High TA, low pH

[ncoliver1]

Hello everyone,

I'm a new pool owner. Test kit just came in today, but to this point I've been relying on the pool store. My water has low pH and high TA. Pool store told me to buy and add soda ash and then muriatic acid. Seems pretty counter productive to me. I see the pool math app says to use acid to bring pH to about 7.2 and aerate the water. As pH rises add more acid to reduct TA and repeat the process. I bought 2 PVC fountains that attach where the jets were off of Amazon. Any idea how long it would take to raise pH doing this? It's a 41,000 gallon pool.

Thanks,
Nick

 

[magiteck]

Can you post up a full set of test results from your new kit?

Low pH and high TA are typically not compatible, so I'd like to see what your actual numbers are.

I would not add any acid or soda ash at this time, until we confirm.

 

[ncoliver1]

Pool Store numbers came back at
Total chlorine 2.89
Free Chlorine 2.71
pH 7.0
Alkalinity 159
CYA 56

I tested using the Taylor K-2006C about 4 days later. I had added some muriatic acid and started aerating already.
I got
Free chlorine 4.6
combined chlorine .8
pH 7.0
Alkalinity 180
Hardness 200

 

[an1vrsy]

Good job getting one of the recommended test kits. Did you get the speed stirrer? It makes test easier as you would not be swirling by hand.

You‘ll have check your pH to see how it is rising. When kit gets to 8.0 using pool math add enough MA to lower it pH to 7.2 that will lower a good chunk out of your TA. Then repeat.

what is your CYA? You’ll want to make sure you’re following the FC/CYA chart to keep your FC levels at your target or above.

 

[ncoliver1]

Good job getting one of the recommended test kits. Did you get the speed stirrer? It makes test easier as you would not be swirling by hand.

You‘ll have check your pH to see how it is rising. When kit gets to 8.0 using pool math add enough MA to lower it pH to 7.2 that will lower a good chunk out of your TA. Then repeat.

what is your CYA? You’ll want to make sure you’re following the FC/CYA chart to keep your FC levels at your target or above.

Didn't get the speed stirrer, maybe next time. CYA was 50. Thought I typed it in the other response, but must have forgot as I'm also grilling and sipping some bourbon.

 

[ncoliver1]

Good job getting one of the recommended test kits. Did you get the speed stirrer? It makes test easier as you would not be swirling by hand.

You‘ll have check your pH to see how it is rising. When kit gets to 8.0 using pool math add enough MA to lower it pH to 7.2 that will lower a good chunk out of your TA. Then repeat.

what is your CYA? You’ll want to make sure you’re following the FC/CYA chart to keep your FC levels at your target or above.

When I'm doing the test, when it has me add drops until it changes color do I stop at the first sign of color change or once it's a full change? I might have added to many drops on a few messing up my numbers as I kept going until it was full blue or full red not just first sign of color change.

 

[an1vrsy]

For the TA test, you will see a change to light red, 11th drop. then the next drop 12th will be a deeper red, the next drop 13th doesn’t change the color anymore. So that last drop 13th doesn’t count. In this scenario the TA would be 120.

 

[magiteck]

How are you chlorinating?

 

[ncoliver1]

I did my first shock with dichlor and after finding this website it's been liquid chlorine ever since.

 

[magiteck]

Since you’re using Liquid Chlorine, you’re not unintentionally introducing acid to your pool.

I wouldn’t worry about your TA. It’s a bit high, and that will have the effect of encouraging your pH to drift up on its own. It’s not hurting anything by itself.

For pH, generally anything between 7-8 is fine. So with your pH of 7, I would do nothing. Keep testing and you should see it increase over time. If/when it gets to 7.8-8, then you can add muriatic acid to lower it back down to ~ 7.2. Over time, that will also bring your TA down, which will lengthen the amount of time it takes for your pH to drift back up.

In short, manage the pH, and the TA will naturally follow in time.

 

[ncoliver1]

Since you’re using Liquid Chlorine, you’re not unintentionally introducing acid to your pool.

I wouldn’t worry about your TA. It’s a bit high, and that will have the effect of encouraging your pH to drift up on its own. It’s not hurting anything by itself.

For pH, generally anything between 7-8 is fine. So with your pH of 7, I would do nothing. Keep testing and you should see it increase over time. If/when it gets to 7.8-8, then you can add muriatic acid to lower it back down to ~ 7.2. Over time, that will also bring your TA down, which will lengthen the amount of time it takes for your pH to drift back up.

In short, manage the pH, and the TA will naturally follow in time.

Perfect. Thank you.

 

[pjt]

Free chlorine 4.6

Use the 10 ml sample so each drop is 0.5 FC. Saves time and reagents.