they are meant to be used together, actually, in conjunction with other products as well. Please check out their feeding schedule: http://www.foxfarmfertilizer.com/soilfeed.pdf

I'm sure theres ways to get around using this or that, but they've taken some of the guesswork out.

of course, its best to use less than recommended.

__________________
Come on and let the good times roll,
We're gonna stay here till we soothe our souls,
If it takes all night long.