High TA Confusion

[Neal]

This spring we had our gunite pool re-plastered with hydrazzo. Upon completion, about three weeks ago, we immediately had the pool filled with water by delivery truck. I use the TF-100 test kit and have everything in balance except the TA is high at about 190-200. It started at 240, so it has come down a bit, but I need to get it down further. I have been following the procedure to lower TA from the pool school instructions. I just added another gallon of muriatic acid to get the Ph to 7.0. I have my waterfall, jets and fountain running to create aeration. My understanding is that adding the acid will lower both the TA and Ph? I originally thought that the aeration eliminated the high TA, but now in reading it sounds like this is simply to increase the Ph without increasing TA. Frankly, I tend not to have a problem with Ph being low. In fact with the new plaster and the SWG creating liquid chlorine I generally add muriatic acid a couple of times a week to keep my Ph in balance and from being too high. So, I am a bit confused. Is the acid the only thing I need to lower TA and the aeration is not necessary as long as my Ph is good?

 

[mknauss]

So there is no real reason to aggressively drop TA unless you have a potential for calcium scale. And that is not likely with a fresh fill.

When you add muriatic acid, it drops the pH and consumes some TA. As you aerate you off-gas CO2 and your pH rises. Then you add more acid to drop your pH and that reduces your TA.

So just manage your pH. The TA will drop over time. No real reason to run all the water features unless you like too!

Take care.

 

[Neal]

Great, thanks for the reply. Since refilling the pool after the new hydrazzo I seem to have ever increasing Ph, more than in previous years. So, I add acid to lower it. The reason I mention this is that I read high TA can cause Ph to increase. Is this true? I have also read that the new hydrazzo plaster can cause high Ph. Any thoughts on this??