High PH, low TA, and low CYA on opening -- order to add chemicals

[al27]

I need some advice on the order to add the necessary chemicals to start a SLAM. Here are my latest test results, after running the pump for 24 hours.

FC - 0
CC - .5 (how is this possible since water is green?)
TA - 40-50 (turns kinda purple at 40, red at 50)
PH - 8.3 (its a purple-pink color)
CYA - 20-30

I know that I need to add muriatic acid to lower the PH, baking soda to increase the alkalinity, and may need to add some CYA. I'm going to confirm the CYA level at a pool store since I'm terrible at interpreting the CYA test. If CYA ends up being 20, I will use liquid CYA to increase the CYA to 30 since I have some on hand already.

Since I need to add muriatic acid, baking soda, and liquid CYA to the pool, I need to know which one to add first, which one to add second, and which one to add third and how long I should run the pump before adding each one.

 

[ajw22]

Don’t touch your TA. 50 is fine.

Go gentle on lowering your pH slowly to no more then 7.8

Focus on your chlorine and CYA. That is priority 1. Add them both together and run your pump.

 

[al27]

Don’t touch your TA. 50 is fine.

Go gentle on lowering your pH slowly to no more then 7.8

Focus on your chlorine and CYA. That is priority 1. Add them both together and run your pump.

Are you saying that I only need to lower PH to 7.8 instead of lowering PH to 7.4? If the muriatic acid lowers the TA to 40, should I add baking soda to increase it? If so, what TA number should I shoot for?

I tested my CYA again and I think it is around 20 instead of 30 because I can kinda make out the dot at 30. If I add some liquid stabilizer to get it to 30, can I add the liquid CYA and then start the SLAM an hour later?

 

[ajw22]

Are you saying that I only need to lower PH to 7.8 instead of lowering PH to 7.4?

Yes.

If the muriatic acid lowers the TA to 40, should I add baking soda to increase it?

No, if you have high pH then your TA is fine. Low pH and TA is reason for some action.

If so, what TA number should I shoot for?

Let your TA find its natural equilibrium with your pH as long as your pH stays in the high 7's.

Don't shoot for a TA number. Let it find it naturally.

I tested my CYA again and I think it is around 20 instead of 30 because I can kinda make out the dot at 30. If I add some liquid stabilizer to get it to 30, can I add the liquid CYA and then start the SLAM an hour later?

Add the stabilizer and begin the SLAM with raising your FC right after. Assume the stabilizer you added is in the pool.

 

[al27]

Yes.



No, if you have high pH then your TA is fine. Low pH and TA is reason for some action.



Let your TA find its natural equilibrium with your pH as long as your pH stays in the high 7's.

Don't shoot for a TA number. Let it find it naturally.



Add the stabilizer and begin the SLAM with raising your FC right after. Assume the stabilizer you added is in the pool.

I tried to lower the PH last night to 7.8 with muriatic acid like you recommended but the color of the sample is still much darker than 8.2. I added enough to lower the PH from 8.2 to 7.8 according to the pool math calculator. I took a sample to a pool store and they are saying that the PH is 8.7 now. Their test showed that the TA is 47 and CYA is 16. I know that the pros on here don't have much faith in pool store testing, but I don't know how to get an accurate PH reading with the Taylor test kit that I have. Is there an easy way to get an accurate PH reading with my Taylor test kit or do I assume that the pool store is correct about the PH being 8.7 and dose the muriatic acid accordingly? If the TA is 47 like pool store testing suggests, do I need to add any baking soda if the muriatic acid lowers the TA to 40 or below?

 

[mknauss]

It is chemically not possible to have a pH of 8.7 and a TA of 47. The pH/TA balance would max out the pH at about 8.3.

 

[al27]

The PH sample is a dark pinkish/purple so I know the PH is above 8.2. When I test the alkalinity, the sample turns kinda purple at 4 drops and bright red at 5 drops. I took water samples to 2 pool stores and both pool stores say that the PH is 8.7. Both pool stores also said that the TA is between 45-47. Based on this, I assume that the pool stores are correct about the PH being higher than 8.2 and the TA being 47. When I retested the PH after adding muriatic acid, the color of the sample didn't change much, so I have a feeling that the PH is much higher than 8.2. Testing chemicals are brand new BTW. How am I supposed to figure out how much more muriatic acid to add? Muriatic acid kinda scares me so I don't want to keep adding small amounts over and over again until I hit the 7.8 target. I also worry that it is going to lower the TA to 40. If this happens, do I need to add baking soda or just start the SLAM with a TA of 40?