question about my nutes... first grow

So I've been following the feed schedule that came with Fox Farm Trio. I mix the recommended amount per gallon, however I don't know whether to feed 1 cup or the full gallon. Do any of you guys have suggestions on this?

Next, the trio is all I'm feeding. I'm week 4 into flowering. Is there any other nutrients I need to be giving my plants?

How many times a week are you feeding? FF has a whole line..more then the trio pack. Go to the FF website and see them all there. What do you mean 1 cup or whole gallon?