Just to let you know, cut out that superthrive well before flowering. Superthrive extends the life of flowers. You don't really want your flowers to wait forever to finish. It's a plus for ornamental flower growers but we don't grow for decoration. Only use that stuff at transplant or some other time your ladies may experience stress but defiantly not every watering. A capful? It is recommend at a drop per gallon. I use it maybe 2 or 3 times during the life of a plant. In an experiment I killed a plant with superthrive. Sometimes less is more. Don't believe all the hype on labels.
Happy Growing
Polo