Trying to Adjust TA

phalcon51

0
LifeTime Supporter
Oct 5, 2010
203
So. California
My TA was a little high (about 90-100). Following the recommendations in the Pool Calculator I lowered the pH to 7.0 and began aerating the pool on Sunday evening. Yesterday morning the pH was 7.2 and today it's 7.4, but the TA went from 70 yesterday to 80 today. I understand that 80 is an OK level for TA, but is it normal for it to climb back up so fast? I thought the low pH brought down the TA and the aeration was supposed to cause the pH to rise but leave the TA alone. Is it likely to stabilize at some level below where it was to start with? Do I need to keep the pH at a lower level for a while, or just let it rise on its own to the normal range?

Thanks

Gary
 
The change in TA is either test error (one drop is 10 ppm) or small variation in the TA in different parts of the pool. Basically, when you add acid again to lower the pH back down to 7.0, the TA will get lowered. Continued cycling of aeration and acid addition will continue to lower the TA.

If you're OK with 80, then you can just let the pH rise from aeration or on its own. If you want the TA to be lower than that, then continue the aeration and acid addition process.
 
Thanks Chem Geek.

I'm OK with a TA of 80 so I'll just let the pH rise on its own till it gets to the normal range. I suppose the TA difference could be due to testing error, but I'm pretty meticulous about it. I always pull the water from the same spot in the pool and the same depth at the same time of day. I'm very careful to have exactly the right amount of water in the sample vial and put in the drops from a vertical bottle to try and make everything consistent. I'm also using a SpeedStir, but I suppose there can still be variations.

Gary
 
phalcon51 said:
I'm also using a SpeedStir, but I suppose there can still be variations.

Gary


No doubt you can see variation of +/- 10, so it's not just you, but that said it is more than accurate enough and far more precise than test strip results tend to be interpreted. Your plan sounds just right :goodjob:
 
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