We replastered out pool in September. We checked out other pools (older and recent) that the company had plastered. We chose to go with white plaster and were happy with the other pools they showed us. Since the replaster (which looked great at first) the plaster has begun to mottle and get streaks which seem to be increasing. The company said this was normal and nothing they could do. Can anyone explain why this happened and if indeed we have to live with it?