Sorry about the dual-thread confusion

With my cartridge filter, I cannot vacuum to waste; so if I vacuum, it'll be to filter.

Two schools of thought: (1) Let my Polaris buzz around, stirring up sediment and suspending it in the water for my filter to catch; or, (2) letting it all settle and trying to vacuum the bottom (which I cannot see).

Since I don't have Ben's test kit (sacrilege, I know...), and my hth OTO kit only goes to 5, it is difficult (to say the least) to test for levels of 30+. It takes a 5:1 dilution. But, my tests have ben consistently showing 20+. So, keeping my cl up does not seem to be the issue.

I am considering a partial drain/refill. I am not sure if a partial drain would hurt my plaster?