and help you “fix” your grow light’s settings!

All Purple LED Light Owners

We’re trying to do two things with grow lights that have mostly red and blue in their spectrum…

  1. Blue Light Correction – This is the most important step to fix if your grow light has primarily blue light. If you own a “ViparSpectra” this is definitely a step to take for you (this light is really meant for aquariums). Try to find the manufacturer’s web page. You’re looking for a spectrum graph. You can also count the number of red and blue LEDs to get an idea. If there is an equal or higher amount of BLUE than RED, you’re going to want to fix that for all stages of growth. We want blue light to be UNDER 30% and OVER 10% of the total spectrum.
  2. Full Spectrum Correction – Our goal here is to nourish plants with some full spectrum light (green/yellow) to help them thrive with more light information. In addition, that should help your eyes out! Adding white light will assist you in caring for your plants so you can see them in natural color. A win-win!

My recommendation is to add a 50W Warm White LED Flood Light to your garden. It’s about $35 with CREE LEDs, so you cannot go wrong. Above all, it will snap most blue-heavy or red/blue spectrums into balance. These flood lights are great to have around and I use them myself! They are fantastic to use on their own for young seedlings and can easily be positioned into tight areas of your grow space.

Plus, the more light sources you have in your grow space, the better light penetration and spread you will have. This means a bigger usable grow area and more growth deeper in your canopy. What’s more, you can experiment with positioning these lights to the side and getting more angles of light sent towards your plant that will create bushier growth… Talk about an upgrade!

To start, find out how much your grow light pulls from the wall, not the advertised wattage. For example, the Viparspectra 300W, while advertised at 300W actually pulls 136 Watts from the wall. Be sure to find the right number. You’ll have to search for it!

You’ll want to take Total Watts / 2 and shoot for that in your supplemental lighting. So if Total Watts is 136, half that is about 70W. We want about 70W of supplementary light.

If you have a ViparSpectra 300W, we’d want 1 or 2 50W Warm White LED Flood Lights for our light supplementation project.

What are you waiting for? At such a low price to get started with just one, you can’t go wrong.

White And Purple LED Light Owners (The Best Solution)

Buy a low wattage HPS Light! You will not regret it. I work with production-level growers and if they are growing with LED, many of them are also supplementing with HPS bulbs.

The reason? It works.

I know it seems counter-intuitive, but you will save MORE energy by getting GREATER YIELDS with the kind of yellow, red, and infra-red light that the HPS puts out. Simply providing just a little bit of the colors that are missing in white or purple LED systems will unleash a huge amount of growth in your garden.

The quality and quantity of your harvest will increase for just a small investment… It will snap your purple and white LEDs and turn them into a monster grow setup.

You will want to supplement your grow ideally with a 1:1 ratio of LED to HPS power. Half HPS power is great as well.

For $70 and only 150 Watts of power, how can you go wrong?

What about Next-Gen LED Technology?

I never thought you’d ask! If you’re waiting for the next big thing, you’ve come to the right place.

Now that you’re here and learning, check out how plants use light and watch the video article to learn even more!

Keep growing green my friends, and don’t forget to leave a comment below!

162 thoughts on “ [3 Easy Tips] How to Fix your LED Spectrum for Flowering Plants ”

I have 4 mars hydro 1200 watt lights are these good enough on there own if not what should i do thanks

Hi Dan,
Thanks for the great article. I think it’s what I’ve been looking for. I bought a Mars Hydro LED and it is driving me crazy, the tsw-2000. I’m trying to grow autos with it and I think it must have too much blue because I keep getting squat plants with too short internal spacing. I just ordered a 50W flood with 3.000K light, like you spoke of. What I don’t understand is how a blue light spectrum addition can correct a ‘blue heavy’ light? It seems like I would want a 6.000K light. Maybe HPS is the only way? Can you advise ?

This answers a few questions I’m running 3 Ismile 1000 watt led that=105. full spectrum veg & bloom my ladies are in first stage of flower problem is they have outgrown the tent I’ve since bent & tied down branches and took them out of the tent they seem to be growing or making flowers really slow any advice.

I’m a commercial Grower based in Oklahoma and I’m using the Electric Sky 300’s as my primary lighting source in many of my rooms. I have a couple that supplement with HPS – Holy Smokes; you weren’t kidding about this upgrade. I am curious about a singular detail though.

I’m not the original Grower for this operation, the third, in fact. I have noticed a major spectrum difference between all of these systems. There seem to be two, possibly three different light spectrums present here. I see some lights are warmer than others; there may be a handful that are between the two, as well. Every light carries the same model number so I cannot determine if this has been an intentional spectrum shift, or if it’s simply a result of batches of LEDs from your suppliers. Care to shed some.. light!?

Thanks for any information you can offer.

Oh, by the way, the number and layout of red chips seems to be the same across the board. The only change looks to be the white chips; half are cool temp, the other half warm. Every light has the same white color temp, individually, so I could easily re-hang the cool systems in my veg rooms, warm in bloom. Thanks again.

I have a ppf 800 1 switch high n low which do I use 2 grow n which 2 flower

When using a light like that, it is best to just leave both switches on.

Hi Dan,
Great page with lots of good advice.
I’ve just changed from HPS to LED with red white and blue dimmers. It also has UV and IR.
I’ve never used led before and really need some advise if you don’t mind.
I grow from seed for 4-5 weeks then move them to the main grow area. What combination of red/white/blue do I use from this point until harvest?

Just wondering if a far red initiator puck would be of any good when using the ES300 v2 or v3. Some use it to assist with putting the plants to sleep is my understanding and it supposedly assists in initiating the flower cycle. Dan mentions this in his newest video with Mr. Grow it. I understand the ES300’s are much different than other lights in terms of spectrum and effect and before I purchased them I had also looked at these Far Red pucks or diodes. They would be easy to DIY and there are now a couple companies selling them.

Orig Glue Auto. I have a MZVUL…100w 186 LED 3 Modes, Full Spectrum Grow Bulb $25 Amazon. I Put my Seedling under Blue light From CFL and it Immedietly Drooped …..Put CFL back on and MAGIC…Back to Perkyness. What can i do to Fix what I have? My Light will Not let me Use 2 Spectrums of Light….1 or the Other? Blue Veg or Red Bloom Buttons? What do I do? I am going with CFL until the Flowering Starts and Put in the led and Go to Boom?? Yes /No Thank you Dan

I liked what I read and I am glad to have your opinion. I currently have a spider farmer 1000. Should I turn it down to vegetate at run it and 100% for flower? Is it the right light spectrum? and if not how do I change it.

Hey James, the spider farmer can be good budget grow light. However we’ve found that our light fills in a lot of the spectrum their light is missing for improved quality and yields!

Hi, I’m fairly new to this, after just using hps bulbs, I won’t to try leds, what would be the best all rou nd lighy to purchase, for a small I door garden, approximately 3 plants, do all leds have veg to bloom switches?, thanks and appreciate any help given, yours, ken

Thank you for taking questions. My light is an Apelila 3000w / 576 LEDs / 320w power draw/ 372 full spectrum purple (25% blue) / 8 lime / 182 purple (2.5% blue) / 8 UVA. -Blue 12% – Green/yellow 20% -Red 57% -FRed 8% on Amazon for $136. I have a 3’x3’x6′ tent. I would like to add some cheap additional lighting, would adding 1 – 2 50 – 75w soft white LEDs throw my balance off to much.

I am growing vegetables. My grow light has a veg switch (blue lights), bloom switch (red lights), or both switches on creating a purple light. What light color(s) should I use?

600w “blurple” LED, 5 weeks into flower. I’ve been running both switches to this point. I’m considering running just the deep red Bloom switch for the first hour of light and the last two hours each day. Then full spectrum for the other 9 hours. This is with the idea of transitioning to just running the bloom switch for the last week prior to harvest. Does this sound like a good idea?

Hi! I am using norlma warm light leds, I was wondering, how do I know how much light do I need?

Greetings from Mexico

I have a viparspectra va1000 dimmable, my
plants are 10 days old, still babies, but I’m having a big stretching problem, I followed the guide and I have them to 50% bloom and 75% veg, they’re growing well but they’re stretching a lot. Should I move the light closer? atm they’re about 13-16 inches away from the canopy and they’re still in the humidity box. Should I open the container?

I am having some trouble. I have a 600w viparspectra WITHOUT bloom switch, which from what you wrote, is pretty unnecessary anyway. There is one plant and it appears to be getting light burn when I lower it the light. To have it on 100% intensity for bloom, I have actually had to raise the light and am already on a 12/12 schedule hoping to flower. Should I just keep gradually lowering while also turning down intensity? Should I be supplementing with a red light? Help. I am a beginner.

First time grower.
1000 watt LED
Pushing plants 12 /12 hrs for hair phase. Should I keep my VEG/ BLLOM lights on or just use my BLOOM lights?
photo plants / Sog style

Turn them both on! =)

Hi, I would like to ask if its ok to use cfls for supplemental light when using led? If so, any tips

Hi Lilman yes if you have CFLs around the house the more the merrier, but CFL need to be close to the plant, so perhaps place them on the edges. Would not go out of my way to purchase these for grow lightning, however

I have a Mars Hydro TS 3000w LED equivalent to 800w-1000w HPS, two 1500w Carambola red bloom LED’s I’m guessing run a couple hundred watts a piece and a 40w white led shop lights running vertical for side lighting. My question is with the Mars Hydro led. It has a dial to turn the intensity up and down. With it all the way up it is real bright and puts off a lot of white light and heat. Should I dial it down and lower the lights with this? Some times I afraid I’m not giving enough light when I actually could be giving to much. I’m not sure because my second grow is lagging and I think it’s because summer is here and the tent is warmer.

Hello! I’m using 2 450 watt viparspectra and one 300 in the middle. Currently I have two plants in a 2x4x5 tent. Right now they are in their 6th week of flower. The issue I’m having is the temp goes to around 85F. I added a air duct for cooling from my ac vent but doesn’t seem to help. Should I keep the 450s on bloom only and use the 300 on max to keep the temp down? Thanks!

