Hayward 60 sf DE filter, Hayward 7 position multi-port valve, 1HP motor, vinyl liner.
After opening this year and my first backwash, I clearly saw clouds of DE blowing in to the pool from the returns. I suspected my old multi-port valve probably had a bad gasket; I had replaced it a couple years ago and had a fit getting the old gasket out (almost like the factory had glued it in). After removing it, I did open it and sure enough the gasket was really messed up.
So I bought a new multi-port valve (yes a new valve, not just gasket), vacuumed like crazy, backwashed and it seemed fine. A month went by and I noticed the filter pressure really wasn't rising; So I took the filter apart and soaked the grids over night. Looking carefully at the grids, they all seemed fine to me.
Re-assembled and added DE, and every day now there is DE on the floor, mostly along the edges at the bottom.
Is it possible there was just still DE in the pipes from before? Maybe my grids have a rip somewhere I couldn't see?
Running the Polaris stirs it up well, but it returns the next day. Is there any concern to swimming in the water with that stuff mixed in? Is it possible I am putting too much DE in? I try to follow the recommendations and have been doing this for 6 years now.
I hate to just go and buy new grids without being sure.
Any advice or experience is much appreciated.