Hi, Gordy,

Yeah, that's a real puzzle. I seem to remember Pooldoc saying that AG pump and filter systems were notoriusly inadequate....perhaps yours just needs some time to clear things up.

Breakpoint was certainly a good thing to do. I'm surprised you didn;t get more visual results...at least not yet.

Carl's ideas make a lot of sense. I have a personal affinity for sand filters so I try hard never to blame them for any inadequacies. Finer filtering just may work, tho.

One last thought, I would be hard pressed to test or take advice from most pool stores. This forum continually offers better advice and there are continual stories of pool stores testing poorly and selling vigourously.

What are you testing with now? I would tend to trust your own numbers rather than the pool store. If you can, keep posting on the forum and don't give up. I and many others will be interested when you discover the cause.