High TA fill water

[jmlodin]

We just had our vinyl liner replaced. The fill water has a high TA, so therefore my first numbers are high. I have added bleach.

FC 5
PH 7.4
TA 200
CH 300

I will start adding acid to get the TA down, but would like to know what is a reasonable number to shoot for. I know the recommended level is 70-90, but I am wondering what is an acceptable upper limit. Thanks for your help.

 

[woodyp]

Shoot for 120 to start. Your Ph may be (more) manageable there.

 

[BoDarville]

jmlodin:

TA is a measure of the water's ability to buffer pH changes. Generally speaking, low TA levels tend to cause the pH to fluctuate erratically. High TA usually causes the pH values to drift up. So, the real determining factor when considering the need to adjust TA is, how stable is your pH? Given your current pH of 7.4 (which is fine, BTW), I would keep an eye on it by testing daily over the next week or so. If pH starts drifting up, then you can lower the pH to 7.2 using Muriatic Acid (MA) which will also lower TA. Continue monitoring pH. If it drifts back up towards 7.8, lower it again to 7.2 which will also lower TA even further. Once pH begins to stabilize, you will have found the TA happy medium for your pool.

Another detail to consider. Being in Indianapolis, I'm guessing your swim season either hasn't started or is in its infancy. Once more people begin swimming & splashing on a regular basis, the water will get aerated which causes pH to drift up, perhaps dramatically in a short time. However, the aeration has very little effect on TA. All the more reason to test pH daily for a while in addition to your daily FC testing.

 

[jmlodin]

Thank you for your very detailed reply! Yes it is just the start of swim season here in Indy due to a cold spring. Our TA was running high last summer too and we really did not see a lot of upward drift in our PH. I think I spent too much time trying to lower TA because I thought it had to be at a certain range. So just to be clear....as long as our PH is in a good range I don't really need to be concerned about where our TA is? Thanks again

 

[BoDarville]

So just to be clear....as long as our PH is in a good range I don't really need to be concerned about where our TA is?

As long as your pH is within range and relatively stable, then I wouldn't fiddle with TA, especially since you are not battling a high CH problem. The pH stability is the main key. Between pH and TA, I would consider the pH range to be a hard target and TA as a softer target. So if your pool's pH is in range and stable, I would not adjust TA just to reach a certain number.

 

[jmlodin]

This will make our pool much more "trouble free" if I don't have to mess with muratic acid! I also appreciate you telling me PH of 7.4 is also fine so I don't have to aerate right now either! I am sure like you said it will drift up with people using the pool. Thanks again!

 

[BoDarville]

You're welcome