Water cleared, low readings

dw9000

Well-known member
Aug 17, 2014
199
NW Ohio
I took a pH and FC sample, had almost no chlorine and about 7.8 to 8 pH. I added 2 gals of bleach. I took a reading 6 hrs later and the FC was up to about 4.
Today I took another reading, and the FC is close to 1. I took the CYA,, and it is about 26 (according to the black dot test).

According to the poolmath calculator, I need to add about 106 ounces liquid CYA and 1.5 bottles of bleach. Does it matter in which order and does one have to sit before adding the other?

Thanks in advance
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,930
San Dimas, CA (LA County)
I took a pH and FC sample, had almost no chlorine and about 7.8 to 8 pH. I added 2 gals of bleach. I took a reading 6 hrs later and the FC was up to about 4.
Today I took another reading, and the FC is close to 1. I took the CYA,, and it is about 26 (according to the black dot test).

According to the poolmath calculator, I need to add about 106 ounces liquid CYA and 1.5 bottles of bleach. Does it matter in which order and does one have to sit before adding the other?

Thanks in advance
Add the CYA first, because the higher CYA means you will need to target a higher FC. The liquid stuff will be active within minutes, certainly within hours, so you need to use the estimated CYA value as the now value and set the FC target accordingly.
 

dw9000

Well-known member
Aug 17, 2014
199
NW Ohio
Add the CYA first, because the higher CYA means you will need to target a higher FC. The liquid stuff will be active within minutes, certainly within hours, so you need to use the estimated CYA value as the now value and set the FC target accordingly.
Great thanks, that liquid CYA is kind of pricey,,, does this powder/crystal look ok? According to the amazon reviews, it is 100% cya I can use a sock and wait a bit longer....
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Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
The powder is fine, we suggest you hang it in an old sock in front of the return as it is very acidic and dissolves very slowly
 

dw9000

Well-known member
Aug 17, 2014
199
NW Ohio
So do you suggest I add the CYA (hanging a sock in front of a return)? Let it all dissolve? Retest in a couple days,, then add the chlorine?
 

PAGirl

TFP Guide
Jun 5, 2012
2,390
Central PA
So do you suggest I add the CYA (hanging a sock in front of a return)? Let it all dissolve? Retest in a couple days,, then add the chlorine?
You can add your chlorine while the CYA is hanging. Once it is all dissolved, dose your chlorine at the target CYA value. It may not show up on the CYA test right away, but it will be working. You should always keep your chlorine above the minimum for your CYA.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
47,004
Tallahassee, FL
The chlorine needs to be added now to keep the water from going green. Chlorine and CYA work together very well. Target your FC as if the CYA is already in the pool.

Kim