Led grow lights - how to select

Oh Yea. The options are incredible when you really start to dig into it and compounded when you fancy the DIY aspect.

At the end of the day, it comes down to what you want to accomplish.

When I first started to really dive into gardening, I read a lot and shared some thoughts with him, his reply was, “Don’t reinvent the wheel”. I thought to myself, Yea, he is right. But about 2 weeks later, I realized that his words were genuine, not meant to be rude, they were incredibly myopic and honestly, lazy. That comment continues to drive my learning and experimenting. Sure, none of are likely to argue that a circular object, a wheel in this case, is likely the most effective shape, it doesn’t mean that the rest of parts are effective. If someone next went on to.develops spokes to reduce rotating mass, or bearings to reduce the wear on the axles, etc etc, we’d be in bad shape.

My point is that while we all agree lighting in the ~380-~760 (just picked some rough numbers) play a huge role in plant growth and development, there are an incredible amount of ways to provide that light in various amounts and intensities etc.

My feeling is that so long as we use something that is a known high quality item, individual parts or whole fixtures, by brands that are known to understand the field and desired outcomes and openly disclose their metrics, we’ll likely not have an issue.


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This is my plan at some point. How many hours do you run them?

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I’ve gone on many led forums. most of the growers on there agree that most mid priced leds that have many and good reviews are just as good as the higher priced commercial ones as far as light produced. where they mostly differ is in how long before the quality of light they emit starts to degrade. viparspectras have a 3 year warentty and generally go about 6 yrs. before you start getting poorer results. the high end ones might last 10yrs. i only use mine from nov. to april here so they may last longer. my king plus 1200w led is 5 yrs old and still working well but not as bright as my 3 yr. old 600w viparspectras are.

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Depends on your application, but typically:

Vegetative (growth) - 16-18 On, 6-8 Off
Flowering Stage - 12 On, 12 Off.

For my starts, 16/8 has worked very well.


18 on 6 off. you want veggies fast, leave them on 24hrs.

LED Grow Lights 2020 - White LEDs; Household LED Bulbs and LED Tubes?

12-22-2019, 07:28 PM

Two decades of Academic Research clearly indicates that spectrum and intensity dictate the growth and shape (morphology) of a plant, with broad / wide spectrum resulting in healthiest growth and production. The “Limiting Factor” initially with White LEDs (WLEDs) as Sole Sourse Lights (SSL) was Low Electrical Efficiency, which was overcome with the advent of the current generation of WLEDs that produce over 100 Lumens per Watt (L/W). Following are two (2) lengthy but informative interviews with Academic Agricultural Lighting Researchers and this article; What Is The Best Grow Light Spectrum?

Household LED Bulbs (UL and or DLC Listed) can provide adequate PAR and EPAR / PBAR (light) contrary to "Perpetuated Grow Light Misinformation / Myths" . 2700K and 3000K LED bulbs rated 80 or more CRI can provide better PAR spectrum than Red / Blue LEDs and HPS, the Agricultural Industy incumbent grow light, while 4000K and 5000k LEDs can provide better spectrum than Metal Halide and Fluorescent. Standard 100 Watt Equivalent LED light bulbs labeled as 1600 Lumens per 15 watts (Actual Measured Output) produces over 1700 Lumens with the opaque globes removed, resulting in at least 1.8 PPF efficiency and 4 foot T8 LED tubes labeled as 2200 Lumens per 17 watts are at least 1.9 PPF efficiency (1000 Lumens = or ~ 15 PPF).


Light Source PPF (Efficiency)
1000W DE HPS 1.7
400W HPS 1.5
400W MH HID 1.4
315W CMH 1.5
Fluorescent 0.9
WLEDs (100 L/W) 1.5
WLEDs (120 L/W) 1.8
WLEDs (130 L/W) 1.9




Commercial White LED Grow Lights… 2020


This information was posted by a trusted member in Ourfigs, he is really knowledgeable about this and other topics. I don’t attempt to get credit, I just wanted to share the information.


i use to use a 4 way spreader and use household leds with the domes removed, to grow with. id use 2 3000k and 2 5000k 15w. they grew pretty good but didn’t have much coverage area. i now have 2 viparspectra 600w leds that cover a 4’ x 7.5’ area. they grow very well for the price.

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I am confused about what LEDs are acceptable for starting seedlings.

The above quote sounds to me like regular white LEDs, 5000K blue light range can be used for starting seeds. Am I understanding this correctly?

For seed starting (vegetative growth) cool white is preferable. But if you use warm white its not a big deal either. The total lumens output is 10X more important for young plants.


yes, and 2700K is preferable for flowering/ fruiting. most quality leds have a switch to go from veg to bloom. my viparspectra 900w does and grows well.

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I apologize for the questions! I have re-read this several times and read the articles that are linked. It still feels like it is Greek to me! :confused::persevere: I am really slow when it comes to understanding LEDs apparently. Requirements in lumens, wavelength, CRI, figuring out the output area each strip or light will cover, distance between plants and LEDs (vs plants and fluorescents), etc.

