Cool, might get a couple more airstones too if it's a good sized box. I use FF, Botanicare Pure Blend Pro and House and Garden. I like Botanicare best, most organic and then I like House and Garden.
Do a google on Botanicare, you want the whole series, Grow, Bloom, Cal Mag, Liquid Karma (kicks butt), Hydroguard, and Clearex...whew. And get some Sweet or General Hydroponics Sweet. As for flower enhancers I
ll let the others chime in but I use the FF 3 part (Fox Farms).
Yes pH and nute water, keep does real low, how old are the plants?