TA

[TexasFrost]

So I need to reduce my TA by 130ppm. I am going to use the acid/aeration method that Trouble Free suggests. How often should I add acid (intervals)? I don't want to damage the pool or equipment. Can I do this (acid/aeration) every three hours or at a faster rate or slower rate? I'm a newbie!

Thanks

 

[Richard320]

How often depends entirely on how fast the pH rises. And that depends a lot on how vigorous the aeration is. The only way you'll know is by testing.

Question for you: Why? Do you suffer from one of these conditions?

There are two reasons to lower your total alkalinity (TA) right away, because you want to slow down the rate that the PH rises, or if high TA is contributing to a high calcium saturation index (CSI) which puts you at risk of calcium scaling. You shouldn't lower TA just to reach a target number. Make sure you actually have one of the above issues before lowering your TA.

What are the rest of your test results? If you have low CH, dropping the TA could actually lead to a negative CSI, which is rough on plaster. Just maintaining the pH for a long period of time should bring TA down without any special effort beyond normal testing and maintenance.

 

[Butterfly]

The amount of time it will take will depend mainly on how much aeration you have. More aeration will raise pH faster and therefore you'll be able to add acid more often.

 

[TexasFrost]

All of my other levels are good. It is my PH that is consistently high. So after adding acid, how long should I wait to take a reading on PH? My TA is at 210. Everything says that I have to lower it to 80. I appreciate any feedback.

 

[Richard320]

All of my other levels are good. It is my PH that is consistently high. So after adding acid, how long should I wait to take a reading on PH? My TA is at 210. Everything says that I have to lower it to 80. I appreciate any feedback.

"Good" is rather a subjective term. Have you been plugging ALL your test results into poolmath? Because you should, and see what the CSI calculation says in the Target column when you've plugged in your desired results. Maybe you don't want it all the way down to 80?

That said, I'd dose it with acid to get it to 7.2. Test pH again in two hours and see where you're at. If it's crept up to where you think you need to add acid again, note that you will need to test TA as well, because that affects the calculations for the acid dose. If it's only up to 7.4, give it another couple hours. Be aware that the time to drop the first, say, 20 ppm will be less than the next 20 and so on.

Also, if it's a new test kit, you may be suffering from static buildup on the tip of the TA reagent bottle, which causes smaller than normal drops, which makes it take more drops to get the same color change, which will throw off your TA reading. http://www.troublefreepool.com/threads/62711-Why-the-need-to-wipe-between-drops-when-testing-for-TA