Do you have them in the seemingly normal orchid see through pot that has very good drainage slots ? I now have 8 phillys, different colours etc, and they are going 'bananas' at present, I water once week by standing in water that I have added couple of drops of fertiliser to for 15 minutes then let them drain for couple of hours before putting them back on my East or West facing window sills. Before the stalk of my last one had time to die back it has thrown up 3 side shoots from original flowering stem , likewise on another and the flowers on the last stems are huge! Wish they were perfumed! I bought orchid mixture from my local nursery, cost about £3, but it is your choice and the choiced on-line are innumerable, so I went local!