TA too high for borates?

[Enumjon]

Hi all,

I have been working for a year to get my water levels under control following a drain-refill thanks to the previous owners puck habits. Our fill water has extremely high CA and TA levels. Thanks to refilling with softened water the CA level is now acceptable (500). However, I continue to struggle with TA. Last year I could bring it down to about 120, but then refilling would bring the level up again. Acid-aerate-repeat all summer had no net improvement once I got to the 120-150 range, since the 500 TA fill water kept is rising.

One reason the aeration cycle was not that effective was because the pH took a week to rise from 7.2 to 7.6. In hindsight, was this telling me that my pool was very happy with a TA in the 130 range? Reading over the past few weeks many experts say to not worry about a number, but look for pH stability. My pool seems stable in the 120-150 range.

That being the case, if I add borates is my TA going to go through the roof since I won't be adding 1-2 gallons of acid each week?

 

[JamesW]

In my opinion, you can add borates any time you want without regard to the TA.

I would focus on the CSI and keep it between -0.3 and 0.0.

In general, I'm not a big fan of borates or against them, but if you are going to add them, I recommend boric acid.

 

[mgtfp]

That being the case, if I add borates is my TA going to go through the roof since I won't be adding 1-2 gallons of acid each week?

The total required amount of acid to be added stays pretty much the same with borates. You don't have to add acid as often, but higher quantities when you do add acid to get the same pH-change, because the Borates increase the overall buffering. Instead of adding let's say 1.5 gallons each weak, you might have to add 3 gallons every two weeks, or 4.5 gallons every 3 weeks. Total amount stays the same, resulting in the same net TA-adjustments over time.

 

[JamesW]

The frequency and amount of acid added should be about the same either way.

Whether someone checks the pH daily or weekly, the amount of acid needed to lower the pH back to 7.2 should be the same for a pool with borates or without borates.

For example, the pool with borates might go to 7.5 while the pool without borates might go to 7.8, but the amount of acid required to lower the pH to 7.2 will be the same.

The only reason that it would be more acid added less frequently would be if you waited for the pH to hit a specific number before adding acid.

However, there's no reason to wait until you get to a specific pH before adding acid.

You can add it when the pH get to any measurable level above 7.2.

The amount of acid that you can add depends on how much carbon dioxide has been lost since the last time that you checked the pH.

Since the pH rises more slowly with borates, the pH will be lower, which causes more carbon dioxide to be created and lost.

All else being equal, it's easier to lower the TA with borates than without them.

 

[Enumjon]

Thanks for the help. Borates are in. My pool is the perfect size, a 55# bucket puts it at a 50.