Lady slipper orchid

[Dreamscape]

Help me out guys,
I've got a lady slipper orchid, yellow with dark spots (if that matters) Im having trouble getting it to bloom it has sent out a new flower spike and new growth but no flower. Since the new growth Ive increased the day time, so it gets more light. Let me know of a good fertilizer if thats what I need.
Dreamscape

[tunachris]

This is a nice lady slipper that blooms for me once or twice each year. It has gotten quite large. I have not had a great deal of re-blooms with Paphs, not sure what I can do to ensure they bloom. I have tried varying the amount of light, keeping them outdoors till it gets quite cool in the fall, and I have used different types of fertilizer. I keep them in fairly small pots, as they are supposed to be somewhat rootbound. I have switched many to a mix of 3 parts coconut husk chunks, 1 part charcoal, and 1 part perlite and they seem to grow pretty good, but not many re-bloom. I have even tried cutting back on watering them, to no avial.