Hi Aubry 85 degrees is barely OK for LED. You might want to try getting a better airflow situation for your tent, and reduce the temperature of the room itself for the cooling. As long as your plants are happy, should be good to go!

Hey! You’re super cute. Running in to an issue with the heat in my tent with both veg and bloom switches on. I have a 4×2 tent and am currently running an advertised 2000w and 1200w led. Thoughts?

Hi Brian! Make sure you have adequate airflow. Go extra and get a fast fan and that will clear out your grow tent!

hi mr greensunshine I’ve got a 2-600w viparspectra with veg and bloom switches, would you advise to keep switch off veg switch in veg as, ive added 200watt off warmwhite floodlights .and when in flower turn on veg switch ,i was running metal halide 400w but the temp was to hot ,

Yes that is great!

Thanks for these tips.
I’m working on a blooming flower video only.
which color do you recommend for speeding up this part?
The flower come out of a fridge every morning and I’m trying to get them open in 2/3 day time if possible.
Do I still need a bit of Blue, or I should focus on Yellow and red only?

Hello Mr greensunshine,

I just bough a Growstar S600 ( months ) and many little flood light to help the blurple light to add more coverage and penetration also add more red with a 2700/3000k temps flood light .

I am very happy to discover that I was not wrong with the blue spectrum.

I already got a Par meter and I am building my spectrometer to pin-point the right amount of blue to my setup…

My setup is for my seedling of citrus plant , it’s hard to found some specific data in regard of the culture of citrus like Par level quantity , do you have any suggestion where I can find that kind of info ….not the number which will great, but place like university or site that hold that kind of info.

Thanks and it was a pleasure to read your page.

Hi there so I have 2 1200 wat kingled and a 1000wat led with a dial to turn the lights up and down now I’m just starting budding should I run both veg and bloom light and are the lights I have any good my plants are doing amazing in veg but ow it budding time and I want to know for sure lol thanks so much

Hi Chris, yes use both of the veg/bloom switches!

I have access to 8 theatre led flood par lights that are just sitting in a storage right now. I was wondering are they suitable for grow lights? The lights are Stairville LED Flood Panel 150 40° RGB from Thomann
If so, in what way they should be used?
Thank you!

Hey Jerry, Those lights would certainly “get the job” done for seedlings, the lights themselves don’t look too powerful at 18W. I would use at least four if you wanted to cover a 4×4 area, definitely experiment. Not sure of their efficiency but if you have them try it out.

Hi, firstly thanks for a great article. i’m using a 1200 watt Viparspectra on my first grow and i was wondering what you’d suggest to supplement? Would a HPS light be better than a warm light LED floodlight for blue light correction? I know u said 1-1 ratio for HpS and LED but obs i’d then be running 3000w in a 4×8 space – would that be too much?! Would a 250watt HPS bulb be okay do u think? thanks

Hi, firstly thanks for a great article. i’m using a 1200 watt Viparspectra on my first grow and i was wondering what you’d suggest to supplement? Would a HPS light be better than a warm light LED floodlight for blue light correction? I know u said 1-1 ratio for HpS and LED but obs i’d then be running 3000w in a 4×8 space which seems a lot! Would a 250watt HPS bulb be okay do u think? thanks

Do you know where to get lights with this optimum spectrum you speak of in one setup?

I’m wondering if a floodlight with 2700K warm white light, 1200 lumens, CRI > 85Ra would work as a grow light in the vegetative state? Reason I’m asking is because it also has color changing that syncs up with your cell phone to change the light color. Thanks.

Yes it will — max out the brightness!

Hello, I recently started growing hemp under a bestva 3000w led. My plants are autoflower and I want them to grow as big and as fast as possible. Should I be running my light on veg only? Or bloom and veg both? My light is about 24in above the plants

Hi Jason, I would turn both of the switches on and let it rip! Back off the light 1 foot and then turn on both of the switches, observe plant health and adjust height as necessary, good luck! -Dan

Hi there. Great article and thanks for the info.
I just have one question; I’m running a viparspectra 300w but I wasn’t clear if I should use the supplemental warm white led’s in veg stage or flower stage or both?
If you could let me know that would be great.
Many thanks

Yes some white LED’s will help balance out the spectrum of that Viparspectra. I would use it in both veg and flower for best results.

Hi there, wow so many great tips! Can we please ask a question? Our indoor plant growing device has three modes, full spectrum, Veg. and Flowering. We’re growing hot peppers. We understood that we start with full spectrum first, is that correct? Then what? At what stage switch to flowering? or Veg? or just stick to full spectrum?

I’d stick to the full spectrum! =). You can add in the others when the plants are big.

Hi, I’m growing legal cannabis and during the vegetative and early flowering phase (the 2 week “stretch” for cannabis plants) the goal is for plants with extremely short internodal distance and low, bushy growth. Currently, I’m running them under just the veg switch of my LED and I plan to continue until they begin to produce flowers, then I’ll switch to my 3000k full spectrum 600w actual draw quantum board LED. Do you think this is a good plan to produce plants with very tight internodal spacing by the time they begin to flower?

Yes the lack of red light will reduce the amount of stretch in the beginning phase of flower.

I ordered no name Chinese LED grow light listed as 800-1200w. 4 COB. Arrived 1200w. No idea of light spectrum. Switch turns on/off 2 COB’s.
Do I assume half power is 600w?
Plants seem to like two lights more than four. Currently have 5 autos growing mostly indoors.
I know asking for help with this info is a lot. I’m dealing with a language barrier.

Is there a driver exposed that would show the actual wattage of the light? Or you could also use a meter to see how much power it is drawing while on. Having a better idea of total power will help you adjust as needed.

I have a 3×4 room with a viparspectra par 600, with the intention of having a 30 in diameter plant to keep it within the specs for flowering. I’ve been running all the lights, red white and blue, the plant is growing very well but it seems to be a little too bushy. After reading your article I too turned off the blue light. Is this the right move for the light I have, or should I turn the blue back on and add more white like you mentioned in the article? I’ve always grown outdoors this is my first time indoors so any help would be helpful. Thank you

Hi John, Turning the blue off will make the plant grow bigger, you can probably drop the light a little closer to the plant with the red and blue on and it will start to stretch out the way you like and get larger. Once you get close to flower, turn on all the colors and you’ll get a great finish.

Thank you for you response.

Can you please explain me is that high peak in blue spectrum in Mars Hydro TSL2000W means that plants mostly can absorb blue light? Ratio for blue colour as you discribed to find in your post is only 2.2% in comparison with other colours. Most are green that gives that high peak in blue spectrum that’s how I understand it but is that mean that plants mostly get blue light photons from this light?
Blue: 2.2% red: 19.5% green: 78.3%

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A lot of good information, good job!

Would be great if you could advise me

I have MarsHydro TSL2000W LED light and I’m wondering if I need to add additional light to change the spectrum.

This light uses a lot of white diodes for effieciency which tends to run a little blue. Adding some additional red and deep red will increase flower production.

I have a 2000 Watt King LED when would I use the veg and bloom mode at the same time and also wanted to find out about misting the leaves with water is it okay or not

You are going to want to use both switches when in flower to get every watt you can from that light. As for misting my plants, I don’t find much benefit unless applying a solution for purpose.

This is exactly the reason I purchased from The Green Sunshine Company – Here is the Owner helping non Green Sunshine folks work their their light issues and sharing knowledge freely …. Love the ES180, best grow I’ve ever had, thanks Dan!

Awsome read brother how do I sign up for emails when you come.out with new info. Also quick question so if i wana keep mother plants and dont want them growing crazy just veg would be appropriate yea?

Thanks Andrew! Just visit our webpage at and at the bottom you can enter your email to join our newsletter. As for your moms, yes using a veg mix would be ideal.

I really liked the read. But I just wanna ask, when flowering is it better to run both veg and bloom settings all the way up? I have mine set with veg down to a minimum before it turns of veg mode and bloom all the way up when i flower.

Yes you want both switches on 100% in flower!

Very comprehensive and informative… Thank You!!
I had 2 separate single grows last year using a 600w Viperspectera in a 2×2 grow closet…. both plants vegged great, but the flowering was a bust.
After reading your article, I installed 2 clip on work lights with 100w Sylvania LED soft white floods. I’m into day 18 of 12/12 light change, she vegged great, got alot of hairs coming on, hope I have success.

Hi Greensunshine, thanks for your awesome post.

I’ve got a 2-600w viparspectra with veg and bloom switches, would you advise to keep both the blue”veg” and red”bloom” light spectrums during the veg and flowering stage ? my plants seem to be growing very nice so far and I have only been doing veg light for veg since early growth there about 20 inches now . this is my first time using led I have venom go and the temp is about 78. thanks so much also I’m going to get the light as well..

Hi was hoping for quick advice. I have 2 Aglex 1200w cob led lights both with veg and bloom switches. I’m running in a 4×4 tent is that too much light with both running full power? Draws about 200 actual watts each from thd wall. First timd grower 4 weeks into autoflowers.

Definitely not too much light . Could use more, actually.

My gorella auto have been in 5 gal pots for 11 days they are 2 inch’s tall for the past week. I’m using a visparspec 900 hung at 36 inchs with both veg and bloom on. I’m I doing it right. ANY HELP WOULD BE MUCH APPRECIATED

Hi Jim — Yep sounds right!

Very Comprehensive and well written. I’m running a Viperspectra 600w non-dimmable in a 3×3 Vivosun tent. I’ve had 2 back to back disappointing single plant grows… could well be the lighting.
Being on a fixed income, would adding a couple Sylvania 100w floods solve my issues?

Hi Alan, yes getting a couple nice white LED lights would work, also our Electric Sky Lights are a great upgrade if you’re looking for new lighting altogether.

