Afraid to repot phalaenopsis after a bad experience

[jimkamal]

So at the moment, I am trying to recover 2 of my phals that have lost most of its roots after I repotted them. I posted a thread in a forum about it and now hoping that I will be able to save at least one of them, since the other one doesn't look promising. Anyway, I have 2 more phals that I got from an orchid show that are planted in complete sphagnum moss. They are both in bloom, and have new leaf growth as well. I don't water them often, only to water when I stick my finger into the moss and feel that it's dry, probably every 7-10 days. I want to repot it in complete bark that is sold at lowes from better gro that looks good. I know that they sell the phal blend as well but I think I just want to try complete bark. Any good advice for me? I want to wait until all the blooms fall off first before I attempt to repot it in a clear 4 inch orchid pot. It is currently in a regular green 4 inch pot. I am so afraid to repot now since my last experience!!