Possible mustard algae will not go away

Melissadittmer

New member
Jul 30, 2020
3
Denton NE
Pool Size
21000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
We are shocking using the slam method for mustard algae and we are not making progress after about 32 hours. Chlorine just dropped in the few hours we were at a baseball game after holding for most the day. I’m even using a bit higher amount of chlorine to try to beat it. Our alkalinity will not lower below 150. I continue to add muriatic acid but it stays consistent. Running jets to maintain PH. Water is very cloudy and light to sometimes dark yellow over white steps. We are brushing the sides and vacuuming once or twice a Day. Water appeared to start to look bluish this morning when at 40 FC but it’s back to yellow/green tonight.

FC was 26 just added enough for 40 to get us thru night
CYA 50
Alk 150
Calcium 300
Ph was 7.4, now 7.0 so turned jets on again

Thanks for the help
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,014
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Welcome to the forum!
I believe you mis-read the Mustard Algae protocol. You are to complete a normal SLAM Process, using SLAM level FC, then when you pass that, take your FC to Mustard Algae level (60% of CYA) for 24 hours. Then maintain an elevated FC (~20% of CYA) for many days to eliminate the Mustard Algae.
You cannot accurately test pH when FC is above 10 ppm. Only test you need to do is FC.
I suggest you read ABC's of Pool Water Chemistry.
 

Melissadittmer

New member
Jul 30, 2020
3
Denton NE
Pool Size
21000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
Hello. I tried the normal slam and it was not clearing up. Then I noticed floating yellow wet dust-like stuff in the water so thought it was mustard algae, so I thought I needed to go this route. I’ve read the abc’s Several times. What are you recommending I do? Thanks!
 

Melissadittmer

New member
Jul 30, 2020
3
Denton NE
Pool Size
21000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
Welcome to the forum!
I believe you mis-read the Mustard Algae protocol. You are to complete a normal SLAM Process, using SLAM level FC, then when you pass that, take your FC to Mustard Algae level (60% of CYA) for 24 hours. Then maintain an elevated FC (~20% of CYA) for many days to eliminate the Mustard Algae.
You cannot accurately test pH when FC is above 10 ppm. Only test you need to do is FC.
I suggest you read ABC's of Pool Water Chemistry.
I should mention I was doing the normal
Slam for around a week prior.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
44,014
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Yellow algae occurs in a shady portion of the pool, normally a wall, and will come off the wall when brushed and disperse easily. What you described sounds like pollen.

Have you read Mustard Algae - Trouble Free Pool
 
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