I had to backwash my filter 5 times in less than 24 hours the day we opened our pool. I live in the country in Michigan.......no big trees but surrounded by fields. We opened it on Friday afternoon and the pressure kept climbing sooo fast, so I backwashed it every time it got too high. It was quite green as we had a very warm April but now a very cold May. It even frosted last night. It is still quite cloudy, but I will work on that this week. I haven't even tried to balance the chemicals yet......just wanted to get the dirt off the bottom and kill some algae so I could actually see to the bottom of the pool.