I read through this entire article (which I rarely do) and found it extremely useful! Thank you, but I do have a question. I started my flowers later this summer (after my normal flowers bloomed and died). Problem is that I am on the west side of my apartment building so I would only ever get 4-6 hours of strong sun. To supplement the lack of sun, I bought a 44 LED Plant Grow Light – 20W grow LED light not knowing anything at all. At first it was flourishing, now it seems to have stalled on the growth as the sun is less and less so I am relying on the LED grow light more and more. Unfortunately I read your article to late and was after already blasting it with RED/WHITE/BLUE (blue light in particular). After reading this article, I turned off the blue and only RED/WHITE. Is this a good move, should I expect it to grow better now that I turned off the blue? OR should I scrap the LED and get a more robust one? IDK, it seems to work but I want my flowers to finish growing as this was the largest one yet so I am really excited to see the bloom (indoors growing only now due to weather and seasons changing closer to winter).

Hi JC — that grow light seems to put out a tiny amount of light, only 20 watts, so the stall in your growth is likely mostly due to the fact that the sun is no longer as strong! If you’re interested in a high quality light check out our shop page for Electric Sky LEDs that we developed. If you’re looking for something a little more budget conscious, a standard warm white flood light found at a hardware store is just fine for keeping plants alive during the winter!

I have 2 Bestva 2000w reflector series full spectrum LED lights. They come with a bloom and veg switch but no way to actually control output per channel.

I am running both in a 5×5 tent.

Would you still suggest that I run a 3000k white LED flood light with this setup?

Yes, white LED or a low power HPS bulb is a great addition to Purple LEDs. The best addition would be one of our Electric Sky lights, even the small ES180 would help out immensely since it is about twice as efficient as the BESTVA lights per watt.

Knowing that I need some white light, I have a 4000k 32 watt shop light… But should I aim lower for something around 3000k?

This would be for a simple 2′ by 1′ ft set up. As I get more into this hobby: your product looks fantastic and will be a future purchase! But I’m starting small
for now

Hi Trevor, Either would work, you can start with your 4000K and get good results!

We had both veg and flower switches on and our babies are beautiful… however the leaves look like they might be burning? Would love your advice

Hi Moms — the purple kind of LED grow lights emit a lot of light in a small range of color, which can be stressful to the plant (think like a laser pointer). Blue light especially can cause this stress, so would recommend backing the light off a bit! That should help. -Dan

I have inherited a Pro Grow LED 400 but the blue light (vegetation) doesn’t seem to want to turn on. The fan turns on however the lights don’t. The red flight for flowering turns on. Am I doing something incorrectly or do the blue lights burn out? Thanks for any help.

Hi Leah — sounds like the light malfunctioned and went bad. Not a normal thing for those to burn out.

Hi Dan,
Thanks for keeping us informed with great feedback!
I have two Bestva DC 2000w units in a 4×8 grow room and am just about to start my first grow.
If I am understanding this correctly, I should use both VEG and BLOOM lights throughout the entire grow and adust the light ON times for the veg and bloom stages.
18 on 6 off for veg and 12 on 12 off for bloom.
Would my assumptions be correct?

Hi Lee, yes that would work very well, experiment and see what works best for you with your light. Be sure to back them off pretty far for veg!

Hi, I have 2 1000watt Giixers or so they advertise lol, i am in early bud stage and was reading to use both veg and bloom switches during this time, is that true ? And when should i turn off veg light? Just fyi , im bringing them inside to finish off due to weather and snoops, first time trying this

Yes, that’s what you want to do!

Hello there I’m a first time grower and just found your page and love it nice work!

I have a question about a 1000w light with 2 seedlings and a Hindu Kush that had 6 weeks and was dying and I placed it under the lights and it came back, just wondering should I be using veg and bloom light option on these guys or just veg and for how long?

Thank you in advance

Hi Dave, Either is fine, without knowing what light you have, it’s hard to say. Moving the light back to 36-48 inches away would be the best bet as you recover!

Hey thanks for putting together such an informative article! I’d just like to clarify something that you’d said about bringing the blue down with the viparspectra lights. I’m using x2 “1000w” Viparspectra’s in a 8 plant set up. The lights have a setting of 1-100 on both veg & bloom. What would you set those to be during flower as I understand the lights give off more blue light than red but during flowering red is the more important light. You’d said in the article to back off on the blue light with the viparspectra but didn’t clarify if that was only during veg or not, unless I missed something. I had the settings at veg 40/bloom100 during veg and the plants are thriving but now I’m flowering I’m hesitant in what I should do? Thanks!

Hey Saxon, in flowering the plants can take more total light. You can ramp up the blue in flower. Since you want to use more total light in flower, it’s fine, just look out for any bleaching and back the lights off if you see it.

Hi Greensunshine, thanks for your great post.

I’ve got a 600w viparspectra with veg and bloom switches, would you advise to keep both the blue and red light spectrums during the flowering stage ?

Thanks for your response.

Yes — definitely keep them both on during flowering!

It has a Veg switch and a Bloom switch. I’m currently 30 days into the grow and only using Veg. Do you recommend otherwise?

Hi jiggymeister, we can’t tell from its specifications what it does. Would recommend trying it both ways to see what you prefer, this light looks to have more white light which is good for all stages of growth, not completely purple like other LED grow lights.

Dan I made the rookie mistake of only using the veg switch on during veg cycle and then turned off the veg and switched on flowering during the flowering stage; am I still OK? I’m on week 7 of flowering. Thank you

Hi Keith — Turn both of the switches on for the flowering stage next time . You can experiment if with both switches for veg as well!

Hi Dan, Thank you so much for your generosity… it’s super interesting. I am certainly going to get one of your lights, hopefully before the next grow. I need to finish this one first however – hence these 2 x questions. I have a tiny space – 60cm x 60cm and am running a Viparspectra 450 and on your advice have supplemented it with two warm LED floodlights. only 30W each unfortunately – due to space.
I am growing automatics and therefore want to maximise vegetative growth before the flowering phase… is it better to have both veg and bloom on (with the 2 x floodlights on) and back off the lighting or switch off the veg to reduce the blue (run bloom + 2 x Flood) and reduce the height? Which one would promote more growth?

And the same question for the flowering phase.
It’s summer and it gets hot – too hot, even with good ventilation – which I have. I can’t imagine I can stay much under 84 F with all three – Flood, Veg & Bloom all on at the same time on a hot day. I guess the question is if I have to make a choice – should I run the flood lights or the Veg part of the VS450. Or should I run all three and run hot?
One last question – is it stressful to the plants (in a bad way) to alternate the lighting depending on the heat of the day… on hot days switch off the Veg switch and on cooler days to run it – how important is consistency?
Thanks in advance for any advice you can offer.

Hi Dee — glad this helped you. Yes I would keep the floodlights on instead of the blue switch of the viparspectra. Plants like a consistent spectrum and actually begin to develop and adapt to a certain ratio of color, so it’s best to keep it consistent or else they’ll have a chance of getting stressed out. Find the right combination of light that is good for your heat level, and then you’re good to go!

Thanks for the great information, I am new to growing, 1st grow. My question is I have six swamp thing plants that are ready for the flower stage. I use two 1000 watt full spectrum iplantop lights. Just wanted to make sure I should use both veg and flower channels for flowering stage? Twelve hours on twelve hours off

Yep use both switches!

Thank You GreenSunshine I thought I was doing something wrong and honestly this grow didnt turn out at all like I expected

I have a Timber Grow lights 4x100w cob led light the Cobs are Vero 29’s. This is in a 2’x4′ grow tent and the light coverage and power is awesome. My only problem is I followed all the guidelines on light height and after 3 or 4 weeks I had about 20 nodes and the plants were less than a foot tall and they were more bushy than anything I have ever saw. Some say this is good but I really need them to stretch a little more in Veg but they stayed tiny now they are about 2′ tall and every branches is a cola but the sizes of the colas arent huge because there are so many of them and alot of them cant get enough light because all of the branches. These are autoflower and my cobs are 3500k. What can I do to help them stretch more as seedlings

Hi Randy that’s a great question. A high intensity light will encourage plants to go smaller. In your case I would recommend to dim the lights down to 30% or lower during the seedling stage and they’ll stretch a bit more.

Hi Dan thanks for your reply much appreciated, I did have a look at your shop before I would definitely call your LED’s an upgrade they look great!
I have just purchased my LED’s recently so going to give them a go plus add your White Light LED addition (my LED’s pull 186w avg from the wall so looking for a 90w/100w LED white light as per your calculations) my last question is should I also use the white light LED for the total duration of my grow or possibly shut it and the veg switch off for the last week to 10 days? Thanks again!

Hi there thank you for all the great info I have changed my mind on what to get a few times while reading your article and comments so best thought to ask you directly. I am in Oz and using a Green Fingers 450w Full Spectrum LED for a grow space 82cm x 50cm x 160cm. Feel like the space could do with a bit more light. I have taken your suggestion and will put both Bloom and Veg switches on now aswel as raise the light. I am at week 2 of veg and my question is I was going to purchase a 130w Dual Spectrum CFL bulb just to add to the overall PAR levels, do you think this is a good idea or have you any other advice or recommendations. Thanks again and top work on your article truly very helpful.

Hey Gerry glad you found value in it. I would go with a white LED rather than 130W dual spectrum. If you’re looking for a nicer upgrade check out our shop for our selection of Electric Sky LED lights as well. -Dan

Hey so I have a 450 watt (I know it’s not actual) viparspectra and I’m probably going to buy the floodlights because of the price and I just have a small area with only 3 plants to cover. I was wondering would it be better to buy the 80 dollar ufo red spectrum lights or do you think the flood lights are a better option for comparable price. And p.s. I also have a cfl light(i think it’s just some light my dad has in the garage that’s pretty brights and puts off more heat than the led) should I keep that light in with the led lights or is it bad to mix them?

Hey Jon, I would say the full spectrum white lights are your best bet!

Thank you for writing this article. I have learned quite a bit. Very interesting how plants work with the light spectrum, makes you wonder what can really grow.
I have a Maxsisun 300 watt LED light with both bloom and veg dials on it. I’ve been using it with only the veg light on for 28 days.
I’m starting a grow closet of marijuana here in Colorado Incase your wondering what I’m growing.
I have now turned the bloom on to give it that pink light. 75% veg 100% bloom. About how far away from my plants should they be? 2 feet? That’s where they have been at. The lights don’t seem to produce heat even when I put my hand to it. But I don’t want to take any chances and burn them by having them right up on my plants. Again, Thank you!

