Coots mix under LED, yellowing tips.

Hey guys,

I just cant figure this one out. I've got symptoms on all plants under cob led in raised beds. The plants are growing, but the tips and margins are burnt only on the new growth. The last run in this room went fine and the soil hasn't been amended. Soil is kept nice and moist and grow environment is between 77 and 81 degrees Fahrenheit and around 55 percent RH.

The only things that have changed since the last run are: 1.) I ran a sulfur burner one night a few weeks before replanting the room due to some PM issues with the last run. 2.) I installed a mini split and have not been running an exhaust fan. The interveinal chlorosis on the older leaves is something I have dealt with since working in this spot under LED, I am more concerned with the new growth. What do you guys think?

How far away are you keeping your LED's? Looks much like light burning on the tips and edges of your leaves, especially that it's happening on the highest setting leaves.

Logan Burke said:

How far away are you keeping your LED's? Looks much like light burning on the tips and edges of your leaves, especially that it's happening on the highest setting leaves.

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Lights are 4 feet up, dimmed to 20 percent. I've stressed plants with these lights, but not at that distance and intensity.

Ever figure this one out? I’m having tons of issues with coot’s mix under my LED fixtures. Tips yellow very easily and then if it’s not corrected, stress galore. I can barely turn my lights up on some strains.