Mustard Algae?? Can't get pool clarity back

Perkn7997

New member
May 16, 2022
3
Ohio
Pool Size
24500
Surface
Vinyl
Chlorine
Liquid Chlorine
In mid June we had a bad storm that came through and as a result we had all kinds of debris in our pool. Cleaned it, didn't think much of it and several days later pool turned cloudy. FC was registering on the lower side of the target, but it never got to a point where the pool had no FC. I started to slam the pool, couple days/week later the pool started to clear up and there was lots of brownish piles on bottom and even the sides had this brownish stuff laying on them. I continued to slam the pool for another week while brushing the sides and the bottom several times daily. The material would poof into a cloud when brushed. I completed an OCLT and it was less than 1 with no CC. Pool continued to get clearer and clearer but the brownish piles continued to show up no matter how many times I vacuumed them with my robot or manually. About 3-4 days later the pool started turning cloudy again and at that time I became concerned I had mustard algae based on what I've read on here. I took the FC levels to the appropriate MA slam level that next day for a full 24 hours and have continued to maintain slam levels for the last week since. I have vacuumed the brownish material to waste 3-4 times, but every day there is still more regardless of running the robot or brushing the pool. The clarity of the pool is no where near what I am accustomed to so I am at a loss. I have dumped a significant amount of chorine into the pool and just don't seem to be getting back to where I usually am at. The water continues to have a greenish tint to it and not blue/sparkly like normal. I have done several more OCLT this last week and am always less than 1 and continue to have CC of .5 or less. Any advice would be greatly appreciated.

As of last night:
FC 10.5
PH 7.4
TA 90
CH 375
CYA 30
CSI -0.06
TEMP 83
 
You are raising your pool to SLAM level, which is 12 according to your CYA, several times a day?

There are three parts to ending SLAM. 1 - no visible algae, 2 - loss of 1 FC or less overnight, and 3 - 0.5 or less Cc.

Whenever you hit SLAM level, you are killing algae until you no longer have any algae. So just because your water looked clear, the fact that you were still killing algae meant you weren’t done yet.
 
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You should complete slam first (normal slam level)
Then after meeting all 3 end of slam criteria:
✅ CC is 0.5 or lower;
✅ You pass an Overnight Chlorine Loss Test
AND
✅ The water is clear.
(Crystal Clear w/no recurring algae dead or alive)
You would then move on to the MA protocols.
After which you may wish to maintain MA minimum for a while as listed in the chart linked in the article.
 
You got it 👍🏻
While doing the oclt occasionally is a helpful indicator of where you are in the process - wait till you’re crystal clear with no recurring stuff to do the defining oclt.
No need to wake up before the rooster till then.
Be sure to do all the things…
*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

You can also add a little de to the filter after backwashing to help catch the finer particles. Just be sure you’ll be around to watch the psi.
 
I’ve continued to SLAM for last several days, deep end still has a greenish tint to it and it’s not back to the sparkling blue we’re accustomed to. I’m seeing very little dead algae in the sweeper, running 2 times per day. Anything additional I should consider? Is it best to leave solar cover on or off?
 
I’ve continued to SLAM for last several days, deep end still has a greenish tint to it and it’s not back to the sparkling blue we’re accustomed to. I’m seeing very little dead algae in the sweeper, running 2 times per day. Anything additional I should consider? Is it best to leave solar cover on or off?
Leave the cover off for slam - also scrub the cover.
 
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