I have used Jacks 20-20-20 for a FULL grow from seed/clone to harvest a few times. Some times it needs a bit of cal.mag so I use an Epsom tea. I'm testing Jacks Bloom Booster. Mainly from the advice and research of Uncle Ben and RiddleMe. Here's a few main things I learned.
1. Organic and Chem. fertilizers are equal, no organic is somehow better.
2. General botany and horticulture practiced from landscaping apply to Cannabis equally.
3. Soil can be amended and tested for cheaper than expensive soil. (thx UB)
4. Ceramic Metal Halide are a great HID for horticulture. (thx RM3)
5. Follow university peer reviewed scientific evidence.
So instead of bashing on UB, read the links he provides. As he says 'trade secret' ingredients are a clue to coming BS.
Daniels