Well since you're already doing that part, here's plan b.
Get yourself two boxes of seabird guano.
One box of 12-8-2 for veg, and one box of 1-10-0 for flower.
Use the 12-8-2 at 1/2 tablespoon per gallon of water, and water as usual.
Use the 1-10-0, at 1/2 cup per plant, stirred into the top of your soil one week before you put them into flower, and again after two weeks of flower.

Or you can use bat guano if it's affordable. Just be sure to use the high N in veg, and the low N in flower.