Has this system had a successful harvest for you or anyone else ? If not I would be looking at other types of systems. You could change to DWC or bubblers real easy and cheap. It is most likely nute burn and what ever was in the spayer bottle. You could get the heat down a bit but do you know what the water temps are if the room is 80 ?

Hope the plants make it. It's alright if you burn the leaves off as long as the branches come on out good. Just alot of stress.

If you can get some better pic's and maybe fill out the form in the plant problems section. I guess this is an NFT system ?