For the last month the filter continues to put algae back in the pool. Chemicals are correct according to our basic test kit. (Not the TFP kit). As per pool store instructions we vacuumed to waste every day. Then rinse the filter, back wash the filter, then rinse again. At the same time we were shocking the pool and keeping the chlorine levels correct. But every time we turn the filter back on (even after backwash) dark matter comes out of the jets and back into the pool. Finally got a "pool professional" to come out he said he never saw green stuff come out to the jets like that before (not helpful). My uneducated idea was there had to be a filter problem because there was not much suction when vacuuming, the multi-valve did not move easily and the spider casket seemed all but dissolved. So a week ago I replaced the whole mulit-valve apparatus. This seemed to make a difference as we could vacuum better. The pool got clearer and while still cloudy the pool looks better. Yet every morning there are piles of dead algae (or at least I think it is algae) at the bottom of the pool. Each day I vacuum to waste, rinse, backwash, and rinse again. Turn the filter back on and watch the dirty water flow back in the pool. Each day the dead algae is back on the bottom. The kit we have continues to tell us our chemicals are right. The water inside the filter is always green (maybe that is normal). The definition of crazy is doing the same thing and expecting different results. Can someone please tell me how my filter can once again provide clean water back in the pool? Is it a pump problem? Filter problem? Chemical problem? Air Leak problem? I have read a lot of the forums and haven't found an answer yet.