Hi Dustin, thank you! I don’t know the distance you should use, but here’s a good solution where you can figure out the best height. Start at 3 feet once you ramp up the light. If the plants look healthy at your new higher intensity rating for a week or two, they can handle it, and slowly drop the light 1-3 inches every few days until you find the sweet spot. You’re not missing that much if the light is a little further away. Good luck. – Dan

Hi I guess this is a stupid question but I was wondering can you put a red mica sheet in front of a LED light to change the spectrum? Would that work?

Hi Julien! Not a bad question at all. Some horticultural scientists back in the day did this exact thing to change the spectrum of lights. You’ll probably find the best results by introducing some other light sources, since the mica sheet would block some light. Dan

Hi Dan,
Thank you kindly for sharing your wealth knowledge and information with the world.

Started my first grow, 5 sativa photos in a 4×4 grow tent, using two 900w Phlizon LEDs. Used your reccommendation to flip both veg and bloom switches and could see boost in growth intensity in the first 24 hours – thank you for the tip!

My question is, always kept the lights 24 inches off the canopy with just the veg switch turned on. Now that both veg and bloom are on, i would like to follow your suggestion and “back the lights off” before getting signs of plant damage. Can you share some insight on distance between light and canopy when both veg and bloom switches are on? I would like to max-out yield without hurting the plants. Have no clue what distance to back the lights off to?

Grateful for any insight you can provide.

Hey Paul! As long as your plants look healthy, they are OK. Backing lights off to 3-4 feet is nothing to be bashful of, it’s best to keep them further away with the increased power. If they look happy, slowly adjust. That’s it! Glad you found this valuable – Dan

Hi, can you give a very enthusiastic new grower some clarification amongst the conflicting advice I’ve read online? Yesterday I took delivery if the WAKYME 12000 watt full spec grow canopy, 120 leds x 10 watt, with three fans, veg and growth buttons. I can’t find anywhere the true output but I think 10watt is very , very high? Manufacturers have told me to keep both veg and bloom running together during the flowering phase but that introducing red into the early part / veg cycle will force the plants to flower too early, thus stunting potential growth. What do you think about that? They also advise to keep the lights no closer than 24inches above the plants. Really? Won’t that make the seedlings stretch up and become leggy ? I currently have my first ever batch of plants grown from seed on the windowsill and at 8 weeks old they are 3 times taller than they should be., ridiculously leggy. Manufacturers say if I out them under the grow lights now , to use blue only as this will reboot them into growing thick and strong. Won’t that make them even more leggy? Confused behind confusion now lol. Can u help? Can leggy plants be saved. With lights? There’s over 50 of them all and they are all different heights so what should I do with them now I have lights?

Hi Lisa, not sure what plants you’re growing, but red light won’t necessarily force plants into flowering “early”. Tomato and Pepper plants, for example create flowers as they grow during “vegetative growth” and this is normal. For photoperiod plants that sense day/night red light won’t make those plants go into flowering. The sun has plenty of red light in it, for example. There are some strange recommendations out there!

If your plants are ridiculously leggy (again not sure what plants they are) no light will magically make them short again. Putting them under a normal light source with red and blue light will help them grow great again. You could try to use mostly blue light, that would encourage the plants to grow smaller.

You may be best to take cuttings of your plants and start fresh under grow light, or just grow all of your plants out and hope for the best. I’d probably go the 2nd route and get creative training your plants. You can “cut down” the main stalk as long as there are healthy leaves left, as long as yourt plant is healthy it will grow back nice and bushy. do this after transitioning to your grow light for a couple weeks.

Hi, dan I am using a Viparspectra 900 with the veg 1to 100 setting and bloom 1to 100 setting . What setting should I set it for the veg state? And what for the flowering state ?
I have ordered your es300 for my grow tent but I am using the Viparspectra till it arrives to veg my clones. When it arrives I will move 2 in to my 2×4 grow tent with the es300 but will still be growing 2 outside of my tent with the Viparspectra 900 any advice would be much appreciated.

Hey Mark, I’d probably keep both of the switches on for veg and back off the light a bit. If not could just run veg. Hope it helps!

Thank you for getting back to me. I really appreciate your help. From your replies I should use the two viparspectra 600w lamps. For the 400watt which is the better option the HPS or the metal halide? As I cannot use both at the same time. I could use the metal halide for veg and HPS for flowering or use one for both cycles. Which is the best way to go? Do I need the 50W Warm White LED Flood Light and the HIGROW 36W All Deep Red 660nm LED Grow Light Bulb as well? Please advise.
Thank you

Thanks this has been informative. I’m starting to regret not reading as much before i bought an LED fixture. What do you think about a Growlite WBV-320L, I was under the impression that it would be good all the way through, but I’m starting to see that i was mistaken.

It should have enough power to grow your plants all the way through. It is a cool white fixture, so your yield may not be the most it could be in flower, but it should prodice some higher quality end result!

I was reading your posts before I received your reply. First let me say thank you for replying.I really appreciate your help. I went out and I purchased a 50W Warm White LED Flood Light and I also purchased the HIGROW 36W All Deep Red 660nm LED Grow Light Bulb. i want the full spectrum for my room. I also have a 400watt HPS that I could put in the room. Like I said I want to complete the spectrum for best results. Now knowing what lights I have what lights should I use for best results?

Hi Scott, I would use them all! That would create a nice growing environment for your plants.

Hi Dan,
I have two viparspectra 600w lamps in a 5′ x 5′ tent.My lights don’t have dimmer. This is my first go it this. I’ve had my plant under the lights for two weeks with not much growth? I only have the veg light on. I do have a 400watt metal halide should I incorporate that light in my tent or just put on the bloom light on as well as the veg light? Any help would be greatly appreciated. Please advise.

Yes — I would turn both switches on and keep them high above your canopy. The Metal Halide would actually be a perfect supplemental light for a wide spectrum in your grow, even during flower. With a 5×5 tent you have plenty of room to experiment.

Hi I have a greenfingers 1000w working great on both veg and bloom switch came home today and room is red instead of purple and I’m freaking out!

See also  thin weed seed with hooks

will add a warm white bulb tomorrow just wondering if red only means blue chip or somethings wrong

Great info thank you.
I have a maxisunn 300 watt dimmable grow light in a 4x4x7. Eventually I will buy another one. I just would like some feed back on this led light. Because I notice That the veg is a lot brighter then the bloom.

Hey Gabe, couldn’t find much usable information about this light

Hi there I just purchased an inivisible sun ish250, it’s the one with the older diodes not the latest ones and I was wondering if I was on the right track? I’m in a 3×3 and haven’t started because I’m not sure if I haven enough light to get the full cycle done? Any help would be awesome TIA

You’ll be totally fine. That will be plenty of light

Thanks for offering help.
i have 2 simulight 540 watt LED’s. model 9614G. they have 3 settings. and i have a 3′ x 5′ space.
Are they a good light?
Is it too much power?
And how should i operate the veg, grow, bloom switches.
any advice would be much appreciated.

Thanks for a great article! I have 2 platinum LED 300’s. They draw 180 watts each, and have been doing pretty well on their own. I have a couple of CFL bulbs, previously used for sprouting, and I wonder if they would help even out my spectrum. One is 26w (=130w incandescent) at 6400k. The other is 60w (=250w+ Incandescent) at 5500k. Would either of these bulbs work, or would you recommend something else?

Hey Frank! The CFLs probably won’t change that much since they’re a very “distributed” light source in your situation. The 2 platinum LEDs are probably fine, you may want to look for a “white” LED light source if you’re up for some experimentation.

In regards to the flood lamp, do you suggest just keeping it on the floor or trying to hang it also? I have the same Viparspectra light and setup as Sillib does.

You would want to hang it above your plants with Rope Ratchet hangers.

Can you give some advice on the HG800? Hipargero COB + LEDS. The Spectrum for borh switches and for veg only seems quite balanced. Any feedback? Tent is 80x80x180cm.

Looks decently balanced with the White COBs to me!

hi dan , should i veg with veg and bloom both at 100? if the plant can handle it. or still lower the blue? i have 600watt vipaspectra timer controle series

Play with both! Recommend experimenting with 50% veg / 100% bloom, maybe 75% / 75% for veg.

hi i have a vipaspectra 600 looking everywhere for this information. their is a veg and bloom chanel both adjustable from zero to 100. following your advice i went from 100 veg 20 bloom to 100 100. Is their such thing as to much light such as going 100 100. should i dile the blue down further and favour red. why does everyone else reccomend the opposite hope this fixes my yields

Yes — In Veg you want more red, since that is your “growing power”. A higher proportion of red in veg will encourage the plants to grow faster in veg. In flower, they’ll appreciate both of the spectra turned all the way up. Cheers!

Thank you for the reply! Glad I was able to make a correction in the right direction. Cant wait to see how these girls flower out!

Last question; Would you recommend taking the plastic part off the flood light that is meant to protect it from dirt and water? Would it make the light more intense?

You can experiment with that. The lenses on the unit may help keep light stay in a more focused beam. Have fun!

Didnt realize this article was so fresh, glad to see youre still active in the comments section!

I have a viparspectra 600, and as you stated in the article, it really lacks a red spectrum. I purchased a ‘HIGROW 36W All Deep Red 660nm LED Grow Light Bulb’ to enhance the red spectrum. I am in a 3×2 tent.

I went ahead and purchased the LED flood light as well, and am just curious what spectrum I should expect from the flood light.

Cheers! You picked up the right stuff for a nice budget correction. The flood light is basic but gets the job done for a good price. It will really help round out the spectrum in your grow tent. I would recommend hanging all the lights as high as you can and close together to get the best spectrum uniformity.

