Hi @jay , I agree with the others here, we need more info on your set up. Temps, air circulation or lack off, over watering etc. If you can come back with the info I’m sure we can all help you.
As for light intensity, I run 30 watts of screw in LED over 3/4 of a square foot with out problems. Managing heat is the problem in a small setup. And as you know we have had a very hot summer here in Qld this year.
We’ll sort it out, we just need more input from you.
Cheers Johnny