Have a look at this article… I found it pretty interesting, as it breaks it down in the way you’re asking:
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Ok, back to the OP’s question (because I have a related question). We can find PPF ratings for reputable LED light msg’s. What about a 4-light or 8-light 4’ T5 HO fixture? Is there an equivalent PPF known?
Would help in selecting LEDs and deciding if I’m better off just buying Old T5’s on craigslist (1/4 the cost of reputable LEDs).
PlantGrowthRequirements.pdf (2.9 MB)
Just copying and pasting the PDF into the thread. protect against links going dead.
At this point I really do not think cheap LED’s are so inferior to effect any or our results. Say you prove the cheap LED system was 20% less powerful then advertised. When the cheap one costs 1/5 the the certified version you can simply get two cheap ones and still be a head by 3/5+
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Thanks for doing that.
I think some of the concerns surrounding the cheap LEDs and just replacing when they fail are waste and inability to recycle, strobe effect, and potential safety issues, due to not being properly listed. That last one to me is key, when you are watering close to the light. But, I get your point.
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I’ve been growing seedlings and some carnivorous plants and orchids under various inexpensive T8 LED type lights by companies like Monios, Brillihood and some others that were replacement bulbs to go in old fluorescent fixtures that had the ballasts removed. They’ve all been okay, but really just okay, and I always feel like I’m seeing some foliar issues because of some of the light they are missing.
The biggest issue is with tomato rootstocks for grafting that can develop edema to the point the plants are deformed or even killed when it gets really bad. There is research showing this is the result of the lack of UV (and to some degree IR) in a lot of LED lighting. I’m trying some with more varied LEDs this year that include some IR:
But UV seems essential as well, particularly for keeping the internodal length down which you want in seedlings, so what about adding a few of these in the mix of lights over my shelves:
Anyone tried adding some UV like this?
if you want to buy good led grow lights, check out horticulture lighting group. i just built this new light yesterday using led boards i bought from them on sale. it is bright AF, max power is about 650w but I’m running it at its lowest power right now, around 300w.
MEAN WELL USA Inc. / HLG-320H-54A x 2 = $233
QB96 Elite V2 Engine × 4 = $252
24x30 sheet scrap aluminum = $10
20ft white extension cord = $14
Misc parts and wire approx $20
Total= $529
if you want to light shelves, i recommends bridgelux EB strips for DIY, 3000 to 4500k with adjustable meanwell drivers
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the IR issue can be resolved by increasing your ambient temps to 80 to 85f during the day, also issues with calcium and magnesium are common when growing under led, you can buy fertilizers designed to resolve this issue.
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if you want to learn about growing under led, the marijuana guys know their shit for sure, when you grow plants that sell for hundreds of $ / oz you need to know what you are doing! haha
if you need led strips for shelving these are what i would recommend, they come in 1, 2 and 4ft lengths.
https://www.digikey.com/en/products/detail/bridgelux/BXEB-L1120Z-35E4000-C-B3/7907661
i can also give some recommendations about drivers if anyone is wanting to diy a light
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I agree with you to a point. However, I’m interested in products that will last as long as possible. I bought an LED unit that is about twice as much as cheaper units, but it should last me 30-50 years at the rated life for the amount I’ll be using it. I wouldn’t expect a unit that costs half as much to last anywhere close to half as long.
Can we just stop and remark on equipment that will last 15-25 when you buy junk vs 30-50 years.
I do not know how much more efficient LED’s can get but I can imagine changing the equipment out a few times over the years not because of failure just because newer better and or wanting to achieve different spectrums as the research improves.
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Yes, there is definitely something to that. If I were to use this more constantly and to fruit plants or for commercial purposes, I’d probably care more. But I’d also probably be hitting the design lifespan in 5-10 years. I’m just using it for seed starting and maybe some fig cuttings, so it will continue to be good enough for my purposes. All that being said, I wouldn’t be surprised if something goes on it just due to aging before I run it for 54,000 hours.
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nice thing about diy is if a component breaks, it can be replaced without trashing the whole light… meanwell hlg drivers come with 7yr factory warranty which is pretty good
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if the manufactures don’t give you REAL data, their lights are likely junk, ppf, ppfd, par, actual electricity draw, lumens/w are important to consider. when they tell you equivalent to xxx light, that’s a red flag if they don’t also offer you REAL data. LED CAN be more efficient than even the best HID fixtures, but often that isn’t the case, it all depends on the components, there are many LED lights that are actually less efficient than comparable HID fixtures. if you aren’t paying about 2x as much for an actually comparable LED to HID, you aren’t getting a quality light. GOOD led costs MORE, but will use about 30% less energy and still put out 90% or more of its original photons 10 years later. when you factor in electricity costs and bulb replacements, over that time span, good led ends up costing SIGNIFICANTLY less than other lights…
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I grow plants from seed/cutting through to harvest using bathroom vanity light bars and off the self led light bulbs. Take the plastic dome off the bulbs. You want about 20-35w/sqft for indoor gardening. when looking at the wattage, go by the actual power drawn, not the brightness equivalent. At 30-35w/sqft, even peppers and tomatoes would grow well. I just don’t think I can/should post pics my plants here 
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ive done whole grows under those bulbs. i pull the domes off. man, they’re bright. a friend of mine was just getting into growing and didnt have much money so i set him up with 2 socket lights each with a 4-way splitter each with a 150w equivalent bulb. he grew a very nice tree from that set up. 
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I’ve been running these just over a year now, haven’t had to replace a bulb yet. I’m about to start some peppers to try hydro for the indoor garden, just to add some variety. maybe take some mature cuttings to put outdoors instead of just seeds for the outdoor garden.
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here’s the kicker, these strips you can run directly from a dc power source, so you don’t need to buy fixtures to install them in. they are light and cheap but best of all, unless your electricity is free, you’ll save a ton of money over time…
https://www.digikey.com/en/products/detail/bridgelux/BXEB-L1120Z-35E4000-C-B3/7907661
175 lumens / watt, 4800 lumens total, $8.50 each.
those bulbs are 800 lumens consuming 9 watts = 90 lumen / watt, so you are getting 50% the efficiency for the same amount of electricity. you need 6 of those bulbs to produce the same amount of light as one EB strip. i don’t know the cost of those bulbs, but id guess, with the fixtures figured in, you could use led strips for about the same price. if you are only using them a few months every year maybe efficiency isn’t a big deal, but if you run them most of the year, like i do, it really pays to go the more efficient route. also you can push the strips a lot harder than the recommended power, but then you need to add some aluminum plate to absorb the extra heat.
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I need to add lights to fluorescents that I have for seed starting. Can I just buy LED shop light fixtures from HD or somewhere? or maybe LED tubes for old fixtures. I need to grow out trees til April, I’ve got an enclosure created from gridwall panels covered with reflective mylar sheets. I can add to that as I need for space, but have no idea about lights that don’t require too much thought or money. I know it’s usually one or the other.
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id love to divulge but i had a bad scare with electricity when i was young so dont trust myself assembling my own lights. id be willing to pay for one like yours. could sweeten the deal with a generous donation of my special seed collections.
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