To your healthy plants

great info
i just start a 2 grow tent configuration ,
1 4×4 with 600w HPS
2 3×3 with 1500w COB blue light
i wanted to veg on the 1500wCOB and move after to HPS 600w to flower , will this affect my plants ?
also have more led lighs around to play with , 2000wled viparspectra and 1200w led,
what can be a proper mix setup of lights ?

Your plants will do fine with HPS in flower and 1500W COB in veg. I am not sure of spectrum, but you described it as blue. Would recommend placing some white in veg as well for less shock moving to HPS.

For the extra LED lights, use them in flower with HPS for extra yield.

How would you use a viparspectra 900 and 2 viparspectra 600 for a veg and flower room?

Unsure of what room size you’re working with, however I would definitely turn on both switches in veg and back the lights off for bigger plants with less blue light.

I’m so happy that I came across this article. I have 4 Advanced LED 200 XTE lights and 2 Advanced LED 100 ‘s in a 5×5 tent. I’m growing scrog style and though I’ve observed Advanced Led’s recommended miniumum distance of 24″ , most times being 26-30″ away, I’ve always had light burn issues, leaves brown and shriveled, and the top of my buds were white. The garden is in first week of flower now and I’ll follow your advice to dial both grow and bloom up to 100%-well, I may back off on the blue just a tad now that I know that’s the spectrum that responsible for burning. As I progress into flower should I dial down the blue back to <30% and leave the bloom dial at 100%?
Temp wise, I keep the grow room in the upper 70's as it is, these lights have IR & UV diodes so when working under them it can be uncomfortably warm, and I've actually had a sunburn after one extended session.

I’m glad you found value in the article. Blue and UV are the “strongest” wavelengths and can cause light burn. However, it is one of the lowest-needed colors for growth. It will harden leaves, make the leaves smaller, and make the plant shorter, which is good a good strategy for some species, but not for ones where we want the most yield and strongest “bush” type plants.

I would experiment turning blue mostly off in veg and in flower if you think the plants can handle it, crank it up. Should have plenty of power in there even with the blues turned down a bit. I wouldn’t feel like you’re missing out on anything if you weren’t running full power on 1000W.

That was very informative and genres of you to share this information thanks dan i am only new to grow and have made mistakes and still making them the biggest being farting around with the wrong lights if you are unsure about your lights do your self a favor if not your self do it for your plants scrape up the money and buy an es300

Thanks Jaffa! Glad you received value from it.

Hey Dan, Two thumbs up for the article. My question to you is, I currently have a Spider Farmer 600w LED in a 3×3 tent. What is your recommendation on how to adjust my lighting?

Hey Todd, Thanks!

I looked up the Spider Farmer 600w and they have an interesting way of putting together the spectrums. The “Flower” spectrum is quite low in wattage, and the veg is very high, which is a different configuration I’ve seen most lights do.

I would always leave “flower” on on full blast.

When you’re in veg, what I would do is turn down the “veg” portion to about half and see how that works out for you to cut the blue down a little bit. Once you move into the later stages of veg and into flower, let er’ rip full 100%

Let me know if you have any Q’s!

Hi Dan and thank you so much. I have a Mars Pro ll Epistar 120 LED in a 24x48x70 tent. I am very new to all this and need any help I can get. Please let me know about this light in this set-up and if I should supplement or do anything else you mentioned or even did not mention. If needed, I do plan on buying a better light (yours) when I get the funds. Again I thank you and look forward to your reply!!

Hey Greg! Just checked into that one for you. Luckily the spectrum is pretty balanced already between red and blue:

I definitely recommend keeping both switches on for the entirety of your grow cycle.

Lots of airflow and higher temps will be key for you to get the most yields as stated in the article.

The light does lack some infrared light and green/yellow light, so you’ll want to “train” your plants to be a flat table by topping or scrog-ing because the light may not completely penetrate the canopy, so you’ll want to keep that pretty shallow.

Upgrades for you in the future would be to add some white light in there, but it isn’t critical, you should get some great results with your current grow light! Keep growing and when you’re ready to fill out that tent some more, add some more light sources to get more yield.

Let me know if you have any other questions!

Really good read, thank you for the info.
One question… I just purchased a 1500 watt COB LED set up. I got a great price for it and is full spectrum LED. The light is more Pink looking,/red. It’s only got a on/off switch and seems to be a great light.
How do I know if it’s any good or not?
It’s a BestVA 1500 COB LED, can you check it out and please get back to me?
Thanks for the excellent read,

Hey Doc GreenThumbs,

I would say the BestVA is “OK”. The wattage on it is actually 300W, I am not sure where they are getting “1500 watt” from.

The “COB” diodes that they are using are an older, lesser efficient style, but will “do just fine” however there is some better out there. I would say this “300W” light would be on par with a flagship “150W” “200W” LED light. Generally speaking, the cheaper LEDs found on Amazon are 50-75% as efficient vs higher end LEDs.

All this to say you got a great deal on it, if you’re keeping it, I would definitely consider adding white LED floodlights to the mix (linked in the article) since that will 1) reduce amount of blue ratio and 2) fill in the white and orange spectrums for better growth.

If you’re in the market for higher quality LEDs please stay tuned because we have an announcement for that coming up…

Let me know if you have any other questions, happy to help!

Thanks for the information really good stuff just getting started with a cheap greenhouse so I have GPS light and led spectrum lighting have good seeds and will be trying on 3 small plants. Thanks

Hey Tony, glad you enjoyed the article! Best of luck growing, stay green and keep at it

Autoflower cannabis plant light schedule

When growing autoflowering cannabis seeds there is one fundamental difference to ‘traditional’ photoperiod feminised seeds. That is the ability of autos to bloom under any light cycle provided by the grower. You can bloom an autoflower indoors under 12, 18 or 24 hours of daily indoor light. Or you can bloom autoflower plants outdoors where they will bloom happily irrespective of how many daily light hours are received.

Autoflower plants don’t have a photoperiod dependency that requires daily light to be 12 hours (or less) in order to bloom. Apart from that, autoflowers grow like normal cannabis, producing the same terpenes and cannabinoids. Quality levels/cannabinoid levels from the best autos are on a par with the best photoperiod strains. You can use the same nutrients and grow systems for your autos as you would use when growing photoperiod feminised strains.

So what is the optimised autoflower light cycle? Does one particular autoflower light schedule produce particularly good results? How do the results from an autoflower 24 hour light cycle compare with an autoflower light cycle of 12/12?

The life cycle of autoflower cannabis plants

When considering the optimised light schedule for autoflowers it should be remembered that in many ways the autoflower plant biology is very similar to that of photoperiod feminised strains. Light is the source of energy that powers the plant biochemistry. Those biochemical reactions produce the same terpenes, cannabinoids, leaf material, roots etc whether they happen in plants grown from autoflower seeds or feminised cannabis seeds.

The only real difference between autoflowering genetics and feminised genetics is that the autoflower genetics have been released from the shackles of photo-dependency thanks to some clever breeding by talented geneticists. This allows the grower new liberties and the ability to grow with the light cycle which most suits them.

For example, you can bloom autos under a 12/12 light cycle (12 hours of daily light followed by 12 hours of darkness) if you wish to grow/bloom your autos in the same room that your feminised strains are blooming in. Or you can grow/bloom autoflower seeds under 18-24 hours of daily light in the same room that you use for your mother plants/vegetative growth.

When contemplating the best light cycle for autoflowers remember that the main benefit of autos is their adaptability and speed of growth. Some growers keep separate mother rooms (18/6 light cycle) as well as a bloom room (12/12 light schedule). Autoflowers will grow and bloom quite happily in either environment. When growing autoflower seeds, you are in charge and can dictate the autoflower light cycle in order to deliver maximum convenience for you.

What is the best light cycle for autoflowers?

The best light cycle for autoflowers is, in many ways, the light cycle which is most convenient for you. Autoflower plants adapt to your situation, allowing you to use a light cycle that suits your needs.

If your grow room gets cold during the ‘lights-out’ period in winter then you may want to run a 24 hour autoflower light cycle, using the heat from your grow lights to keep grow room temperatures as high as possible. Conversely, if the grow room gets too hot during summer you may prefer to run a 12/12 autoflower light schedule with lights on only during the cooler evening hours.

It’s quite possible that there isn’t a single optimised autoflower light schedule. Instead, you will find that autoflower seeds will grow well under several different light cycles. Autos have earned their reputation for being flexible and adaptable yet still delivering superb results under a broad range of autoflower light cycles in a wide range of grow systems/methods.

Most growers lean towards an autoflower light schedule using 18-20 hours of daily light. This gives great results. With the best modern autoflower seeds you can expect superb quality levels on a par with the best feminised seeds. Auto Skywalker Haze has been independently confirmed to have THC levels over 26%. Many feminised cannabis seeds struggle to deliver such THC levels!

Total light hours for autoflower vs feminised seeds

Autoflower seeds Feminised seeds
Around 1400 (70 x 20) hours Around 1386 hours
When considering how much light does an autoflower need, it’s worth noting that a typical autoflower takes around 70 days to from from seed to harvest with 20 hours of daily light. In comparison, a photoperiod cannabis strain grown from seeds might take 5 weeks of 18/6 vegetative growth (630 hours) and 9 weeks of 12/12 bloom (756 hours), so around 1386 hours in total.

Autoflower strains can cram their life cycle into a shorter start-to-finish time period

The 1386 light hours required to grow a ‘typical’ feminised strain is remarkably close to the 1400 hours of light required for autos. However autos fit their growth into 70 days or so, compared to the feminised cannabis seed grow cycle of 98 days (5 weeks veg & 9 weeks bloom). That may be a valuable time saving for some growers.

Of course, it should be recognised that there are some feminised sativa/Haze strains that can take 14+weeks in bloom as there are auto strains that can take 13 weeks or more from autoflower seed to harvest.

For many people, both professional and hobby growers, the faster seed-to-harvest growth cycle of autoflowers makes them much more convenient. But it’s worth adding that some autoflower strains such as Auto Blueberry and Auto Blackberry Kush can be ready to harvest in as little as 8-9 weeks after germination. On the other hand, some autoflower strains such as Auto Desfran and Auto Ultimate can take 13 weeks (or longer) of a 20/4 autoflower light cycle.

