marrying a plant to it's medium!

[CodiMN]

Hey all, sorry I've been a ghost for a while.

I tend to have most of my orchids in a bark mix and one in s/h from Ray's.
I've sadly not gotten my orchids to re-bloom (many are young I know ), so I've wondered if my medium could be at fault. Lots of root and green growth, just no blooms.
What types of medium do you like to use for your 'chids? Let me know what 'chid likes which medium best! I'm going to try switching lighting next...that'll be my next thread!