As a bit of a progress update yesterday when I got home from work I removed the stairs and gave the pool another scrub down. Note to self: removing the weighted steps makes this process a lot easier. I did a FC test and saw that it was down to 13.5 PPMs so I added 5 cups of 12.5 oz bleach. This was down from 16 earlier that morning, and 16.5 the night prior.
This morning I didn't have time to do another test, but I did spend a few minutes giving the pool a good scrub down before leaving. Because of the chlorine loss during sunny hours yesterday I decided to turn on the chlorinator before leaving so I could maintain that FC 16+ PPM level when I didn't have time to babysit the pool. Now home this afternoon I see the FC level had spiked to 21 PPM. Yikes. Well, at least that's above 16. I turned off the chlorinator and gave the pool a more extended scrub down compared to the half-assed scrubbing in the morning. I'll probably hit it one or two more times before going to bed this evening.
Visually the pool still looks the same but I am optimistic.