If your room temps are 85-90 then the water must be pretty warm too and I think that may be your problem. Plants do not grow very well in temps over 80 degrees (slows down photosynthesis greatly) and if the water is too warm for your roots they won't do well either.

I thought about telling you to increase nutes but I personally would not.....I don't think that's your problem at all. When in doubt....always use less nutes which may not be great but won't kill them as opposed to too many nutes which can kill them pretty quick. They just don't look like a nute def.....I swear it looks like a ph lockout so maybe help needed has a good point going there about water temps and ph.

10 inches is usually ok for your light but just because you have sick plants you might pull it back from them a foot just to reduce stress and because your room is pretty hot itself.