Pamsel, I really identified with you; I had no idea what yellow algae looked like either. I assumed it would be clumps of yellow slime hanging on the side of the pool....wrong. Mine looked like brown dirt/dust had blown into the pool and clouds of it could be stirred up everytime I used the brush on it. My pool never got quite as dramatic as yours though.

I sent my ancient Kreepy pool boy to clean it up daily and he did---but it was always back the next day. I wasted a lot of time trying to clean that stuff up before I realized I had to KILL IT!!first.

I used liquid laundry bleach too. I wonder if using that will stain a pool or if the yellow algae leaves stains behind?

Now I am a vigilante; I give every suspicious speck a threatening look...