How long to aerate

[dsm]

I am using an aerator modeled after this example: http://www.troublefreepool.com/threa...orching-hot-PA

TA is pretty high - 175. How long should I run my aeration before testing TA and pH?

Thanks

 

[epro05]

This is from "Pool School".


The acid/aeration process to lower TA:
1. Add acid to lower your PH to between 7.0 and 7.2 (this also lowers TA)
2. Aerate until PH rises to around 7.6 (the only way to raise PH without also raising TA)
3. Repeat steps 1 and 2 until you reach the desired TA.

You should post a full set of test results, to get the best advice from the forum. Use Pool Math to see how much acid to add. And keep an eye on CSI Index (using Pool Math).

 

[dsm]

Right. Thank you. I have read that. I was looking for clock time from someone who might have gone through this before me.

 

[Richard320]

In my experience, about three hours aeration is long enough to need to lower pH again. That's with 100% return to the spa, but no booster and no air jets. Your pool is larger than mine, though.

The question is why? Do you have high CH to where the CSI is dangerously high? Are you having to add acid every day to control pH? Or are you just trying to reach a suggested value?

 

[dsm]

I have to add too much acid too frequently to maintain pH. Hoping that bringing TA in line with recommendations will help balance the pool and reduce acid demand.

 

[Richard320]

I have to add too much acid too frequently to maintain pH. Hoping that bringing TA in line with recommendations will help balance the pool and reduce acid demand.

Okay, that's a good enough reason.

The acid it takes to lower the TA will end up being the same. You're just speeding up the process. The CO₂ does outgas faster at lower pH, so if you've tested and it's up to 7.5 or whatever, you don't need to wait until 7.6 to dose it again. Keep pushing it down. Just don't go below 7.0 or you might start etching the innards of the heater.