What happened? FC 2; CC 12.3

[Yunfeng]

Initial test results before adding chlorination liquid

FC 0
CC 0
TA 180
pH 7.0
CYA 0

It was suggested to perform 10min 10ppm FC lost test, so I started to pour chlorination liquid 2 gal/time to my pool (estimated as 17000 gallon). Since each 10min test showed that FC did not reach 5 ppm, I keep adding liquid to the pool at same pace. After 8 gallon chlorination liquid added within 4-5 hours, I had new test results

FC 2
CC 12.3
other did not test.

What should I do now? Thank you in advance.

 

[JamesW]

You need the SLAM process. You might have ammonia.

If you had CYA at closing, bacteria might have eaten the CYA and converted it into ammonia.

Oxidizing ammonia is acidic. So, if you are fighting ammonia, you will see the pH and TA drop as you go through the SLAM process.

What was the CYA at closing?

Pool School - SLAM - Shock Level And Maintain

 

[Yunfeng]

You need the SLAM process. You might have ammonia.

If you had CYA at closing, bacteria might have eaten the CYA and converted it into ammonia.

Oxidizing ammonia is acidic. So, if you are fighting ammonia, you will see the pH and TA drop as you go through the SLAM process.

What was the CYA at closing?

Pool School - SLAM - Shock Level And Maintain

Hi, James, Thank you for your response.
I am the new owner of the pool, so I don't know anything about the closing last fall. I also don't know the basic information about the pool size.
If I proceed the SLAM, I need to start adding CYA to the pool, which may take at least two days to reach suggested 30 ppm. During this time window, should I keep adding chlorination to maintain FC at 10 ppm, or I can leave it for now until CYA goes up?

 

[JimMarshall]

Hi, James, Thank you for your response.
I am the new owner of the pool, so I don't know anything about the closing last fall. I also don't know the basic information about the pool size.
If I proceed the SLAM, I need to start adding CYA to the pool, which may take at least two days to reach suggested 30 ppm. During this time window, should I keep adding chlorination to maintain FC at 10 ppm, or I can leave it for now until CYA goes up?

You need to get to where you can keep FC before you add CYA. If you are battling ammonia, adding CYA before it’s all oxidized will just creat more ammonia.

Continue testing. You need to be able to dose your pool to 10 PPM FC, wait 10 minutes, and have a minimum of 5 PPM left after 10 minutes before we add any CYA to that pool.

How big is the pool? Length x width x depth? Or is it free form?

 

[Yunfeng]

You need to get to where you can keep FC before you add CYA. If you are battling ammonia, adding CYA before it’s all oxidized will just created more CYA.

Continue testing. You need to be able to dose your pool to 10 PPM FC, wait 10 minutes, and have a minimum of 5 PPM left after 10 minutes before we add any CYA to that pool.

How big is the pool? Length x width x depth? Or is it free form?

Thank you very much. I am following your instructions. So far, my pool has passed the 'double 10' FC test-with FC at 7 ppm at 15 mins and 5 ppm at 30 mins. I didn't perform CC test since I am afraid I will run out of the reagent in the poor brown little bottle for this. I have put the CYA in socks and hung it in front of the returning. Just for curiosity, if it takes three times higher of concentration of FC to break down CC, does that mean I have to increase FC in my pool to 60 ppm, let's assume, the CC can go up to 20?

As for the shape of my pool, please see the image and do give some advice to determine the volume.

 

[JimMarshall]

Thank you very much. I am following your instructions. So far, my pool has passed the 'double 10' FC test-with FC at 7 ppm at 15 mins and 5 ppm at 30 mins. I didn't perform CC test since I am afraid I will run out of the reagent in the poor brown little bottle for this. I have put the CYA in socks and hung it in front of the returning. Just for curiosity, if it takes three times higher of concentration of FC to break down CC, does that mean I have to increase FC in my pool to 60 ppm, let's assume, the CC can go up to 20?

As for the shape of my pool, please see the image and do give some advice to determine the volume.View attachment 79322

Im not sure what you mean by the 3x concentration or where that came from....

if your pool has been there a while you can use the measuring tool at findlotsize.com to find the surface area of your pool and then multiply by the average depth to get approximate volume