Considering Borax, but can't keep TA down.

[rdhetrick]

Hi All,

Second season with the pool. Last year went well, learned a lot here and didn't have any major problems.

This year, I'm considering adding Borates to improve the swimming "experience", but have few questions:

I live in the Dallas area and the fill water TA is normally 110 to 120. Last year, I tried to get the TA down but could only get to about 90 because of having to add so much water due to evaporation. After the winter, it's back to around 120. FYI, for aeration, I've got a SWG and spillover spa. I also turned the PRV discharge towards the surface on the hose for the pressure cleaner to get a little more.

Other chemistry looks good and I maintain CSI between +0.1 and -0.2 (reduced some scaling in the pool).

1. Has anyone been successful in getting TA down to 60-80 and keeping it there with the high evaporation and elevated TA in the fill water? If so, any suggestions or tricks?

2. Is it really necessary to get the TA down before I add borates? I know it will be harder to lower TA after borates, but is it really that necessary?

3. For pH control, I understand that borates will not reduce the overall amount of acid used during a season, it just changes from adding a little bit frequently, to adding a higher amount less frequently - i.e. pH drifts up slower, but requires more acid to bring it back down. Is this correct?

Thanks in advance,
Rob

 

[JasonLion]

1) It is possible, but not easy. The best approach is to use an acid feed system to automatically add acid at a uniform rate.
2) No, it isn't really necessary.
3) Correct.

 

[rdhetrick]

Thanks Jason,

As a followup question:

If I've accepted that I will always have to add acid as a result of increasing pH due to the SWG and other aeration, and I'm able to maintain the other parameters where I want them, I don't see any real benefit in lowering the TA. I guess what I mean, is that my TA is high enough that I don't have pH swings, and I will always be facing rising pH from the SWG so why try and lower the TA? Would you agree, or am I missing something?

Thanks again!

 

[JasonLion]

Your conclusion is fairly reasonable, though I don't agree with your reasoning. Your fill water has high TA, which means you will almost always have high TA, and that means you will almost always have rising PH and almost always be adding acid to prevent the PH from getting too high. So in effect you will be constantly lowering the TA, though you can call it constantly lowering the PH if you want. But I agree, there is no point in aiming for a specific TA level. If you keep your PH in range, you will being doing everything you need to do.

If your fill water didn't have high TA, you could lower the TA enough to stop or at least dramatically slow, the PH increase.

 

[rdhetrick]

Thanks, I appreciate the response. I see your point about continually lowering the TA.