Phalaenopsis Fertilizer Help Needed

[meganreaux]

I have a collection of phalaenopsis that are actually doing quite well (I'm very proud of myself)-- all of them are in spike/bloom. But I'm having some issues: the 'chids aren't making as many flowers as they had when I bought them and the spikes aren't as tall. I'm thinking the problem might be fertilizer. Right now, I'm fertilizing weakly weekly with Miracle-gro 30-10-10. And once a month I use a Better-Gro bloom booster 11-35-15 with a little Super Thrive. I keep them in an east window, so they just get direct light in the mornings. What am I doing wrong?