i grow with the same wattage i keep my light 12 inches above. my plants grow really well with it. u should do the same just make sure it doesnt go pass 80 degrees in your room. but your fine with that.
I think it has to be a heat problem. The same thing happened to me and i also thought it was my small pots. i transplanted them into 3 gallons and theres was still no sign of growth. Then i checked the temp and it was around 85 degrees i dropped the temp to 75 degrees and it started growing...
I have a seedling, hes 2 weeks old hes fighting for his life cause hes not gdead yet. Well the problem is the cotycelon has turned yellow; one of the leave looks burnt at then end. it has 4 true marijuana leaves and now they are all curled down. they still have a nice green but the very tips...