Light times for autoflowers can be adjusted to suit the convenience of the grower, that’s one of the reasons that so many indoor growers like to keep a spare pack of autoflower seeds in the fridge. You can grow autos under 12 hours of daily light or 18-24 hours. The choice is yours depending on what works best for you and what else you are growing at the same time.

12/12 light cycle for autoflowers

A 12/12 light cycle is popular for blooming feminised cannabis strains. The lights are on for 12 hours and then off for 12 hours. Very often, growers may have spare space in their flowering tent and they can put this to good use by planting an autoflower seed or two. However, autoflowers will grow faster with better yields under 18, 20 or 24 hours of daily light than they will on a 12/12 light cycle.

18/6 light cycle for autoflowers

How much light for autoflowers? What is the optimum autoflower seeds light cycle? These are two of the most common questions. The 18/6 autoflower light schedule is very common. It means 18 hours of daily light is followed by 6 hours of darkness. Many growers also use this light cycle for vegetative growth of their feminised cannabis seeds. An 18/6 autoflower cannabis light cycle tends to produce harvests around 10-11 weeks after germination.

20/4 light cycle for autoflowers

Perhaps the most common autoflower light schedule, and the one which Dutch Passion most often recommends is the 20/4 light schedule. This uses 20 hours of ‘lights on’ followed by 4 hours of darkness in each 24-hour time period. This light schedule delivers great results and seems to give the plants a healthy autoflower light cycle all the way from seed to harvest.

24hr light cycle for autoflowers

A 24 hour light for autoflowers is often popular during cooler winter months. In winter, grow room temperatures can often decrease faster than the grower would like during periods of darkness when the grow lights are switched off. One way to mitigate cold grow room temperatures is to grow autoflower seeds under 24 hour light. The grow light helps maintain grow room temperatures.

It’s worth noting that not all auto growers recommend the 24 hour light cycle, feeling that an hour or two of darkness has certain benefits for auto plant development. But this view isn’t universally held.

A 24 hour autoflower light cycle is also popular with those that grow their autos in the same room that they use for vegging feminised seedlings or keeping their mother plants. It’s also worth adding that those with particularly powerful lights and high PPFD levels may find that the DLI (daily light integral) is simply too much for some strains when the lights are on a 24 hour autoflower light schedule . Problems can arise when autoflowers are bathed in excessively high light intensities for 24 hours each day. If issues are seen (such as bleached flowers) they can be solved by reducing light intensity and/or giving the plants a few hours of darkness each day.

LED grow lights and light spectrum for indoor autoflowers

Which is the best light for autoflowers? What light for autoflowers will give the best result? Many professional growers would only consider LED grow lights due to their greater efficiency, superior spectrum, reduced levels of heat stress and long life (compared to HPS). Dutch Passion’s best autoflower THC levels (measured by independent test labs) have always been produced with LED grow lights rather than HPS or ceramic metal halide.

What light cycle for autoflower with LED grow lights? Most growers tend to use a 20/4 autoflower grow light schedule, but as previously explained, autoflower seeds will grow well under a range of autoflower light cycles. The autoflower-to-light distance needs to considered. Check the manufacturers recommendations at each stage of growth. Some lights will need to be around 30cm above the canopy, other lights will need much greater distances.

In general the best light for autoflowers is LED. But HPS light delivers great results too for those on a budget. The only remaining benefit for HPS over LED is that the initial HPS purchase cost is much lower. LED light for autoflower has a better spectrum with more usable blue & red light wavelengths and fewer of the less useful orange/green/yellow wavelengths. LED delivers a purpose-designed autoflower light spectrum.

These days the ‘blurple’ (blue/purple) autoflower light spectrum seen in the early LED grow lights has been largely replaced with a more eye-friendly warm-white spectrum which is easy to work in and produces excellent results.

Of course it is impossible to grow an autoflower without light, light is the energy source which drives photosynthesis. Without light, cannabis simply cannot grow. But get the right conditions combined with the best cannabis seeds and 25% THC levels are yours for the taking.

Autoflowers light schedule FAQ

Many people feel that autoflowers are a little easier and more forgiving to grow than photoperiod feminised cannabis strains. Autoflowering cannabis seeds can be grown and bloomed under a wide variety of autoflower light cycles and spectrums. For the best results and maximised potency, it is recommended to grow autos under good quality modern LED grow lights with around 20 hours of daily light.

Autoflowers don’t necessarily need a dark cycle. You can grow them under an autoflower 24 hour light from seed to harvest. Many people do just that whereas others feel that they get slightly better results with a 20/4 or perhaps 18/6 autoflower light cycle.

Yes, changing the autflower light cycle can be done without stressing the plant. For example, if you are growing indoors with 20/4 autoflower light cycle, you can easily change the light cycle to 12/12 (e.g. to allow blooming to begin on nearby photoperiod feminised plants). This doesn’t cause any stress to the auto. However, it should be noted that reducing the number of daily light hours can increase the flowering time and/or the yield of your autoflower in some circumstances.

To get the best results and the heaviest harvests outdoors, aim to grow autoflowers in the three sunniest months of the year with plenty of direct sunlight. Growing autoflowers without direct sunglight will result in airy, light buds and poor quality taste/potency. Growing autoflowers outdoors without direct sunlight would produce similar results to an under-powered indoor grow room.

Yes, excessive light will stunt your autoflower plant growth. One of the dangers of using some of the latest very high powered LED grow lights is that they may output a little too much intensity in some situations. However, many lights have adjustable power levels allowing the user to adjust light intensity (or raise LED light height). LED bar lights have different recommended hanging heights compared to LED lights that concentrate their LED chips on a single compact panel. The better LED manufacturers will be able to recommend the right intensity/hanging heights. In many cases, you will be able to see online grow diaries or social media posts illustrating the correct use of various brands of LED grow lights at different states of the plant growth.

Growing autoflower cannabis seeds is fast and easy

The main message about growing autoflowering cannabis seeds is that they are a proven, simple and rapid way to a high quality harvest. Most growers tend to use a 20/4 autoflower light cycle but autoflower seeds are flexible enough to adapt to whatever light schedule you wish to use. These days exceeding 25% THC levels is quite possible with the best autoflower seeds. Choose the highest quality seeds that you can find from a supplier with a reputation you can trust. And enjoy the grow!

How Many Grow Lights Do Your Plants Need?

How much light is enough to promote excellent growth in my plants?

That’s a question a lot of growers ask themselves at some point when trying to decide on the best grow light for their plants. Whether you’re new to growing or you’ve been growing for a long time, figuring out how much light you need can be tricky.

If you’re feeling overwhelmed, don’t worry. We’ve created this guide to help you determine exactly how much light your plants will need in a grow tent or grow room environment.

Table of Contents

If you’re ready to grow your own plants and want to know how much light they’ll need, read on. We’ll give you tips on what to look for and what factors to keep in mind when considering your plants’ lighting needs.

Light Coverage

Knowing how much light your plants need isn’t as simple as choosing any light and then hoping for the best. You’ll have to take into account two important factors:

  1. Plant Coverage — This is pretty self explanatory and means the amount of light each individual plant will receive.
  2. Canopy Coverage — This type of coverage refers to the light that will be spread over the entire group of plants in your grow tent, otherwise known as the canopy.

Whether you’re going with plant coverage or canopy coverage, it’s essential to know how much PAR or lumens you’re going to need for optimal growth. Remember:

  • Lumens measure the intensity of an HID light, which includes HPS grow lights , MH grow lights , and CMH grow lights .
  • PAR , or photosynthetically active radiation, is used to measure the intensity of LED grow lights .

You might be asking yourself, “ Why do I need to factor lumens/PAR? Can’t I just use a certain number of watts per square foot in my grow room? ” While you could just base the amount of necessary light for your plants on the size of your grow room or grow tent, doing so won’t give you enough light intensity for all of your plants .

  • Plants require a certain amount of lumens or PAR to achieve optimal growth.
  • As such, it’s best to figure out the exact amount of lumens/PAR the specific plants you’re growing will need.
    • Notice that we’re ditching the whole “x-watts/per sq.ft.” method. Now, the coverage area of any given light will have varying PAR/lumens the further out from the center you go. That’s why if you have a large growing area and need to use multiple lights, PAR and lumens is going to be especially handy.

    Research Your Plants Specific Lumen/PAR Needs

    It’s important that you research the lighting needs of the plants you plan on growing. While you could potentially get decent results from simply estimating, you’ll see the best yields and the healthiest plants with proper lighting.

    • Weak Light Intensity : If you don’t provide enough light for your plants, they’ll struggle to grow. This can lead to stunted plants and weak results. Not to mention, you simply won’t get the flavors and aromas you want out of your plants.
    • Too Much Light Intensity : Too strong of a light will also cause problems for your grow. If you give your plants more light intensity than what they need, you could end up burning them.

    If you want to determine how much PAR or how many lumens you’ll need for each of your plants, it’s pretty simple. All you have to do is a bit of research to find the right values for the plants you want to grow.

    • Leafy greens like lettuce and spinach, for example, would need a PAR value of around 200 .
    • Meanwhile tomatoes, which flower and produce fruit, would need a PAR value of 400 to 500 .

    Once you’ve figured out the lumens/PAR your plants will need, finding the right light or lights for your grow tent will be a lot easier.

    Determining the Coverage for Your Canopy

    Once you know what your plants need to grow, it’s time to figure out how much coverage you need.

    But to figure that out, you’ve got to first measure the size of the overall canopy you need to light.

    1. Measure your canopy’s length and width : Your canopy is the part of your plants that absorb light. This is what you want to measure when considering grow lights. Measuring the entire grow space will give you an inaccurate estimate of the necessary light for your plants.
      • Note: the size of your growing area is important because it’s the area you can fit a certain amount of plants in.
    2. Measure your canopy’s depth : Don’t overlook the depth of your canopy. You’ll need lights that are strong enough to penetrate deep into your plants. Simply covering the tops of your plants won’t be enough.
    3. Find the Best Grow Light(s) for Your Grow Tent or Grow Room : Now that you’ve determined the size and depth of your canopy, as well as the lumens/PAR you need, you can make the most informed decision and purchase the right grow light.
      • By knowing the PAR/Lumens your plants need, you’ll be able to determine how strong of a light you need.
      • By knowing how much area you need to cover, you can figure out how strong of a light you’ll need so that it can spread the light it gives off the higher its raised.

