I have a Hayward 166 Sand filter and Zeobrite as the media. I've been dealing with a problem ever since the pool was installed 2 weeks ago. I had cloudy water after the Zeobrite was backwashed, and found small white material in the bottom of the pool.
After a close to a week with no improvement, I called the PB and he suggested that he maybe didn't get flushed out enough initially. So I backwashed, rinsed, and added SeaKlear clarifier per his recommendation. Over the next couple days, the water cleared, and was crystal clear.
Last night, I saw some grass clippings in the lower pump basket. I shut the pump off, turned the shut off valve on the skimmer side off, turned the filter to OFF to prevent a backflow of water since there is no return side shut off valve. I cleaned the basket, put the top back on , turned the filter to FILTER, turned the skimmer shutoff ON and started the filter. I checked for leaks, stood up and a cloudy white mess was blowing out my return line again.
So my question is... do sand filters all do this when they are shut off? Were my steps wrong?
I wouldn't think so, but just wanted to double check. Now I have to start all over again cleaning up the pool. What's really interesting to me is that the filter had been at 22lbs pressure for almost a week (since the last problem) and as soon as I put it back on filter and started the pump, it dropped to it's clean pressure of 18lbs.
Any advice you can offer would be helpful. Thanks