I'm reporting back as Richard's grateful student. He came over to my house this afternoon and spent 3 hours educating me, a pool dummy!
He patiently mapped out my circulation system, which is a total maze with three pumps and LOTS of mysterious valves. He showed me his fancy speedstir test kit and generated the following results:
The pool water is clear. Plaster shows a bit scaling.
My pool recently had an algae breakout and just went through Leslie's Yellow Out process. During the process I put in their Yellow Out algaecide, and shocked the pool with 9 lbs of Leslie's Power Powder Plus, and finished with 10 capfuls of Pool First Aid. But yellow algae is still visible. Richard even spotted some green stuff in the skimmer opening.
Richard suggested water replacement or reverse osmosis to reduce the CYA. Till that's done, I need to keep putting in chlorine to prevent the water from getting worse.
Thank you, Richard, for such great schooling! Oh, and thank you for saying I was not fat even though I was too buoyant to touch the . pool floor.