Do I have mustard Algae

Timmygreen

Active member
Apr 22, 2017
31
Yardley, PA
View attachment 59887View attachment 59888Hi,
I am a new pool owner, had a few months with it last Fall before closing it up for the winter. The algae that you see in the pictures, is the same growth I battled last fall. Chlorine, brush and vacumm would clear it up for about 4-5 days. I never brought the FC levels up higher than normal levels last year. I think it is mustard Algae? I plan on doing a SLAM to open the pool now. The pictures you see are after a quick brush, the yellowish stuff still on the steps and now more in the middle of the pool was everywhere before I brushed. If this is indeed mustard algae, and I bring the SLAM FC level to 19 based on my readings....how long is it safe to keep at those inflated levels? Thanks in advance...Tim
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Tim, even if it is Mustard Algae (MA), which I don't really think it is based on positioning, the treatment is initially the same - a regular SLAM (link below). Treat it as a regular algae/SLAM and maintain only the recommended SLAM/Shock FC level based on your current CYA as noted on the Chlorine/CYA Chart. After passing all 3 SLAM criteria, if you are still concerned about any possible residual MA, you can then increase FC to the MA level as noted on the Poolmath calculator - but only for 24 hrs after passing the regular SLAM.

Remember during the SLAM to perform all of the other tasks noted on that page to ensure success.

Also keep in mind some of what you see may simply be organic staining from previous algae. That should resolve itself with the elevated FC levels and consistent brushing to the effected areas.
 

duraleigh

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In The Industry
Apr 1, 2007
31,520
Sebring, Florida
Agreeing with Texas Splash, I do not believe that is mustard algae. You will need to brush during the SLAM.......more so than others.....to remove the organic stains.
 

Timmygreen

Active member
Apr 22, 2017
31
Yardley, PA
Thanks. Just fyi...that was yellowish stuff was covering everything, all the way up the walls and stairs until I brushed it the other day. I did do some vitamin c testing on other stains that were there all year round last year, even when I had the water sparkling, and those appear to be organic stains and not metal. This brings me hope that I can get the level of FC up this year, and remove most of them over time.

- - - Updated - - -

you can actually see my brush marks in the 2nd pic.
 

Timmygreen

Active member
Apr 22, 2017
31
Yardley, PA
Baed on the picture #2, would you start by vacuuming straight to waste, or would you just get the filter up and running and add DE before first vacuum?
 

Texas Splash

Mod Squad
TFP Expert
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While there doesn't seem to be an extraordinarily large amount of debris in that pic, you certainly can do a quick vacuum to waste first if you would like to remove the larger debris. Once that's done though, make sure your grids are charged with DE and start your SLAM. Good luck!
 

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