Here are 3 pics of my seedlings. They were put in on 3/25. I can't figure out what is happening. I germinated them in paper towel, planted them in 50/50 soil/perlite. The soil has no fertilizers. I have watered with brita tap water that was at about 70*F. Temps in the cab may have reached 85-90*F for the first 5 hours of their 18/6 cycle for the first 3 or 4 days. After that temps have been right below 80*F with lights on ant about 71* with lights off. I have been using nothing but water until i started to really worry and then i watered once with 3 drops superthrive per 2 liters. They have been turning yellow with leaves twisting up and then leaves turn brown from the tips in. They started this before suprerthrive b.t.w. CFL lighting, 8x26w 50/50 cool blue/daylight. CFL's are 3 inches away and there is a fan inside cab and an exhaust fan for the cab.
