I had a nice purple and white flowering, hanging plant that my purple flowers are fading fast.?

Question:I added some rich soil and miracle growth. Should that do it or should I replant? I got the plant from the grocerie store and the soil feels real spongy or light. I usually water it every other to every day since it has been hot in Missouri.

Answers:
deadhead=pinch back old blooms. if that doesn't do it then repot