I have a 5,000 gallon vinyl liner inground unheated pool with a copper diode ionization system (Carefree Clearwater) and a Hayward 166T sand filter. This system was installed in 2011 in a weekend house in WV. The pump is a Pentair Super Flo variable speed pump, which is a new pump I installed at the beginning of 2020. All was going well with the system until late August of this year. Maintenance typically involves balancing the water chemistry with muriatic acid, TA Up, and calcium chloride, and then adding shock once every few months if algae starts to get a little out of control. The ionization system does the rest of the job pretty well. This summer, I went away for a month, and when I came back, nothing I did cleared up the algae. I hypothesized that friends who stayed there while I was away may have messed up the filter. So I changed the 3 year old sand to new pool filter balls and swapped in a brand new multiport valve and lateral assembly. I fine-tuned the water chemistry and double shocked the pool. As usual, the green algae died and turns to brown, but the filter is not doing its job. The pool has a fountain which will has in the past shown reduced flow as the filter gets more dirty - but this doesn't seem to be happening now. Further the filter pressure gauge shows 2 PSI and does not increase as the pool algae gets worse. This is a big mystery to me considering that the filter itself isn't that complicated of a device - and I've replaced most of the key parts! Any ideas for troubleshooting this are much appreciated.
FYI - the pool chemistry is within reasonable limits: VW_pool_chemistry
Cheers,
Jeff
FYI - the pool chemistry is within reasonable limits: VW_pool_chemistry
Cheers,
Jeff