I've never used GH's products but it's probably a good idea to follow the directions on the container. But you're right in that alot of these companies do not give you exact instructions on how to use, how much and how often (which sucks). You might be able to get info on this from their website. Rusty has said that Foxfarm has feeding schedules on their site and maybe GH does too. If I were to guess, I'd say that around 700 ppm while they're small and raise it as they grow, perhaps to a max of around 1200. That's just a guess. In hydro a pH range might be 5.8 to 6.5, soil a little higher 5.8 to 7.0.
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