Hiya dontknowmuch,
sounds like you have a nute burn to me, post a pic, go ahead. And i'm feeding with organic teas, although i'm still in the tuning stage. Bat guano, fish emulsion a few other things, as natural as i could find. I water at different times as my plants are all different sizes, but i let them dry out before i water/feed again. You are most likely over-watering, of course i can't say for sure but that's the most common mistake we make when starting these wonderful projects.
ALso, i picked up a carbon filter today, and have no idea of the cfm (made in foreign land with no label) Its 16" tall and an 8" diameter. I included a pic so if someone has one similar , we might be able to come to a reasonable guess.