You'd have solid results using the FF weekly feeding schedule. (it's on the FF website) Using bottle directions, they assume you aren't using the other two in the trio, and it can screw-up your ladies if you are.

I personally feed twice a week, but at half-strength with each feeding. Same weekly totals as listed on the website, but it's easier on my ladies.

Soluables not recommended till you know what you're doing. (couple of dozen grows) They can easily overstress the ladies and have negative results if overused.