400w + 4' lightmover, hydroton + rockwool setup. Need help tweakin

i plan to scrap and restart everything this grow. I want to add something to lift the buckets off the tub so they drain better and so some dont sit higher than others. I've had severe stunted growth and really am hating the shit out of it. the plant u c on the end is just a hempy by the way. so yeah heres some pics and i was hoping i could get some tweakage from all the experts. I read up on things every day i just cant seem to get the hydro setup working right. i keep the ph around 5.6-5.8 and res from 65-68. The res is a 27 gallon (filled with ~15 gallons and has 8 flexible 2' airstones in it from that big pump. I know thats overkill i just wasn't using it so i added it in. So heres the pic's.. flood cycles are 2 minutes every 4 hours, lights on only. Also want to know what i can add as far as nutes and stuff (nute schedule) goes; i want a flush solution and wasn't sure what to get and just got that humbolt carbo supplement. thanks everyone please dont be afraid to say whatever im open to anything at this point. here they are...
also using Pro-tekt.

oh yeah and the pots have big holes in them and then are lined with burlap and filled up with hydroton. the plants are in rockwool starter cubes. Im pretty sure the problem was that they weren't sitting in the water correctly and only one was at a good height, which is why it is way bigger.

Damn still no posts ? C'mon fella's

I wish could help I know 0 bout Hydro except basics from reading bro

word man- ill post updates when things kick off then. any advice is helpful

Bump!!!!!!