This morning's CL test showed I only lost .5ppm FC (CC is still 0) overnight with the filter running. So I'm guessing that whatever was consuming CL overnight was knocked out by that last shock.

The good news is I can stop shocking and don't have to tear down the filter. The bad news is we don't know if the overnight loss was caused by gunk in the filter, in the pool, or both.

So once FC levels drop to normal, 5-6ppm, I can work on getting the SWCG set properly and get to a normal maintenance routine (which usually doesn't involve much with our pool). FC was 12.5ppm this morning so I expect by this evening it will be close to the normal maintenance level.