this is a 2 year old thread. good stuff tho, the pro and calcium nitrate are basically marketed to professional greenhouse growers who don't want to mix their own salts from scratch for whatever reason, but are not stupid enough to buy home hydro industry bottled nutes.
There's several other fert companies and farm supply stores that make virtually identical products. I am always surprised that mmj forums don't recommend these sorts of products to new growers, as they are obviously much higher quality (also much cheaper) than what ppl get at hydro stores. Their must be lots of product reps on the forums lol.