I started germinating pepper seeds and they have started growing. I feed them with a miracle grow fertilizer that had lots of nitrogen. I also read that when the plant starts to flower, I should be feeding it with more phosphate and potassium. So I found two that I am interested in. A miracle grow instant feed bloom booster and a vigoro slow release bold blooms. They are both 15-30-15. I am leaning towards the vigoro because of it's slow release design. But is there a preference?