that sounds like a good find actually, but its only suitable for mid-late flowering.

during veg, you want to find somthing with more N, and less P & k
like a 10-5-5 or whatever, they are easey to find, just look for a "grow" fert or a gerneral tomato type feed to start off with in mid-veg....then once flowering is underway, you can start introducing the fert you found in the garage.