How close can a 600 watt led be moved above the plant?

Thiers alot of poeple who believes LEDs can be put really close to the plant and believe thats how u get the most out of it. However when ever i do that in vegg the plants get bleach white. And if i do that in flower the buds taste like crap kinda like smoking crushed medicine and nothing like the actual strain. Now i have my LEDs as high as i can to promote stretch during 12/12 and garantees no bleaching. When stretching stops how close can my 600 watter led be with out damaging the buds? Last time had it 3-4 inches away and at 1 point let the buds touch the leds creating ugly nasty buds.

I'm far from an expert on growing with LEDs, but you are trying to promote stretch? Wow, if only I could have that problem. Anyways, I'd just back off on the height a little until you get normal green growth and keep that height for the remainder of your grow. Obviously, since LED canopy penetration is not optimal, you'll have to strike a happy balance between getting good intensity, potentially bleaching, and getting a bit too much stretch/airy buds. I'd imagine that to do it right you'll probably need to adjust the light height almost daily during rapid veg and probably until the end of stretch. Unfortunately, I think this is the price you pay for having extremely intense PAR without a ton of penetrating power. If you haven't LST'd/topped/bent/tied down you might be able to do that so you can get better penetration without scorching a main cola or two.

-There are other examples of people on here with photobleaching issues while using LEDs, not sure what they did. Just goes to show you there is a such a thing as too much PAR.

Good luck!

Well my plants are 2 months vegg from seed super cropped and lower stressed train, im trying to get the secondary braches to be 1-2 feet tall each and thier are 14-20 branches each with alternating nodes like to the 4th or 5th node each branch. Im also growing pure indicas so a little stretch would be nice to help fill the space. But im wondering how close is too close with out sacraficeing bud qaulity?

Ive never used LED before but that is a hard question to answer ha ha. I wouldnt promote too much strechin either, thats how you get airy fluffly nuggz like the guy above said. But i dont think having the light too close really sacrifices bud quality per say, i mean if the LED's are emitting a lot of heat for some reason that might effect the plant but LED's are cool right?. If the plants are under stress and u keep moving the light up and down up and down up and down, it will stress the plant too. plants like a reliable schedule . I would maybe go 12 inches away and leave it like that for a week or 2 and see how they look. then slowy move closer after the plants stabilize, like maybe an inch every 2 days . hope this helps bro

I like the way you think, dope. Although I'll pretend you didn't just call me guy. I totally agree though, as long as heat is not your issue you're not going to kill your bud. But, if it's white from bleaching then that nug at least is probably gonna smoke like cardboard. Too much light/UV will kill THC so I'd imagine even an LED photo-bleaching chlorophyll would also photobleach cannabinoids/terpenoids. (You'd probably lose flavor and potency at the tippy top)

Back to the question, you'll need to find out by trial and error, start at 6-12 inches and adjust/check daily. (All assuming you can be there once a day to scope things out.)

lisa L said:

I like the way you think, dope. Although I'll pretend you didn't just call me guy. I totally agree though, as long as heat is not your issue you're not going to kill your bud. But, if it's white from bleaching then that nug at least is probably gonna smoke like cardboard. Too much light/UV will kill THC so I'd imagine even an LED photo-bleaching chlorophyll would also photobleach cannabinoids/terpenoids. (You'd probably lose flavor and potency at the tippy top)

Back to the question, you'll need to find out by trial and error, start at 6-12 inches and adjust/check daily. (All assuming you can be there once a day to scope things out.)

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ha ha sorry chick. Im used to replying to guys ha ha! anyways yeah dude start off at a medium height and just watch how the plants react.

So how was your yield with the wattage of LED lights you grew with? I looked into building my own but once I priced out higher wattage LEDs, I found that it woudl have cost me upwards of $500 anyways.--I just still don't know about the price/gram using an LED. (Not just for electricity but for the start-up cost, as well.)
-I've had nothing but good things to say about the two 400w HPS's I built from kits online for less than $150. I managed to also score some pulse-metal halides from a warehouse that shut down in the area and sold off its stuff by auction. I don't even have cooled reflectors and everything has been fine, thus far.

One thing i found that a myth is LED stretch weed, well mabe a shitty UFO or a shitty side panel. When you go big with LED you will find the plants recieving so much blue light that they dont feel a need to stretch i mean thier happy with lots of nodes and alternating nodes. As for yield just like an HPS they are strain based, i grow very low yielding strains like kush and i average 1 Oz a plant with a 1 month vegg.

I never thought they would stretch as long as they had a good composition of blue LEDs, but I've always worried about their penetration over other light methods.--Interesting post, though.

Im theory the reason for shitty penetration is becuase low watts are being used i mean common a 90 watt HPS would penetrate as shitty as a 90 watt UFO. The only problem with LEds are 1. The angles of your bulbs some are provide huge coverage but shitty penetration. Some like mine have superior penetration hence why i have lack of stretch, but my coverage is real shitty so the way you grow depends on the type of angle your bulbs are at. since i have suoerior penetration i grow 3 large plants stack underneath below the Led. Im no pro led grower im still learning everyday and getting better. now that i change my method hoping for 3 Oz a plant with kush.