New house, filthy pool, FNS36...
Replaced the grids but because the pool was so dirty pressure went up to 30 almost immediately so I backwashed, and kept going.
Overnight, pool level dropped, pressure on FNS36 dropped to 0. So I filled the pool back up and turned the filter back on.
The filter's middle has separated, even with the band on tight. Water's leaking out... turned off the filter and posting here.
I'm going to go take the top off and survey the damage.