My two month old sand filter keeps blowing fine dirt back into my pool. I've tried back washing and rinsing...I've tried adding cellulose...I've tried flushing the sand till the water runs clear and always it's the same thing. Within ten minutes of turning the pump on fine dirt starts collecting at the seams and wrinkles on the bottom of the pool...the longer I let the pump run the more fine dirt appears. I though maybe bad sand so I ran the pump on recirculate and the same thing happened. The pool water itself stays clean and clear and it does not turn cloudy at all. If I stop the filter action and vacuum this fine dirt to waste and then shut off the pump the bottom of my pool stays clean. I got desperate this weekend and took the filter completely apart...triple cleaned the sand...check the stand-pipe and all laterals...took the multi-port apart and checked the spider gasket. No damage to the stand-pipe or laterals and the spider gasket looked like brand new...no knicks, grooves or twisting. When I say triple cleaned the sand I mean that I first took the multi-port top off and flushed out the sand until the water ran clear...then I dumped all the sand into a screen lined milk crate and flushed it again...then after reassembling the filter I ran it on backwash for 5-mins and then rinse for 5-mins. It didn't help at all...10-mins after turning the filter back on the fine dirt was back. I'm about ready to tear the pool down...we're in a drought out here and it's wasteful to have to vacuum to waste everyday. I've taken to doing three day cycles...I'll get the chlorine level up to a five and run the pump for 12-hrs then I'll vacuum all of the fine dirt to waste which brings the level down two to three inches which I replace with fresh water then I shut the pump down and we swim for a couple of days without filtration or water circulation. I keep the chlorine between 3 and 5 during our swim cycle...adding when needed and then getting in the pool and mixing it with arm and leg movement. I'm desperate...I like my pool...does anybody have any idea what could be causing this?