LED under plants , someone dooo it!

Hi. Because LED are so damn bright, don't put out much heat etc, I think it's time for someone to try a few under the canopy facing up.
I've noticed they are bright enough that you can see through the first leaves it hits.
Wonder if there is any photosynthesis efficiency data from the light being underneath.
Say goodbye to double ended. And hello to double penetration LED style.

Apologies if shit doesn't want to be looked into.
Just throwing out another stoner idea.
If no ones game. I will in about 6 months.lol

Haven't tried leds yet, but have been using 2 x 85 watt cfls under canopy for quite awhile...
With good success!

Plants have much less pigments in the bottom of the leaves. So they deal with light coming from below much less efficiently.

Intra canopy lighting is used however, but that is still aimed at the top of the leaves. Just a bit lower down on the plant.

When a plant is growing outside in sunlight, does it get light at the bottom of the plant?

Same answer as to whether it is beneficial to also do it indoors.

FYI, pretty much anything green in color on a plant will absorb light for photosynthesis. An easy rule to follow - If it is green, light it up.

That's why leaves are more green on top and less so on the bottom. More photosynthesis when the light hits the top, mostly warming up when it hits the bottom.

Here was my first attempt at intra/lower canopy lighting. on paper I've revised this design a bit but since moving I have yet to start my grow up again so I haven't actually built version 2 yet. the pvc 'pole light' in the below pic - i call them bud sabers.

http://imgur.com/EH219DU

Was trying to grow 9 plants in a 3x3 space (standard 3x3 7" deep flood table). my thought was i would need some form of light between each bucket as i was going to be packing them in pretty close together and not trying to keep them as short as possible so the lower branches would be fairly starved for light. i figured the 5630s put out quite a bit of light and this might add enough light down low to make a difference.

some things conspired and the grow in the pic didn't go as planned causing me to lose a few plants (stupid males ...) so i didn't really get much useful data from the grow. these bud sabers are extremely bright despite not looking all that bright in the pic. my revised design will be much shorter and instead of 3/4" PVC I will be using at least 1 1/2" aluminum pipe for the thermal capacity as well as superior heat transfer. These 5630 LEDs do heat up and when they do they lose a bit of light output and the adhesive breaks down. My hope is the aluminum pipe holds and transfers heat better. With the shorter thicker pipe I should be able to drive the same amount of 5630s as in this pic off a 100W 12v supply and have enough power left over for a 12v PC style blower to mount on the top of the pipe - drawing air from just above the hydroton in my flood/drain aquaponics. so drawing nice cool air up/through the tube and exhausting it up above the canopy.

should be starting my grow again soon, this time with 3 DIY lightbars using 9 gen 6 v29s. I'll have 750w of 4000K v29s and then will use the bud sabers @3500K once the canopy fills out and the plants get enough height. Since I'll be doing 9 buckets in a 3x3 grid my experiment will have the bud sabers on one side of the 3x3 and I'll see if those plants produce more than the plants on the other side. the middle row then in theory should also bulk up more on the bud saber side.

worst case nothing 'good' occurs and i spent $100 on 5630s and power supplies for nothing - but learned something in the process. Once i get going again I'll do a journal if anyone is interested.

Was thinking the LED advantage of under canopy would be narrow lens' for extra leaf penetration. A lot less wastage than a dude I know who used to put a reflector and hps upside down a well as less dangerous

If you look from the top down towards the canopy it's pretty much closed. Narrow beam angles would make it harder to penetrate the canopy. I found it easier to get more penetration by getting the lights closer to the canopy and using the wide beam angles of the COBs. the light then slips under the leaves.


In greenhouses they put things resembling light strips in between the plants.

I think someone has actually done this with a 100w smd light strip wrapped around the inside and lid of a trash can lol, the damn think make an ounce of bud too haha. Its somewhere on this forum

SPLFreak808 said:

I think someone has actually done this with a 100w smd light strip wrapped around the inside and lid of a trash can lol, the damn think make an ounce of bud too haha. Its somewhere on this forum

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google space buckets, i've seen a few tsimilar to what you describe.

Yeah, those look cool. Although I always wonder how they keep the plants small enough to fit in those buckets.

wietefras said:

Yeah, those look cool. Although I always wonder how they keep the plants small enough to fit in those buckets.

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well one of the guys in that community uses blue light saturation directly focused on the stem of the plant. the blue light slows the growth of the plant in the vertical while allowing all the branches to grow normally. forget that user's name but he has done some cool stuff with cannabis and pole beans.

i haven't done any space buckets yet but plan on doing 2 using 30 gallon drums for mothers. should be a lot simpler with 30 gallon drums from a maintenance stand point.

Indeed, I saw an article on that blue light trick recently on GrowWeedEasy. They called Selective Light Training.

I run 3000k led tubes for side lighting during flowering, does that count?

wietefras said:

Indeed, I saw an article on that blue light trick recently on GrowWeedEasy. They called Selective Light Training.

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Kevin Folta - land grant scientist - talks about selective light training during a podcast with Joe Rogan. For anyone interested .