    How to Figure Out Many Grow Lights You Actually Need

    As you can probably tell by now, asking yourself how many grow lights you need upfront is a bit too tricky and broad. Ultimately, a better question to ask yourself is:

    How much strength and light intensity do my plants need, and how many lights will I need to achieve this goal?

    Thankfully, you now know how to get the answer to that question. You’ve determined the amount of lumens or PAR that each of the plants you’re growing needs . You’ve also figured out the light intensity required for the size and depth of your canopy .

    How to Calculate the Number of Lights You Need

    Now that you have a general idea of how grow lights, lumens, and PAR work in your grow room, the question remains:

    How exactly do you calculate the number of grow lights necessary for a successful harvest?

    Here are some step-by-step instructions to help you figure out how many grow lights you’ll need.

    1. Research the lumen and PAR requirements of the plants you plan on growing. Are you growing tomatoes? Cucumbers? Peppers? Herbs? Whatever it is you plan on growing is going to have unique lumen/PAR requirements, so start there when trying to decide how many plants you’ll need in your grow room.
      1. Research the minimum and maximum requirements for your plants. Tomatoes, for example, have a minimum PAR requirement of 400 and a maximum PAR requirement of 500.
      2. Remember: The outer edges of your grow light’s coverage are weaker. If you’re only using a single light, keep in mind that the outer parts of your canopy will have weaker light intensity. Depending on the plant, you may need to invest in more than one light to ensure your entire canopy is receiving strong doses of light.
      1. Keep in mind the size of the plants you’re going to grow. Ideally, you want to avoid crowding your plants together. For best results, be sure your plants have adequate space so they can grow comfortably.
        • If you have a small grow space but you want to grow large plants, you may only be able to fit 1 to 2.
        • If you’re growing small plants, you’ll realistically be able to fit more in that same small grow space.
        • Whatever the case may be, make sure you account for their growth so you have enough space for fully-formed plants.
      1. Consider your grow light placement if you’re using multiple lights. If you need even coverage across your canopy, aligning multiple lights will essentially create a third intense point by overlapping the light coverage on the edge of each grow light. This will give you 2 or more strong points of light coming from the center of the light footprint, as well as intense light in the places where intensity would normally drop off.

      Determining the Necessary Wattage for Your Plants

      Figuring out the necessary lumens/PAR for your plants will determine the wattage you need from your grow lights.

      When growing with HIDs (HPS and MH lights, for example), consider these options:

      • Yield Lab 400W HPS+MH Air Cool Hood Reflector Grow Light Kit(Price: $189.95) — A 400w HPS light provides 55,000 lumens , while a 400w MH light generates 36,000 lumens . This light intensity is enough to provide coverage for 1 to 2 plants .
      • Yield Lab 600W HPS+MH Air Cool Hood Reflector Grow Light Kit(Price: $219.95) — This grow light kit can deliver 90,000 lumens with its HPS bulb and 61,000 lumens with its MH bulb. As such, it could provide solid coverage for up to 4 plants .
      • Yield Lab 1000W HPS+MH Cool Hood Reflector Grow Light Kit(Price: $239.95) — With a 1000w grow light, you’ll get 130,000 lumens from an HPS bulb and 110,000 lumens from an MH bulb. That’s sufficient to provide coverage for up to 6 plants .

      If you’re using LED lights in your grow tent, you should consider these LEDs and their values:

      • S270 Advance Spectrum MAX LED Grow Light Kit(Price: $399.95) — An LED grow light panel like this S270 has a wattage of 220w , though its HID equivalent is 300w . The ideal footprint of this LED light 6sqft . Its max PAR rating is 455 PPFD at a 24-inch height. This makes it recommended for 1 to 2 plants .
      • S450 Advance Spectrum MAX LED Grow Light Panel(Price: $595.95) — This LED grow light runs off of 320w with an HID equivalent of 600w , making it a super powerful light. It has a footprint of 12sqft at a 3ft height and 17.5sqft at a 4ft height . It also has a PAR rating of 645 PPFD at a 12-inch height, so you can grow 4 to 5 plants through the vegging and flowering stages with no issues.
      • S900 Advance Spectrum MAX LED Grow Light Panel(Price: $995.95) — You’ll get a lot of power from an LED like this. Its actual wattage is 605w , but it has an HID equivalent of 1200w . The PAR rating for this light is 1131 PPFD at a 12-inch height. That means its footprint of 21sqft at 3ft height or 30sqft at 4ft height will provide coverage for 7 to 10 plants .

      As you can see, grow lights with different wattages provide coverage for different numbers of plants. The key is to find a grow light that has the right amount of lumens or PAR for the plants you’re growing — and from there you’ll decide on wattage.

      Need Stronger Coverage? Here’s What to Do

      Now, lumens and PAR begin to weaken on the outer edges of that footprint. You’ll want to keep your plants well within that footprint . If you’re growing a lot of plants in a larger space, your best bet is to install multiple grow lights to overlap those weak points .

      • For more intense coverage, one option is to lower your light closer to your plants. The lower a light is, the more intensely your plants will feel it. However, doing that will decrease your coverage area.
      • For increase intensity, you can add more light(s) to your grow. This has the potential for increase PAR significantly, so it’ important to raise or dim your lights if it’s starting to get overwhelming for your plants.

      Need to Cover More of Your Canopy with Light? Here’s the Solution

      If you need to cover a large area (like in a commercial grow, for example), you’ll want to use multiple high lumen output grow lights that you can hang higher than usual. Multiple lights also help give your plants much more intensity- as we’ve already demonstrated. But there are a couple of key things to look out for when you need a larger footprint across your canopy:

      • Hanging Lights Higher Increases Coverage Area, Lowers Intensity– To get more coverage, the first thing to do would be to raise your lights. Keep in mind the higher you position the lights in your grow tent, the weaker their intensity will be on your plants. So be aware of how much light you’re sacrificing if you need to raise your light.
      • Re-evaluate your needs– If your plants need more intensity and/or coverage than you’re giving them and you’re running multiple lights already, evaluate the lighting you have. You may need to upgrade your lighting to stronger lights.

      The Best Grow Lights for Your Grow Room

      Now that you know the importance of lumens and PAR in relation to your grow room, it’s time to pick out the best light or lights for your grow room. Below are some of our top recommendations. Whether you’re going with HIDs or LEDs, we’re sure you’ll find the perfect light grow light for your plants.

      Editor’s Choice: Yield Lab 600W HPS+MH Air Cool Hood Reflector Grow Light Kit and S450 Advance Spectrum MAX LED Grow Light Panel

      If you want an all-around excellent HID grow light, we recommend the Yield Lab 600W HPS+MH Air Cool Hood Reflector Grow Light Kit .

      This HID kit will give you great coverage and light intensity for up to 6 plants . And because it includes both an HPS bulb and MH bulb, your plants will be good to go for their vegetative and flowering stages.

      Though HIDs are known for higher temperatures than LEDs, you can keep the light’s heat controlled with the digital dimming ballast . On top of that, this kit also features an air cool hood , so your grow room’s temperatures will never reach extreme levels.

      HPS and MH Grow Light Specs

      • Wattage : 600w
      • Lumen Output : 90,000 lumens (HPS bulb); 61,000 lumens (MH bulb)
      • Coverage : 4 plants ( 2×4 grow tent or 4×4 grow tent )

      Speaking of great grow lights, the S450 Advance Spectrum MAX LED Grow Light Panel is an excellent choice for growers of all skill levels.

      This LED grow light provides coverage for up to 6 plants . And because it uses up a fraction of the wattage of its 600w HID equivalent, it also means a lower electric bill in the long run. Not to mention, LEDs naturally run cooler than HIDs, which means less ventilation equipment in your grow tent.

      LED grow lights are known for their versatility . This LED panel is ideal for grow tents of varying sizes , from 2×4 tents to 4×4 tents. It’s also a solid choice for 4×5 all-in-one grow tents with separate sections for vegging/flowering and clones.

      LED Grow Light Specs

      • Wattage : 320w
      • HID Equivalent : 600w
      • Max PAR Rating : 645 PPFD at a 12-inch height
      • Coverage : 4 to 5 plants (2×4 grow tent, 4×4 grow tent, or 4×5 grow tent )

      Perfect for 5ft x 5ft Grow Spaces: Yield Lab Pro Series 1000W HPS+MH Air Cool Hood Double Ended Complete Grow Light Kit and 600 Watt Advance Spectrum MAX LED Grow Light Bar

      The Yield Lab Pro Series 1000W HPS+MH Air Cool Hood Double Ended Complete Grow Light Kit is all about big coverage and intensity.

      This HPS and MH grow light kit will provide the necessary lumens to up to 6 plants in a 5×5 grow tent through the vegging and flowering stages. The power of this 1000w light is perfect for providing the coverage and depth to reach all of your plants .

      If you’re growing plants in a 5×5 space and you’re looking for an HID grow light, it doesn’t get much better than this HPS and MH light kit.

      HPS and MH Grow Light Specs

      • Wattage : 1000w
      • Lumen Output : 159,200 lumens (HPS bulb); 85,200 lumens (MH bulb)
      • Coverage : 6 plants ( 5×5 grow tent )

      The 600 Watt Advance Spectrum MAX LED Grow Light Bar is one of the best lighting options for 5×5 grow tents and grow rooms.

      You’ll get all the perks of LED lighting, including a wide spectrum of light , huge coverage for 6 plants , and energy conservation . Don’t let its name fool you — though this is a 600w LED, it has an HID equivalency of 1000w. That means intense light and penetration for your plants.

      For maximum coverage and a wide spectrum of light for your plants, this is the LED grow light for the job.

