I finally got a sand filter to replace the cheap one that came with the cheap pool.
So I got the biggest cheap filter I could.
Here's the issues:
1: there is sand in the pool. How much is too much? If I were to estimate it would be a tablespoon or less. It does come back a bit after a vacuum, but seems to be decreasing.
2: if I let the pump run for more than a couple hours the sight glass is getting many air bubbles and I need to stop and bleed. Also whenever the pump is turned off lots of air goes into the sight glass and pool. I'm pretty sure I don't have any leaks.