Oh No! Mustard Algae?

[Kelleyaynn]

My pool water is nice and clear - just gorgeous. However, yesterday I realized what I though were stains on the side of the pool are probably algae - I could rub some of it off with my thumb. It's not green (and the green algae cleared right up when I initially shocked the pool), so I'm afraid it might be mustard algae. Though my pool gets a lot of sun, it is found on the side that is shaded most of the day, and in some "rough" areas of the concrete. Here are some pics:

My numbers are:

FC - 4
pH - 7.8
TA - 100
CH - 320
CYA - 45

Thanks,

Kelley

 

[linen]

That does sound/look like it could be MA. Have you read this pool school article?: http://www.troublefreepool.com/pool-school/mustard_algae

The first step is the normal shocking process.

 

[Kelleyaynn]

Thanks, that's what I figured I'd have to do. Just wanted some verification that it probably was mustard algae.

Then, when that's done, I think I'll add borates.

Kelley