Household LEDs???

[Spanky]

Hello. I am hoping to start a discussion about the use of household LEDs. LED grow lights are so expensive and CFLs are becomingg scarce.

I recently read a post from someone who cuts off part of the plastic bulb on regular LED bulbs...the kind you would screw into any lamp or light fixture...and uses them as grow lights.

I recently bought some 4ft LED shop lights for use in the garage and basement. They were only $25 each. Some are 4000k and some are 5000k. 120 watt equivalent.

None of the manufactures recommend a height from plant as they aren't intended for plants! How would one decide the best height with any household LED?

How would one decide how much light is enough? If I were to use these shop lights, they are so bright that I am not sure more than one would be needed over a single plant. It seems like hanging more would just be a waste. Would it be wise to hang one overhead and add some traditional bulb types around the outside of the plant?

What are the sysmptoms one would expect to see from LED lights too close to the plant?

It would be great to hear from folks with some experience with this method.

[Waltermelon]

To find out how much light is enough you would need to do a lot of moving watching and measuring. Or you could buy a $500 quantum meter.
Yeah it will work. But instead of all that work cutting, measuring, moving, putting things together, why not just spend $100 and get something you know works? My bloomspect 600 costs around $120 and puts out 1300 ppfd at 18" and covers around 2x2 feet comfortablely.

[Chefbjy]

Lighting set ups aren't very expensive anymore. Small lights like CFLs and LEDs are fine for seedlings. If you don't know about LEDs I would recommend a mh/hps. They are great for beginners.

[Spanky]

Thanks guys. I have a Mars Led supplemented by CFLs. I don't really want to get into anything thing that runs hotter, as that will require more investment in air handling and cooling.

I was just wanting to hear from folks who are experimenting with household LEDs as a different method of lighting. I know there are other....and better....setups, but this one is of interest to me right now. I already own lots of sockets.

Maybe I am the only one with this interest?

[DoctorJohnson]

I'm the guy with the cut off light bulbs. A "120-watt equivalent" shop light should be about 18 actual watts or so and roughly 1600 lumens. Spread out over four feet that's not going to be very intense right at the surface, so you should be able to (and will want to) place your shop lights right down close to the plants, just a few inches away, ideally.

If your plants aren't spread out over four feet, you're going to have a lot of wasted lumens, so do try to line them up right under the lights.

Symptoms of lights too close are typically the serrated "teeth" of the leaves starting to scallop if they are too warm, and then the whole leaf starting to curl inward if it's more serious. A fan can help with that.
I really doubt if you'll get actual light burn unless the leaves grow right up into the LEDs, but you'll recognize it when you see it--it kills the leaf tissue.

It's fun to experiment with different lights. I'm still using my cut-off LED light bulbs for one-plant grows and they work great, but I agree with some of the other posters that there are good LED grow lights out there now for under $100. Me, I'm not buying new lights until the incredibly fast evolution slows down a little. I'm pretty sure that in a couple of years a light you pay $100 for today will be selling for half that, and some of the remaining questions about ideal spectrum will be figured out.

[Spanky]

What wattage are your led round bulbs? How many do you use for your one plant grows? How close to the plant to you keep them? Do you use them in flower as well?

I wasn't planning to use the shop lights because I thought they weren't enough watts. Do you think they are? What if I could hang two parallel to each other down close to the plant? Do you think that would be enough light?

I am also confused about something and maybe you can help. Why do led grow light manufacturers suggest a much longer distance from the plant than what you are suggesting? Is it because the household LEDs have so much less wattage?

Thanks!

[DoctorJohnson]

> What wattage are your led round bulbs?
They're a mixed bunch, but about 100-watt equivalent, maybe 15 watts actual?
> How many do you use for your one plant grows?
I have nine on one plant right now, but it's carefully SCROG'd to maximize the efficiency, and I could easily use a lot more.
> How close to the plant to you keep them?
As close as possible. A few inches. BTW they also have aluminum cone reflectors.
> Do you use them in flower as well?
They're all I use for the whole grow.
> I wasn't planning to use the shop lights because I thought they weren't enough watts. Do you think they are?
I think the key thing is concentrating what little light you have on a small area. You focus the light, keep it close, and grow a small plant. A 4' light is going to spread those watts out a lot more, so they will work less well. Basically, each of my lights is illuminating a circle about 6" in diameter right now to give me about 30,000 lux or so. When the plant is full size, each light will have to illuminate 65 square inches (1/9 of a 2x2 tent) which is far from ideal.
> What if I could hang two parallel to each other down close to the plant? Do you think that would be enough light?
No.
> I am also confused about something and maybe you can help. Why do led grow light manufacturers suggest a much longer distance from the plant than what you are suggesting? Is it because the household LEDs have so much less wattage?
The LEDs in LED grow lights are both powerful (about 5 watts each--that's a lot--even though they usually only power them at half that to extend life) and they are lensed. So the light is focused in about 120 degree cone if I remember correctly. A powerful LED focused with a lens on a small area can scorch a plant!

I'm using the lights that I bought to experiment with (and a bunch of lights from around the house as well, which I have replaced with incandescents during the grow). It's fun to see how much you can get out of a limited setup. Last time I grew a dwarf and it was super sticky, but it was also really small.

I do agree with the folks here who have recommended a small HPS or metal halide or an 300 (or better 450) watt LED grow light. It's simpler and easier and ultimately cheaper, I think. I have nine sockets and nine cords. That's a lot of stuff to deal with (though it looks kind of cool--almost like a chandelier).

[Spanky]

Thanks for the info!

[Jordann]

I do exactly what you're asking about. They stay about 6 inch away from the plants. And only supplement the corners I use 23 watt actual bulbs. I have 12 of those in my 4x4. Around 275 watt actual draw. And I say this again. Only supplemental don't know about growing full cycle with them. I would use like 30 or 40 of them in my 4x4 and just keep adding and adding and so forth. They will grow plants though.

[Bengfan]

A couple of years ago I bought a bunch of those ceramic light fixture sockets and mounted them butt to butt on thick industrial cookie sheets. That spread ended up being about every 4". I cut the diffusers off of bulbs ( 2700k with a couple 5000k for flower and 5000k with a couple 2700k for veg.) and grew two plants in an approximate 2x3 closet. I had a very decent yield of about 7 ounces. The bud was pretty hard and the smoke was very good. It was a surprising experiment with a happy end and proved to me at least that it can be done. Good luck!