Mustard algae that wont go away.

photo2u

Well-known member
Jan 3, 2010
100
Claremont california
Hello,

I am having some stubborn mustard algae that just won’t go away. I need help to kill it.
These are the details:
Pool is 30k Gallons. Below ground plaster kidney shape with a small round spa. The pump has been circulating for 48 hours none stop. The CYA is at 60, the PH is 7.0, FC 25 or more (test taken by strip at pool supply store). I do not have an accurate FC number due to the limitations of my Taylor k2005c testing kit.
1. First day I used 3 gallons of 12% Chlorine and 9 oz. of swimtrine plus algaecide (copper 9.3%)
2. Chlorine and the algaecide removed about 50% of the algae.
Since the chlorine & algaecide did not work well my local pool guy advised me to use 5 lbs. of algae destroyer concentrated stabilized chlorinating granules -99 %TRICHLORO-S-TRIAZINETRIONE. After two days of brushing 3 times a day the 10% of the yellow algae still there.
I have read most of the information regarding the algae at this site.
I welcome any input regarding my options to get the mustard algae out.

Thanks,
George from Claremont California.
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
10,964
Houston, Texas
You will need an FAS-DPD test to suppliment your K2005. This test will accurately measure high levels of chlorine, which is exactly what you need to take care of this problem. The FAS-DPD test is available from tf test kits. You will need to follow the shock process using the higher FC for yellow algae according to the pool calculator.This requires an FC level of 34 for your pool based on the test results you have posted.

It is important that you use liquid chlorine for the shock process. Liquid chlorine will not add any CYA or Calcium to your pool. You can clear the pool with just chlorine. Please do not add any more algaecides to your pool. Algaecides will increase the chlorine demand on your pool and will slow down the shock process. Algaecides are more effective as a preventative than they are as a cure.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,502
Sebring, Florida
Hey, George,

Good Morning!! :lol:

Mustard algae that wont go away.
Of course it will. Read zea3's advice carefully. You simply haven't held the Free Chlorine HIGH ENOUGH AND LONG ENOUGH to kill the algae.....it is a process.

Follow the link zea3 suggests and follow the guideleines found there and you will clear the pool.
 

teapot

In The Industry
Jul 25, 2009
574
London and France
George you haven't said what your pool is made of, concrete/plater/tile or vinyl liner. You absolutely should not use copper based products in a concrete/plaster/tiled pool just as Frustratedpoolmom says.
 

photo2u

Well-known member
Jan 3, 2010
100
Claremont california
zea3 said:
You will need an FAS-DPD test to suppliment your K2005. This test will accurately measure high levels of chlorine, which is exactly what you need to take care of this problem. The FAS-DPD test is available from tf test kits. You will need to follow the shock process using the higher FC for yellow algae according to the pool calculator.This requires an FC level of 34 for your pool based on the test results you have posted.

It is important that you use liquid chlorine for the shock process. Liquid chlorine will not add any CYA or Calcium to your pool. You can clear the pool with just chlorine. Please do not add any more algaecides to your pool. Algaecides will increase the chlorine demand on your pool and will slow down the shock process. Algaecides are more effective as a preventative than they are as a cure.
Hello friends,
Thanks so much for all the information regarding my little problem with the mustard algae in my pool.
Yesterday, I took my water to a local pool supply to get it checked. According to them the CYA WAS 100? That was very high? Maybe they did not take in to account the high level of chlorine in the water when they performed the test? The person doing the test did not use any strips. The CYA number did not appear to be correct to me.
Chemicals used AFTER AN ACCURATE READING OF 55-60:
1. 3 gallons of 12% Chlorine and 9 oz. of swimtrine plus algaecide (copper 9.3%)
2. 5 lbs. of algae destroyer concentrated stabilized chlorinating granules -99 %TRICHLORO-S-TRIAZINETRIONE.
Is there a reliable method to check for cya in waters with chlorine levels high?
I got a CYA OF 65 with a method I tried. This method is a method to measure CYA when water is high in chlorine. I read about this method in this forum, which is the one you add two drops of the thiosulfate. (2 drops of R-0007)?
I truly do not know if I am correct or not regarding my CYA Levels. I would like to make a good attempt to kill the algae but if my CYA is too high I might need to reduce my water by some 30% before I start to shock process.
Can anyone please help me with my readings problems?
George
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
10,964
Houston, Texas
As far as I know, high FC does not affect the results of the CYA test. Are you using a CYA test where you pour the sample into a view tube until the dot disappears? If so, you can read how to conduct this test in the extended test kit directions thread. If you are using a different testing method for CYA please describe it and we will see if we can help you out.

I see you are using a trichlor product in your pool. 5lbs of trichlor will raise the CYA by 32. It often takes up to a week for recently added CYA to register on a test, so your current CYA may be well over 100.
 

photo2u

Well-known member
Jan 3, 2010
100
Claremont california
zea3 said:
As far as I know, high FC does not affect the results of the CYA test. Are you using a CYA test where you pour the sample into a view tube until the dot disappears? If so, you can read how to conduct this test in the extended test kit directions thread. If you are using a different testing method for CYA please describe it and we will see if we can help you out.

I see you are using a trichlor product in your pool. 5lbs of trichlor will raise the CYA by 32. It often takes up to a week for recently added CYA to register on a test, so your current CYA may be well over 100.
Thank you so much for all the welcomed productive information.
Yes, THEY ( Local Pool Supply Store ), were using a CYA test where you pour the sample into a view tube until the dot disappears?
I just got to say that my local pool is just not that credible anymore. First, the Leslies representatives told me that they could not test my waters due to high level FC. They were particular about CYA and told me that it was no use to test because the high Level of FC will render bad CYA reading. You know what? I believed them! My mistake! Live and learn. At my other local pool supplies their testing skills are just very bad. I got a CYA level of 100 from them?
After reading you post regarding CYA, I decided to test and retest my CYA several times. My results were very constant at 40. My conclusion is that the first 60 CYA reading prior to begin my shock was just not correct. I just do not think that CYA changes that much in two days. Or maybe my regents might be old or bad?
Any ways, I will take water samples to different pool supply store to compare their readings with mine. Hopefully my CYA readings of 40 are correct so that I can properly use the proper amount of liquid Chlorine to shock my pool to kill the muster algae.

Thanks so much for educating me regarding pool maintenance.
George
 

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