Led height and watts

Jan 13, 2020
Reaction score
So i am kinda new to autos and led lights. Im running 8 plants (mix of mephisto freebees) in a 5x5 tent under three 240watt boards. They are at about 3 weeks and the 4 (that the cat didn't dig up:doh:) are looking good. But the top leaf tips are getting bleached on one plant and another one has the look of a plant almost is to the point of too much light. I have bumped the lights up equally about 10 watts a day tell i got to around 400w between the 3 lights. I tried to keep the lights about 30" to begin with but assumed that as they got bigger they would be able to get closer to the lights.

My question for all you experienced led auto growers is: how far away and at what wattage do you keep your lights at different stages of growth?

*Fyi i turned the dimmers back to 100w per board and move the lights up a few inches to get them at 30" above the tops of the bigger plants.

Last edited:
@ManicOrganic :welcome:Welcome to AFN:welcome:It is complicated, the number you are looking for is the DLI daylight integral. That is a measure of the usable light the plant gets in a day. 42 to 50 is good. Google DLI Calculator and you can play with the numbers. Now go find the PPFD map for your lights and those numbers will make new sense to you. Remember this is going to be ballpark stuff not like using an expensive meter :rofl:
Thanks for the reply man. I read for about an hour and watched a couple videos on the subject of dli and ppfd mapping and while i learned alot i still felt it was above my head. We are doing good at 120 watts per light and about 25-30 inch above the tops. Going to increase the watts as we come into flowering and go at a bit slower rate.