LED Grow Light Forum

Hi,

Curious if people are keeping the light at 18 to 24" from top of canopy or can it be used closer to the plants without leaf burn/bleaching?

Please let us know if you ran it closer and roughly what height from the canopy you kept it.

Thanks, RKY

Hey Rky,

You know that my girls got way too big. I had to do something to get light down lower... Since the big lean I have had my CLWs at about 12" and my Mag at about 8".

I have seen a fan leaf or two that got too close and bleached a little, but the bud seems to be doing ok at 12"...

But then again, I am just learning and don't know any better...lol

Happy

I have not finished my cabinet yet, damn work getting in my way and it is still to hot to put it in the garage until it cools some. But, this will be good info to know, so I am hoping you get a lots of response.

I will be in my cabinet within the next two weeks.

Look forward to your grow journal Rky!

GR

Took a measuring tape to the canopy and it reads exactly 12" from the tallest top. No ill effects at this point. I think they will grow another 2" Max. Take into consideration my cover area is not ideal and plants get a 1/4 turn every day. This means there is an intense level of light on about a third of the plant.

I've got 4 different strains going, and the light ranges from 12 - 16 inches away from the plant tops...I'm transplanting tomorrow, and plan to adjust their levels a little to get them to be more equal in distance. I haven't noticed any negative impact from the light like bleaching....best of luck man!! ICB..

Hey RKY, I put em at 28-30 inch in veg to help em reach for the light. Flower, I have had em as close as 9 inches without bleaching. try a few different heights daily. It only take a day to see the bleaching, and move up from there, but beware, all strains will be different. peace!

It's true that different conditions and strains will give you different results as far as distance from the top of the canopy goes.

However, the closer the light is, the smaller the effective footprint (but more intense) and the further away it is the less intense the light is (with a larger footprint) and that's true of any lighting source.

I am able to keep the ss400 within 8-9" without light bleaching but there is always a fan at the canopy to cool things down, I always think about it as a light source and consider the distance from the sun to earth it's a long ways so when the sun hits the top of your plant there is not much difference in intensity from top to bottom but if your distance from your light source is only a total of 3 foot then traveling a few inches is like moving the sun hundreds of thousands of miles away from earth.After all, light can only travel so far and penetrate so far before it looses intensity.

Thanks for everybody's help.

The main reason I asked is that I was keeping it at 18" during bloom for my last grow. I had enough issues that I didn't want light burn to be another.

But if we can safely run it at 12" or less (8 to 9" in some cases), that extra 6" of possible canopy penetration would be most helpful in my next harvest as far as yield.

Thanks again!