Issue with CYA levels

coldaf

Member
Jul 8, 2019
7
New York
Hello I have recently purchased the Taylor Technologies K-2006 test kit and ran some tests on my pool water.

The results came back as follows:
CYA: less than 30 ppm
FC: 0.2 ppm
PH: 7.8
TA: 60 ppm
Calcium hardness: 70 ppm

Having read through some of the threads on this forum I came to the conclusion that the first thing I needed to fix was the CYA levels.
I began by adding two bottles of "Clorox Pool&Spa Pool Chlorine Stabilizer, 4 lbs" to my 30,000 via a sock tied to our ladder. One week later I tested the pool water gain for CYA and the results still show CYA less than 30 ppm. I then proceeded to add another bottle of "Clorox Pool&Spa Pool Chlorine Stabilizer, 4 lbs" in the same manner. Four days later I tested the CYA again and the results still show less than 30 ppm.

I am at a complete loss right now as to what is going on with the CYA levels. According to the directions on the stabilizer, the amount I added to my pool should have raised the CYA by 45ppm. I am unsure if the test results are inaccurate or if my CYA levels are truly too low to measure.

If any one has any experience with this situation or any insight it would be greatly appreciated. I am hesitant to add more stabilizer to the pool because if the results ARE inaccurate I have heard it is quite hard to lower CYA.

PS: Once the pool water and the cya reagent are mixed it is barely cloudy and I can fill the entire test tube to the top without the black dot disappearing.
 

coldaf

Member
Jul 8, 2019
7
New York
Welcome to the forum!
Do not add any more CYA for now.
What does the pool water look like? I see no FC. Are you adding chlorine every day? How are you doing that?
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.
Thank you for your warm welcome!
The pool water is clear and blue. I am adding chlorine on a weekly basis via two gallon of "Pool Essentials Chlorinating Liquid," as well as the constant use of Chlorox chlorine tablets via a floater. Since the FC levels do not stay at their appropriate levels. I figured that my FC was being eaten up by the sun and my CYA was too low, therefore I needed to raise the CYA levels before FC can be maintained.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,961
Laughlin, NV
As you are adding CYA with the tablets too, it is concerning you are not seeing the CYA level.

Do me a favor, add enough liquid chlorine to get to 10 ppm in your pool. Circulate the pool for 15 minutes. Test the FC and CC. Report those back here.
 

coldaf

Member
Jul 8, 2019
7
New York
As you are adding CYA with the tablets too, it is concerning you are not seeing the CYA level.

Do me a favor, add enough liquid chlorine to get to 10 ppm in your pool. Circulate the pool for 15 minutes. Test the FC and CC. Report those back here.
I will go ahead and pour 3 gallons of "Pool Essentials Chlorinating Liquid" into my pool tonight, which should be enough to raise the chlorine levels to roughly 10 ppm. After 15 minutes of circulation I will get back to you with the FC and CC levels.
 

coldaf

Member
Jul 8, 2019
7
New York
As you are adding CYA with the tablets too, it is concerning you are not seeing the CYA level.

Do me a favor, add enough liquid chlorine to get to 10 ppm in your pool. Circulate the pool for 15 minutes. Test the FC and CC. Report those back here.
Last night at around 8pm I went ahead and poured 3 gallons of "Pool Essentials Chlorinating Liquid" into my pool. According to the packaging that should be enough to raise my pool's FC to 10 ppm. After 20 minutes with the pump running I tested the pool water and got the following results:
FC: 2.0 ppm
CC: 1.0 ppm
PH: 7.0

Very strange that the FC raised so little. Also worth noting that the PH of the pool went down .08 without the addition of any PH reducer. This may have something to do with the CYA that I added previously?

Regardless, I tested the pool water again at 5:30am just as the sun was rising. The results were the same, so it seems that the FC is not being eaten up overnight by organic matter. As for how it will fair after a day in the sun, I can update later.

As for the CYA, I did not perform a test yesterday as I ran out of the reagent, but have since ordered more.

Would you advise that I try to once again get the FC higher?
 

IceShadow

Gold Supporter
Jun 8, 2019
1,072
Milwaukee, WI
I would recommend continuing to chlorinate to 10 ppm - you may be fighting ammonia. (There's a bacteria that consumes CYA and turns it into ammonia.) That you still have 2ppm left is a little odd as, as far as I understand it, ammonia will consume all of the chlorine, but perhaps you had just barely broken through it and 2ppm was left over?

The best way to get rid of the ammonia (and any bacteria that may be causing it) is by adding chlorine to 10ppm, circulate for 15 mins, re-test, re-add to 10ppm, repeat until you hold 5ppm FC or higher on the re-test.

@mknauss - what do you think?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,961
Laughlin, NV
Very low CC for ammonia. Also still tested FC of 2 after overnight. So not ammonia.

You said the pool was filled 4 months ago. How did you chlorinate the past 4 months?
 

coldaf

Member
Jul 8, 2019
7
New York
Very low CC for ammonia. Also still tested FC of 2 after overnight. So not ammonia.

You said the pool was filled 4 months ago. How did you chlorinate the past 4 months?
There was a constant usage of chlorine pucks, along with weekly chlorination. Previously the weekly chlorination was the powdered form, but I have recently switched to the liquid form.
 

coldaf

Member
Jul 8, 2019
7
New York
So you had added a lot of CYA with the pucks and possibly the powder.

Where did it go?
That is where my confusion comes in. Based on all the factors I should have at least 40ppm CYA, yet when I run the Taylor test for CYA results show that it is lower than 30ppm.
Very unsure as to what the root of this issue is.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
22,961
Laughlin, NV
Well -- best case is to follow the SLAM Process. Or drain a large amount of water and start over. Something is not right.

Can you fill out your signature so we know pool type, etc?