But realistically with all new sand, I'm not filtering down to 10 microns, I'm probably around 40. At 40, I can see some dirt getting through.A sand filter will absolutely catch dirt down to about 10 microns or better. So unless your sand filter is a flower bed, the filter is not the culprit. You are getting dirt in your pool and it needs to be vacuumed. Your skimmer is not going to catch it unless it is floating.
The problem is, I vacuum and it comes back after running the pump/filter. Every time. If I don't run the pump/filter the pool stays clean. How can a filter or pump suck dirt in, when it's on a polyformed stand off the ground.
I've vacuumed to waste 6 times now, and the dirt keeps coming. Pool vacs aren't great, but even if I was getting 40% of the dirt and the other 60% was getting stirred up, I should have a diminishing return of debris, and I don't.
I'm close to the point of closing the pool.
Unless there is a leak in an O-Ring somewhere on the valve or fingers assembly/tube that's preventing the water from being filters, and it's just recirculating so everytime I run the filter, anything floating or suspending isn't getting filtered, but just ground up and spit back out the return.
How can I check this?