I really only need light for vegetative growth at this point. Just starting seeds, not trying to get anything to flower.
I have 3 shelf areas that are 2’x4’ each. The bottom 2 shelves are spaced 24" apart for height, and the top shelf has 14".
We were going to buy LED full spectrum grow light strips, 4 for each shelf, spaced equidistant. I don’t know the specs on them, my husband picked them out. Just found out they are back-ordered so we are starting all over again.

I want to do this the cheapest and most effective way possible. I can’t afford anything fancy. My husband was going to mount the strips, connect to power source, etc. Buying individual strips looked like this would be the cheapest way to go and still get decent coverage area.
Those Viparspectra look great but are way out of my price range. :confused:
Any advice on what would be sufficient for this area in terms of lumens, spectrum, etc?

i used regular 5000k 100w equivalent led light bulbs with the covers taken off. get a 4 way splitter screwed into a regular socket and hang them above your plants. also if your husband is good at electrical wiring, he could daisy chain them in rows under the shelves or make a fixture using some sheet metal so the light coverage is even. this is by far the easiest cheapest way. i don’t know what thread but someone on here posted a pic of one they made like that. t5 grow lights with 5000k bulbs are also a good cheap option for growing seedlings.


Thanks so much. That helps a lot! I will forward your advice to my husband. I am sure glad he understands electrical and construction. I can grow stuff, he can build stuff!

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Here’s one I did this year. The light fixture was about $15 and the bulbs were around $10. The light chain is those outdoor string lights that just hold regular bulbs.The cheapest bulbs I could find was from Menards. They’re the 15 watt/100 watt equivalent. Just give the globe a good twist and pop it off. The nice thing about this is you can mix the spectrum or change it if you want. I missed it. Depending on what you’re trying to grow a couple shop lights with LED bulbs or LED shoplight with built in lights work well for seed starting. They’re around $20-$25 each, but I would put two per shelf right next to the plants.


Thanks Travis. I hadn’t considered using individual bulbs. I didn’t think they would cast enough light - be able to cover the area completely, I mean. I like the idea of buying different spectrum bulbs to get a mix that way.

I started out this process thinking if we went the LED shop light route, we would need 2 per shelf, and call it good. They come in approx. 4’ lengths, so that works with our shelves. 5000K bright white, 3200 lumens, CRI 80, for $15 each at Menards looked like a good deal to me. The more I read, I became concerned the wavelength wouldn’t be good enough to grow healthy plants.

Then we thought we could maybe get better lights (full spectrum grow) for similar price if we went with LED strip lights and ‘constructed’ them to fit what we needed. It looked like we could get 4 strips for $30-40. Those ended up being out of stock.

I really appreciate your input. All of this information helps a bunch!! We should be able to make a decision and get some darn lights ordered already!

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I forgot to ask - How long and how wide are your shelves in the picture?
And what are your containers made of?

The shop lights work just fine for starting seeds. Some plants like a little more light than others. Like peppers and tomatoes I usually make sure and put them under my stronger lights. For things like cabbage and broccoli I don’t worry about it as much. I’m probably going to end up doing a rotation this year because I’m running out of space and don’t want to buy more lights!

Those are the standard wire racks you can get at Menards or Lowes. I think they’re 4’ by about 20". They fit 4 of the 1020 trays about perfectly which is why I really like them. If you watch Lowes has sales on them a few times a year. They’re around $50 on sale.

The light bulbs are rated at 1600 lumen each so that’s 16,000 lumen per shelf. I know you’re not supposed to measure light for plants with lumens, but it makes it easy to compare the standard lights IMO.

This is my third year starting plants with LED and they’ve always been healthy. I have some that are 3000k and some that are more around 6000k. They both grow fine. Peppers seem to like to put on bloom early with the 3000k. I’m not trying to grow year round, once they go outside they all need to get adjusted to the sun anyway and take off.

I’ve also made my own with the strips I listed above. Those are good too. They put off a lot of heat and will sunburn the plants if they too close. I’ve been running them half power this year and it’s going fine so far.

The containers are just plastic 1020 trays. The pots are ones that @Barkslip recommended. I’m loving them so far! If you need a tray for the whole shelf these fit perfectly. They’re out of stock now though. Giant Garden Tray The Giant Plus ones do not fit the wire shelves though.


Good. I’m glad you’re liking them. I’m liking them, too.

I had a fella say his fig roots were going into each container and it made wonder if another variety could pop up later because of. I don’t know? Otherwise, I think he liked them too. The roots they make are superior.


My peppers are doing that too. Their roots aren’t quite as intrusive as a fig though. I think you just need to space them out so they can air prune better. I’m trying to make sure they dry out plenty to almost the point of wilting before watering again. That is seeming to help dry up the roots.