In need of advice from fellow hydro growers

I am about to pull out my teeth if I can not figure this out. I have a drain and fill setup, 150watt hps, 5.8-5.9ph level, using distilled water with advanced nutri, feeding 3X while lights on. She is also in flowering for 5 wks so I do not know what I can spray. She looked beautiful until about a week ago. The tips started turning brown on the upper fan leaves. Then the lower leaves started to get brown tips and curl under as well. I did adjust the feeding because I thought I was over fertilizing. Now brown spots are appearing on some of the leaves. I also just noticed that the roots that are towards the outside of the res have white fungus. I do not know what to do for this either. Its not a lot but I know that it can spread quickly so I need advice. I attached a few pictures. Please help, I usually get good advice from forums here and I hope this time is the same I do not know what else to do.

High water temps are the devil. If you are having root problems and you are running hydro, then most often the water is probably too warm, as well as maybe not enough oxygen being pumped into your res which will result in stagnate water and that will mess those roots up quick and the rest of the plant will follow.