Help with lighting setup?

I have 4 600w leds that draw about 550 actual watts and a 315 cmh that draws 300w in a 4.5x4.5 grow tent.
Is this too much light? How high should I have them?
I was experiencing light burn I think so I raised them, im having nute problems so that could be why I guess. Thanks



I don’t think it’s too much light. Probably wouldn’t have them any closer than 18", maybe even a little further. Just need to make sure the plants are hardened off properly.

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I just did an experiment to see what would happen if there was too much light, kind of what you are doing. My leaves look similar to yours. I decided that my plants need extra calcium to keep up with the demands for additional nutrients caused by “too much light”. I immediately cut back on light, started cal-mag, a cal-mag foliar spray, and finally just calcium. Seems to have stopped the progression.

Am gradually increasing the light again but with extra heavy feedings of cal-mag. Going to see if it works. You can join me in the experiment.


i would be interested what you find out

Yours are getting burned almost? I’m get rust spots popping up and leaves are almost burning in half, I find new leaves on the ground. There trying to shade each other all the fan leaves moving in on each other?

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There is a general dullness and slight discoloration of leaves that extend throughout the canopy, even the heavily shaded ones.

This is as bad as I could find without digging through the entire plant. There is progressive spotting and dying of leaf tips. This leaf was from the middle of the canopy

I should add that this is a Goldleaf and I’ve was burned by this on my first grow, but I’m on week 6 of flower and some of this MAY BE Goldleaf genetics.

i skipped one feeding of calmag and saw it show up on my leaves in a few says. i believe the light does cause them to really hog the cal mg

I’ve continued cal-mag and calcium with every feeding, but am convinced that some of my discoloration is caused by being a Goldleaf and just 2-3 weeks from harvest. My buds look like they are doing well. I also cut back to 460 watts and am leaving it there.

I have some seedlings started and when I defoliate them in 6 weeks or so I’m going to try 3-4 ways of cloning, making a crap load of clones, and try my first SOG in the “Super bright 3x3 tent”. The experiment will continue.


My yellowing has progressed, yet the leaves aren’t dying, that’s why I think some of it is Goldleaf genetics.

Mine were dieing under the canopy too. After some research I added up my npk and it was 4-3-11 in veg. Iv now tried to correct the problem because I think mine is a potassium toxicity and nitrogen deficiency. I went to 9-3-5.5 to see if it stops yellowing, burning ends, burn spots and wilting. Also what makes me suspect potassium toxicity is the top growth is really skinny and growing slowly

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Mr Grower-
How close are your lights to the canopy? Burnt tips is usually a sign of nute burn. @rookiebudddzz spots on your leaves is sometimes a calmag problem. Yellowing
can be a number of things- over/under watering, nitrogen deficiency. Mr Grower you might want to do a flush or water only for a couple of times. Rookie add some cal mag and see what effect that has. Just general thoughts, hope it helps.