My neighbor is out of town on vacation and he's asked me to go over and toss a little bleach in the pool for him. Since he left yesterday, this morning was my first visit to his pool. There is a pretty solid band of algae from about 8" deep to about 24" deep. Seeing a large bucket of pucks poolside and three floaters in the water, I feared the worst regarding stabilizer. I grabbed a sample of water and brought it home to test. The results are puzzling to me.
CYA: 40 (!)
I did not test TA or CH.
To me, the numbers look ideal for algae prevention, yet he's got quite a bloom going there. The only thing that seems off to me is that the pool equipment wasn't running when I went over. I don't know when he runs it or for how long, but inadequate circulation is the only thing I can think might be allowing that algae.