Can I start adding CYA if my chlorine level is 15?

roycehi@aol.com

Active member
May 31, 2010
35
Honolulu, Hawaii
I have a black algae problem and so I raised the chlorine level to combat it. However I forgot to test the CYA level. When I did it seems to be 0 (not a test I have a lot of faith in). The CYA manufacturer recommends a chlorine level of 1-4 before beginning. Is that really necessary? If so I guess I'll have to get a chlorine lowering product. I hope to hear back soon as the black algae is going to town!

saltwater pool
CL 15
CC 1
pH 7.4
CH 270
TA 100
water clear
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,278
Northern NJ
You can add stabilizer with any chlorine level. You don’t need to lower chlorine.

Add 30 ppm of stabilizer using the sock method.


Solid/granular cyanuric acid (CYA) should be placed in a sock and the sock put in the skimmer basket or suspended in front of a pool return. After adding CYA you should leave the pump running for 24 hours and not backwash/clean the filter for a week. Squeezing the sock periodically will help it to dissolve faster. Test and dose chemicals in your pool assuming the amount of CYA added is in the pool according to Poolmath. CYA can be tested the day after it is fully dissolved from the sock.

 

duraleigh

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Apr 1, 2007
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Sebring, Florida
Is that a starting point so I don't add too much?
No. 30 ppm is a reasonable level to perform the SLAM process and get your pool clear. 70 ppm or so comes after your SLAM is complete, the black algae gone, and you are in maintenance mode.

Black algae is often misdiagnosed.......do you have a pic?
 

duraleigh

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Sure sounds like black algae, then. It will take not only the SLAM process but then some follow up with a wire brush and elevated chlorine if you wish to get rid of it.
 

Etchase

Active member
May 22, 2019
33
Hawaii
I was thinking of tiling to permanently eradicate my black algae problem. Guess not. I was wondering if it came back just in the grout or on the tile too? Do you think it is a new outbreak or is it reoccurring in the same areas that it was a problem on the plaster. Tough problem.
 

roycehi@aol.com

Active member
May 31, 2010
35
Honolulu, Hawaii
Thanks again. I am worried though about using a wire brush on tile. No one seems to consider tile when they talk about pool surfaces. On the pool calculator I use plaster as the closest choice. And I did read TFP's write up on black algae ( and several others) . That's my starting point.
 

Etchase

Active member
May 22, 2019
33
Hawaii
Mine comes back in about a year too. I’m going to try using a pressure washer underwater next time. Have no idea if that will work, but it works well when the pool is empty. Good luck.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,278
Northern NJ
Thanks again. I am worried though about using a wire brush on tile. No one seems to consider tile when they talk about pool surfaces. On the pool calculator I use plaster as the closest choice. And I did read TFP's write up on black algae ( and several others) . That's my starting point.

A tile pool is considered a plaster pool for water chemistry purposes.
 

duraleigh

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I can also add that black algae typically occurs in pools with chronic low chlorine issues. You both can clear your pool once and for all if you are willing to practice the methodology TFP teaches. This is Royce's thread so, Etchase, if you have further questions, please start your own new thread and we'll all help get you both crystal clear.
 
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