Stumped. Mustard algae, pollen, or something else?

[yankeedynastybob]

Stumped. Mustard algae, pollen, or something else? Pollen in SC has been very bad this season. Mainly seeing this on tanning ledge and skimmer socks. Not present in deep end or on walls. Chlorine level does not seem to be infected by it and it vacuums up easily, kind of cloud like. Returns next day and vacuum again. Any suggestions or recommendations appreciated.


PoolMath Logs
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Dog Pool
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Build Type: Plaster
Volume: 20000 gallons
Chemistry: SWG
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Latest Test Result Summary:
FC: 2.0 (1 hour ago)
CC: 0.0 (1 hour ago)
pH: 7.8 (1 hour ago)
TA: 100 (1 hour ago)
CH: 300 (1 hour ago)
CYA: 30 (1 hour ago)
SALT: 3200 (1 hour ago)
TEMPERATURE: 81° (1 hour ago)
CSI: 0.14 (1 hour ago)
==========================================
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Test Results 05-14-2025 @ 04:41 PM
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Free Chlorine: 2.0
Combined Chlorine: 0.0
pH: 7.8
Total Alkalinity: 100
Calcium Hardness: 300
CYA: 30
Salt: 3200
Temperature: 81°F
CSI: 0.14

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Test Results 05-10-2025 @ 10:48 AM
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Free Chlorine: 4.0
Combined Chlorine: 0.0
pH: 7.8
Total Alkalinity: 100
Calcium Hardness: 350
CYA: 30
Salt: 3400
Temperature: 76°F
CSI: 0.15

 

[PoolStored]

Your FC is low. Likely algae.
Do this test tonight. Link-->Overnight Chlorine Loss Test
You fail you slam. Link-->SLAM Process

 

[yankeedynastybob]

Your FC is low. Likely algae.
Do this test tonight. Link-->Overnight Chlorine Loss Test
You fail you slam. Link-->SLAM Process

Will double check but Chlorine level had remained stable. Lots of rain recently and had to drop about 3 inches of water today.

 

[yankeedynastybob]

Will double check but Chlorine level had remained stable. Lots of rain recently and had to drop about 3 inches of water today.

Also this has been occurring for weeks

 

[PoolStored]

You have been flirting with algae for a couple weeks.
You really need to follow this and keep your FC in range for your CYA. Link-->FC/CYA Levels
Do the OCLT.