pH and TA problem

[Brian T]

I'm having problems finding the right balance between my pH and TA. I have been adding MA every 2-3 days to get to pH level of 7.6 ppm. People on the forum have told me that the reason why I'm adding MA frequently is because my pool is new and the plaster is still setting.

Well, my TA was initially at 90 and now it is 50. I am about to add baking soda to increase my TA from 50 to 70. I go to the pool calculator to figure out how much baking soda to add and the site tells me that I need to lower my pH to 7.0-7.2 before lowering TA.

1. Is this true?

2. Let's say that I bring my TA up to 70 and my pH eventually drops. I add MA to get pH to proper levels and my TA drops again. How do I avoid this annoying cycle?

By the way, my FC, CH and CYA are within normal range.

 

[duraleigh]

and the site tells me that I need to lower my pH to 7.0-7.2 before lowering TA.

I think you are mixing that advice from another process. You do not need to have your pH in that 7.0 - 7.2 range to raise TA.

If that was my pool I would not raise the TA but just leave it and observe.

TA and pH and the relationship will always be the hardest to get straight in pool management. I post this from time to time to help....

pH up - 20 mule team borax

pH down - Muriatic acid

TA up - Baking soda

TA down - aeration and acid...it's a process found in Pool School that you must read to make TA down change quickly and permanently

 

[Brian T]

Yes, I have read pool school thoroughly, in my opinion. I have spent a lot of time on this forum and did run across a few threads on this topic.

I just did a test and my TA is 50 and my pH is 8.0...Would your advice be to continue to add MA, even if it will further bring my TA down?

- - - Updated - - -

I think you are mixing that advice from another process. You do not need to have your pH in that 7.0 - 7.2 range to raise TA.

If that was my pool I would not raise the TA but just leave it and observe.

TA and pH and the relationship will always be the hardest to get straight in pool management. I post this from time to time to help....

pH up - 20 mule team borax

pH down - Muriatic acid

TA up - Baking soda

TA down - aeration and acid...it's a process found in Pool School that you must read to make TA down change quickly and permanently

I am reading those instructions directly from the pool calculator.

 

[swoopman]

I think it's just some confusion on what the pool calculator is saying since some people need to raise TA and some need to lower TA. The pool calculators says:

Add __ by weight or ___ by volume of baking soda.
To lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH.

The first line is what to do if you are raising TA and the calculator fills in the recommended amount.

The second line is the directions of what to do if you need to lower TA. So you only are lowering pH (followed by aeration) when you are lowering TA, not raising it.

 

[Brian T]

Thank you. I'm getting confused. I wanted to raise my TA and read that and then somehow, my brain made me think that I wanted to lower my TA.

Anyways, does anyone have any advice on whether I should increase my TA from 50 to 70 or leave it at 50 and continue to add MA to bring pH to at least 7.8? I don't know which one I should adjust. Thanks

 

[duraleigh]

Now that I understand your pH, I would lower it to around 7.5 or so. That will also simultaneously drop your TA further so then test and bring TA back up to around 70 (with baking soda) and you should be good to go.

 

[swoopman]

You're welcome. Glad to help.

 

[cwritner]

Having basically the same issue. High TA. PH goes out of range (too high) by the end of the week. My TA is at 160 and PH is 7.6. I just continue to add MA. I have 18000 gallon indoor pool. No sunlight. Using a SWG. Really pleased with clarity and feel of water. Any suggestions on how to lower TA drastically?


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[Brian T]

Before I say anything, just wanted to let you know that I'm a new pool owner. In my opinion, I think you should continue to add MA when needed to lower your pH to the proper level. Be patient. The TA will lower. It's just a matter of time. With a high TA of yours, I believe the pH will fluctuate more.

By the way, we don't have the same issue. My TA is low at 50. I just added baking soda and brought it to 80. I was surprised to see that my pH did not go up too much. I hope I'm on my way to where the pH and the TA can "coexist" and become stable so that I don't have to continue to add MA (to correct pH) so frequently.

 

[chem geek]

Every 46 fluid ounces (5.75 cups) of full-strength Muriatic Acid (31.45% Hydrochloric Acid) in 18,000 gallons will lower the TA by 10 ppm so over time if you add acid to lower the pH the TA should drop unless you have a lot of evaporation and refill with water high in TA. If you want to lower the TA more quickly, then you can add acid at low pH with aeration as described in the Pool School article on how to Lower Total Alkalinity. It simply accelerates the natural process of what happens when you add acid over time. The aeration and low pH accelerate the carbon dioxide outgassing.