The guys at the AG store where I go have recommended these nutes/supps: (GH)FloraNova Bloom, (GH)KoolBloom, Shooting Powder(0-9-20), Humboldts Gravity, also Blackjack Liquid Humic Acid I've been using the Bloom about every 10 days, and the Humic acid everytime I use nutes/supps, I've just been randomly using the Koolbloom and shooting powder....what I'm wondering is when to use the other stuff. I've heard to hold off on gravity untill last 3 weeks. Oh BTW...how much shooting powder per gal... my buddy uses 2.9g/gal I have: 400w HPS & 400 MH 3weeks into flower 8-10 weeks total flower time.