So I thought I had a quarter-sized spot of black algae and then thought maybe it was mustard algae instead since this "mustard" colored bloom seems to sprout from the black algae, but after talking to the folks at Leslie's Pools and they didn't seem to have any idea what it was, I'm completely clueless and in need of help! FYI, I normally keep my pool in good clean shape (never had algae before), but traveled a bunch this summer so I don't think I was on the ball lately.
Noticed it a few weeks ago and looked around online and started scrubbing it with chlorine tablets, added a sock of tablets to hang right around the area, and scrubbed really hard (and for long periods, like 15-20 mins) with a wire brush and did beat it down somewhat, but it keeps coming back and always has at least some "mustard" bloom rising from it.
Finally trying to beat it with super doses of chems, where I shocked the pool (using Leslie's Chlor Brite chlorine glandulars) a few days ago and they applied Leslie's Silver Algaecide (where I applied one dose 1 hr after shocking and then after 24 hrs and still seeing this "mustard" bloom I applied another dose after scrubbing the area very hard again with a tablet and wire brush). So below is a pic of how it looked 24 hrs after the first algaecide treatment, so does anyone have any idea what this is exactly? I'm going to take a water sample with this "mustard" stuff back to Leslie's later today, but thought someone out there might be able to give me a heads up. Note that the area is only 3-4 inches down from the tile line, so I'm almost at the point of lowering the water, chiseling the area out (it's not that big), and then replastering that spot (at least I think that can be easily done by a DIY, right?).
Thanks in advance for any help ...