Ivey

First-time pool, only 10 ft. diameter above ground. Found this floating on surface tonight after shutting off filter pump. Chemical balance of water is good, have been shocking regularly (about 1x week), running 1000 gpm cartridge filter pump regularly, and cleaning/changing filter, brushing every 2-3 days and skimming daily. No vacuuming (though I ordered an inexpensive manual vacuum last week that just arrived this past Friday). Have had some heavy rainfall over the last week. Did some searching online, and closest guess is white water mold. Can anyone confirm from this picture?