Does anybody know what this is? I'm new to pools. For three weeks I'd find algae blooms in the pool. After 3 shock treatments I went to a different pool store. They gave me copper strike, a few hours later the water stopped circulating. When we took the filter apart this is what we found. FYI, I am switching to the TFPC method next season.
Sent from my SAMSUNG-SM-G870A using Tapatalk