I live in a semi-arid environment and I water my phals potted in a bark, charcoal, perlite and coconut husk chunk mix every 2 days or so. They seem happy.
I read an orchid saying a while back and since heeding it, my orchids have done even better than they were doing. I don't remember where I read it or I would give attribution (I am not a plagiarist!) It goes something like this.
'Grow the roots and the orchid will follow!'
good roots= happy orchid