I use GH 3 Part formula, I also use the Flora Blend, Floralicious Plus and the Diamond Nectar. I use Rock wool as my medium and I am getting great results. A little stretch between nodes and the salt deposits I've noticed bit one thing I like about the rock wool is you can keep everything really clean. Unless I go soil or ebb and flow I will stay with this nute combo. Mix 1 gal at a time g/m/b/dn/fb/flp. Mix well between each different nute/ supplement and you should be fine. Be careful not to buy organic notes for hydro!!!