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Hi,

I've been wondering, does increasing pH with NaOH also increase TA?

Thank you

[Edit]

Already found my answer in pool calculator.

Yes it does raise the TA.

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But i did notice that using NaOH to raise pH, does not raise TA as much as soda would. So raising pH with NaOH when TA is already at recommended level would be better?

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If you want to raise the pH with no change in TA, then aerate the water. And yes, raising the pH using lye (NaOH) or using 20 Mule Team Borax raises the TA by about half as much as using pH Up (sodium carbonate).

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I have a consistent problem with my spa water treatment.  My starting water has Calcium Hardness of 55ppm and pH of 6.8.  I raise the Calcium Hardness to 300+ppm.  This leaves the water with good Total Alkalinity of 80-120ppm - perfect.  So I then correct the pH upward incrementally by adding Sodium Carbonate.  As I add each 1-1.5oz increment of Sodium Carbonate, the Total Alkalinity moves up and the Calcium Hardness goes down, and the water gets cloudy for several hours.  I assume the cloudiness is due to Calcium precipitate of some kind.  I assume that the precipitate is filtered out or sticks to spa surfaces.  Once the pH is above 7.2, the Total Alkalinity is above 120ppm and the CALCIUM HARDNESS IS LOWER THAN IT STARTED AT BELOW 55PPM!!!  I then start over and raise the calcium hardness again and then have to raise the pH again, which has dropped to 6.8-7.0.  Then the Calcium Hardness goes back down and the alkalinity goes up.  IT IS A VICIOUS CIRCLE!!  Should I be using something else to keep the Calcium in solution, or should I try SODIUM HYDROXIDE TO RAISE THE pH INSTEAD?  I use a digital meter to get my readings, so judgement of colors on sticks is eliminated.  PLEASE HELP.

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On 12/30/2019 at 11:54 AM, Bobs_spa said:

I have a consistent problem with my spa water treatment.  My starting water has Calcium Hardness of 55ppm and pH of 6.8.  I raise the Calcium Hardness to 300+ppm.  This leaves the water with good Total Alkalinity of 80-120ppm - perfect.  So I then correct the pH upward incrementally by adding Sodium Carbonate.  As I add each 1-1.5oz increment of Sodium Carbonate, the Total Alkalinity moves up and the Calcium Hardness goes down, and the water gets cloudy for several hours.  I assume the cloudiness is due to Calcium precipitate of some kind.  I assume that the precipitate is filtered out or sticks to spa surfaces.  Once the pH is above 7.2, the Total Alkalinity is above 120ppm and the CALCIUM HARDNESS IS LOWER THAN IT STARTED AT BELOW 55PPM!!!  I then start over and raise the calcium hardness again and then have to raise the pH again, which has dropped to 6.8-7.0.  Then the Calcium Hardness goes back down and the alkalinity goes up.  IT IS A VICIOUS CIRCLE!!  Should I be using something else to keep the Calcium in solution, or should I try SODIUM HYDROXIDE TO RAISE THE pH INSTEAD?  I use a digital meter to get my readings, so judgement of colors on sticks is eliminated.  PLEASE HELP.

You should always start with your Alkalinity first not Calcium. Also I like 200 ppm calcium for pool and spa water due to the calcium that is already in chlorine. It will stack over time. Yes carbonate will make the water cloudy takes a day to clear most of the time. PH moves very fast with carbonate than with Bi-carbonate. So I generally will stick with the bicarb because it moves them together unlike Carbonate in small bodies of water. Also note that sodium hydroxide (Caustic Soda or Lye) has a PH of 14 so be careful.

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