That's exactly what I do, except I use SensiZym from AN. I've found it works at least as well, if not better. Plus I prefer to buy my nutrients and stuff in larger quantities, and SensiZym has a much longer shelf-life.

Gotta remember, this stuff has got enzymes in it (thus the "zym" part of the name) and it's basically organic materials. If it sits around too long it basically dies.

So yeah, bit of an Advanced Nutrients fanboi here, but I I'd recommend SensiZym over Hygrozyme unless you just can't get your hands on AN stuff where you live. Worth every penny IMO.