Hi Dave,

Yes, water is exiting the pool, but within minutes some of the stuff is back on the bottom of the pool. We can vacuum to waste and see some stuff reappear immediately. Then, if we shut the filter down and restart it a few hours later, it looks like it all reappears around the outer edge of the pool (in the line of circulation). The backwash thing has me stumped too. In the past the water would come out with a lot of force during backwashing and there would always be some dirty water come out weekly. Not this year - we have about half of the pressure when backwashing and absolutely no dirty water coming out. A couple of years ago we had a huge algae bloom after a heavy rain and the water was totally green. We shocked and cleared it up and vacuumed the dead algae to waste one time. One time was all it took. My water has been clear all year. This stuff was on the bottom when we took the cover off in May and we still can't get it out. There is absolutely no slimy feeling anywhere in the pool and the water is clear. That is why I think it has to be the filtration system.

Thanks!