Is this mustard algae?

[pebblewrestler]

I keep getting this yellowish green algae that tends to stick to the sides of the pool. It will go away with a shock but comes back quickly at normal chlorine levels. It can be somewhat stubborn to brush off, but I'm not sure if that just some staining. I've read that mustard algae tends to show up on shady sides of the pool, but this appears where the sun hits as well.

FC 25 (just shocked)
pH 7.2
TA 112
Phos 700
CYA 50
TDS 2900

 

[Texas Splash]

I'm not so sure that's actually MA. Regardless, I do believe your first action should be to start a SLAM Process. But to do that you need a TF-100 or Taylor K-2006C test kit. Your test results look like they are from a pool store, so step #1 needs to be having your own kit to accurately perform the SLAM Process. Then if you feel the need you can do the 24-hr Mustard Algae treatment at the higher FC level.

Also see:
FC/CYA Levels

Mustard Algae

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