Having trouble repotting my bulbophyllums

[Bulbophilia]

Hi orchidboard, I've been having problems repotting my bulbophyllums. I had purchased a bulbophyllum longissimum and an elassonatum and repotted them soon after purchasing them but I haven't been able to find a good setup for them. I initially potted them in sphagnum moss with a drainage layer of packing peanuts and would spray the top of the sphagnum with peroxide once a month due to the fact I have no air circulation where the plants are. They grew mouldy so I repotted them again, this time I potted them in a 50/50 bark sphagnum mix and now they are drying out so fast I have to water them every other day. How can I pot them so I can water them twice a week and not grow mould on them?