At this point, a picture might help. It is possible that the medium is drying out too quick for the plant (especially that you have it in a clay pot), and the plant is loosing more water than it is taking in. Don't let the medium drying out with phals. I grow phals much wetter than other orchids, much much more than dends or catts. (However, phal species like it drier and many do well with mounting.)