I had a pretty serious water issue when I opened this spring (first season as a pool owner)... While cleaning up the pool my filter would gain pressure and I would backwash as is normal. Since I resolved the water issue, my pressure has not increased at all. My pool is clear and all is well. I have backwashed once or twice even though the pressure had not increased just to make sure it was clean. From what I understand there is no harm in backwashing "too much". In other words, you cannot backwash too much. Also I plan to add a small amount of de to my sand filter (search other threads on the forum if you are curious about it) in order to 1) make sure my sand isn't channeling, and 2) enhance the filtration. I have also read about washing the sand with a hose, but I am not planning to tackle that until the end of the season. None of this really answers your question, but it does give you some other areas to explore.