How do I care for my re-potted orchids?

[Claudia9421]

I have three orchids that I repotted about a month ago. Two of them are Phalaenopsis and the third an Oncidium twinkle. I used a pre-made orchid potting mix which generally consisted of tree bark and charcoal and I added some perlite to help with water retention. I've placed them in new pots with a small bowl underneath that contains little glass stones on which the pots rest. I keep them in my bedroom on a wall and they recieve indirect light the entire day. I try to water once a week as the bark dries out quite fast. My one Phal is not looking so good; the leaves are all droopy and seem to be dying. The other two look fine but I am worried they are following the same path as the first plant. Any tips would be great as I am trying to start a small collection and these that I have are very sentimental to me. Thank you!