Since this IS a light thread, I'd like to share that I just took possession of a Mars Hydro 1600 LED light, a big fucker. Ok, it was dropped into my lap, lol
It pulls 550W from the wall in veg mode and right now I have it over my rooters table, about 24" above the table. The short babies are fine, but the ones hitting 8" tall are beginning to look deficient; leaves getting a bit pale, very purple stems, leaves growing in a sort of droop. They're plenty turgid, just not sticking straight out. All other plants using the same batch of nutes from the same reservoir look great.
I've seen light bleaching before, there aren't any dead spots on these.
Best I can guess is mag or sulphur, but only when under the blurple gaze of the new light.
Thoughts?