Media that drains too well?

[Cstanm700]

I recently Bought 3 Phals from Lowe's. They were in the clearance sections so I bought these 3 2 quart orchids for 4.50 a pop. Upon further inspection the root systems were in great shape hardly any rot from overwatering. I re-potted into a media made of 85% of these large bead like clay things 10% medium coconut husks and 5% charcoal. The Mix drains water like a sieve but in a few hours its totally dry. Could lack of water retention harm the plants?