How did you solve the problem?
Same happened to me. New plaster, pool filled in Saturday. Pool man came on Sunday, added startup and . On Friday came and added conditioner and pool turned clear green after being perfect for over 4 days. We back washed our sand filter as pool man thought that it is clogged by the plaster powder, but that did not help. Anyway I new it is not true as pressure was at clean filter pressure. On Saturdy He added two small bags of shock, chlorin, and said it should be clear in 4 hours. Next day, which is today it is still looking green despit that all is balanced.
Moderator note: This post was moved from this old thread here: New pool startup GREEN!!