Welcome to Orchid Board. Your answer is on this page (27) and many other pages! Just look further up and there are many people advising that Phals can take being re-potted even in flower and if you wait till it's done flowering, it may be too late. They don't like being stuck in tight soaking wet moss and will develop root rot very quickly. I suggest you read or at least skim some of this thread and you will learn from what has been said to many others.