90 is too high man. Growth starts to stifle between 80-85 degrees depending on some other factors. 75 is perfect IMO, although it depends on strain, method of growing(hydro/organic), etc. Get those things out of the attic ASAP. Unless ventilation is primo, attics are terrible places to grow IMO. Too much heat, insulation may possibly be contaminating the environment as well. I agree that over-fertilization is probably the main culprit, however those temps. are not helping at all.