      LED Grow Light Specs

      • Wattage : 600w
      • HID Equivalent : 1000w
      • Max PAR Rating: 855 PPFD at a 12-inch height
      • Coverage : 6 plants (5×5 grow tent)

      For Commercial Growers: Yield Lab Professional Series 120/220v 630w Dual Bulb CMH Open Wing Complete Grow Light Kit and Horticulture Lighting Group 650W Scorpion Diablo Full-Spectrum LED Grow Light

      For growers working with a lot of plants, the Yield Lab Professional Series 120/220v 630w Dual Bulb CMH Open Wing Complete Grow Light Kit will get you huge results.

      This CMH grow light kit’s open wing design allows for a wide, even spread of intense light that will penetrate deep into your plants. That means optimal growth thanks to all that light your plants will be exposed to.

      In addition to giving you bountiful harvests, this kit runs cooler than most standard HPS and MH grow lights. This is a nice bonus since this kit is best used in conjunction with multiple grow lights to cover large spaces in bigger grow tents or commercial grows.

      HPS and MH Grow Light Specs

      • Wattage : 630w (2 bulbs x 315w)
      • Lumen Output : 33,000 lumens per bulb
      • Coverage : 6 to 9 plants (5×5 grow tent or grow area, 6.5 x 6.5 grow tent or grow area)

      If you need great coverage and penetration, the Horticulture Lighting Group 650W Scorpion Diablo Full-Spectrum LED Grow Light will give your plants exactly what they need.

      This LED offers a full spectrum of light perfect for 5×5 to 6.5×6.5 grow areas . Ideal for commercial grows, this light keeps heat at a minimum , so if you’re using multiple lights in a warehouse, you won’t have to worry about intense temperatures.

      Do you need a lot of coverage space for your commercial grow? Look no further than this LED grow light!

      LED Grow Light Specs

      • Wattage : 650w
      • HID Equivalent : 1100w
      • Max PAR Rating: 1900 PPFD at a 12-inch height
      • Coverage : 6 to 10 plants (5×5 grow tent or grow area, 6.5×6.5 grow tent or grow area)

      Best for Beginners: Yield Lab 400W HPS+MH Wing Reflector Grow Light Kit and S180 Advance Spectrum MAX LED Grow Light Kit

      Looking to start small? The Yield Lab 400W HPS+MH Wing Reflector Grow Light Kit is the best HID grow light kit for beginners.

      This kit includes HPS and MH bulbs to help your plants get through all stages of growth. It’s perfect for 1 to 2 plants , though you could potentially squeeze in a third small plant.

      At 400w, you’ll get enough light intensity for a small grow. In addition, priced at under $150, this grow light kit is a great way to get introduced to indoor growing!

      HPS and MH Grow Light Specs

      • Wattage : 400w
      • Lumen Output : 55,000 lumens (HPS bulb); 36,000 lumens (MH bulb)
      • Coverage : 1 to 2 plants ( 2×2 grow tent )

      For beginners or growers who just want to grow 1 or 2 plants at a time, the S180 Advance Spectrum MAX LED Grow Light Kit is an awesome light for small-scale growing.

      You’ll get all the perks that larger LED grow lights offer, but this light is specifically designed for growers who just want to keep things small or who don’t have a lot of space. Whatever the case may be, with this LED grow light you’ll get a full spectrum , deep canopy penetration , and nice intensity .

      If you want solid yields from your small grow, this LED will get the job done with no problem.

      LED Grow Light Specs

      • Wattage : 145w
      • HID Equivalent : 250w
      • Max PAR Rating: 531 PPFD at an 18-inch height
      • Coverage : 1 to 2 plants (2×2 grow tent or smaller grow tents )

      Finding the Right Lights and Intensity for Your Grow Room

      You can’t overlook the importance of light in your grow tent or grow room. Your grow lights make up one of the most important parts of your indoor grow.

      Whether you’re using HID grow lights or LED grow lights, you’ll want to make sure you provide the right amount of intensity and coverage for your plants.

      With the information and tips in this article, you’ll know how to effectively calculate the necessary lighting for your canopy. That way you’ll see rich harvests and have peace of mind knowing that your plants aren’t lacking exactly what they need.

      Editor’s Note: This article was originally published May 7, 2015, and has been updated for accuracy and detail as of April 20210

      June 14, 2021 at 15:33pm

      “Wow, this was extremely helpful! Thanks for putting it in language that a beginner like me can understand.

      Most growers just generalize & tell ya to put all CFL’s about 4″” from the plant regardless of how many watts it is. I never questioned this until now. I also use a 20-watt LED gooseneck lamp for supplemental lighting & was pleasantly surprised to see you included low-wattage LED’s in your explanation.”

      June 14, 2021 at 15:33pm

      “Very good write ,reasonable advice. thanks a lot i got alot of information about out of this alone. “

      June 14, 2021 at 15:33pm

      Yes i ordered a high pressure sodium grow light system its only 150w bc i wanted to try it out at first bc i started a second grow bc my first grow came out horible out of 22 plants i got 5 good ones bc i had cheep led grow lights i axsholy spent 150 dollars on a good 600w led full spectrum grow light in my grow tent and its bringen some of my plants back to life bc i thought when i transplanted one i killed it bc the bottom leavez turned yellow and then brown when i got the good grow light in it seams to be bring some of my plants back to life but for the hps system i ordered i got a 150w one how high over top of ur plants that just poped out of the ground 2 days agi should u hang it can u give tell me like how many inches should it be from the plants to get the best grow im gonna eventually up tge wattage or i might just us the 150w hps kight till they get a good hight and then stick them under my good grow light bcbit pased the cfl i think thats wat its called grow test the led i bought

      June 14, 2021 at 15:33pm

      “Hey so I know this thread hasn’t had activity since ‘19 but I just wanted to throw this out there. My grow space is a 36”x36”x72” space. I’m only going to grow a single plant at a time since my needs are small and based on conversations I’ve had with long lasting reputable seed banks. Based on the banks info the yields are based on 1 meter squared which is 3.26feet so my space is perfect for that; some strains list this measurement and recommend a 600w light to go with it but that seems like over kill. I currently have a single (all-in-one) 150W HPS light but I’m currently debating an upgrade and there are two choices I’ve whittled it down to and wanted to get some in-depth advise. Should I get a second of my current lighting system so I’d have 2 150W HPS or should I go with a single 315W CMH/CDM.
      Climate control isn’t an issue since I have the ability to keep the temp stable between 68-80 degrees Fahrenheit within a 2 degree margin of error and my humidity and ventilation are solid as well as augmented CO2 levels so it really comes down to just the light. Any input would be greatly appreciated and the more the better. Stay safe and best wishes to all.”

      June 14, 2021 at 15:33pm

      “I agree with Aaron.

      If you divide the square footage of the area by 4 square feet per plant, you should get the number of plants that can fit in the area.

      From the above example:
      240 square feet/4 square feet per plant = 60 plants.

      I don’t understand why the area of the canopy is not just the same as the area of the room you’re lighting.”

      June 14, 2021 at 15:33pm

      This is my first attempt to grow using 2 plants with light power of 60 led bulbsafter 40 days they are doing fine do i need other strength lights

      June 14, 2021 at 15:33pm

      The proper distance for the <a href=”””” target=””_blank”” rel=””noopener nofollow””>600w Grow Light Kits would be 14″-25″ away from plants. You can read more about that on our<a href=”””” rel=””noopener”” target=””_blank””> How High Should Your Grow Lights Be Above Your Plants? post.”

      June 14, 2021 at 15:33pm

      We would love to help you out with that for a 10×20 Grow Room you can fit up to 12 mature plants or up to 30 smaller sized plants. However, in regards to the lighting you would need to go with the <a href=”””” target=””_blank”” rel=””noopener nofollow””>1000w Grow Light Kit to get you started. Now if you were looking to go with LED lighting you would need 2x S<a href=”””” target=””_blank”” rel=””noopener nofollow””>810 Advance Spectrum MAX LED Grow Light Panel to equal the lighting that you will need for this size tent of coverage of plants.”

      June 14, 2021 at 15:33pm

      What is the proper distance I should have my 600 watt MH optimized vegetative growth light from my plants that are in vegetative? Also can you change a male plant in to a female that just started to sex?

      June 14, 2021 at 15:33pm

      For the <a href=””×24×60-reflective-grow-tent.html”” target=””_blank”” rel=””noopener nofollow””>Yield Lab 48” x 24” x 60” Reflective Grow Tent this will need at least a <a href=”””” target=””_blank”” rel=””noopener nofollow””>400w Light Kit coverage. Any of our 400w Kits would work best with this selected tent for you.”

      June 14, 2021 at 15:33pm

      What a great question you asked here!
      However, you might want to stay right where you are in regards to the lighting. Due to overkill of the plants if you were to add more lighting in a 4×4 tent it would be to much coverage and heat for the plants. You should be good to go with 960 watt of what you are working with right now.”

      June 14, 2021 at 15:33pm

      How many lights do I need in a 10×12 room? And how many plants can i grow in the 10×12?

      June 14, 2021 at 15:33pm

      No need to worry we got you covered although you were fairly close you were off just a bit. Your total wattage would be 140w in this case 140w would not equal to any light in particular exactly so you would need to get the wattage closes to what you will need. In this case you will go for LED with the <a href=”””” target=””_blank”” rel=””noopener nofollow””>Advance Spectrum MAX S450 LED Grow Light Panel. If you were looking to go with an HID set up then our <a href=”””” target=””_blank”” rel=””noopener nofollow””>400w Grow Light Kits will also get the job done for you.”

      June 14, 2021 at 15:33pm

      We got you covered!
      You’re right, if you were looking to cover 4 plants in a 4×4 area 1000w would be too much coverage for your plants. In a grow room up to 4×4 we would suggest getting the coverage of 600w HID lighting or either and 600w of LED lighting. The 1000w would be too much heat for your plants and can cause serious damage, swap it to 600w of LED and you will be just fine.”

      See also  american burn weed seeds