Have used both General Hydroponics three part, and Botanicare Pro Bloom and Grow, Bloom is soil formula. I grow hydro and the comparison is great. Pro Bloom is the shit for sure. GH has shown less bud and much more nute burn issues. Never get a burn with Botanicare Bloom For Soil in my hydro. Why soil formula, well because it has more k in it and it does the same thing basically. Anyone else care to comment on their experiances with these please chime in.....