Need help getting TA and pH to stay at the right levels

[JLA956]

Water balances out very well using PoolMath - all of the action items are spot on as far as obtaining the proper levels I need. Here is the one area that I'm having trouble with - I'm trying to get my TA to stay at 50 but my pH measures around 7.8 to 7.9. So, when I add the recommended level of HCI per PoolMath it brings the pH right down to where I want it - 7.5. However, that also decreases the TA down to 40. So, I then add the recommended amount of baking soda to get the TA back up to 50, but then the pH goes up to 7.8 to 8.0.

How do I get the TA up to 50 without popping my pH up and out of range? I know that those two move hand-in-hand when you add HCI and/or baking soda but was wondering if there might be some particular additive that would move the TA and not the pH?

By the way, I'm using a Taylor K-2006 kit to measure with.

 

[woodyp]

You'll be fine with your ph at 7.8. No need to chase 7.5

 

[duraleigh]

I know that those two move hand-in-hand when you add HCI and/or baking soda

These rules are virtually absolute...

Lower pH - use muriatic....TA also comes down

Raise pH - use borax.....it has little effect on TA.

Lower TA - acid and aeration method....see Pool School

Raise TA - use baking soda....it has little affect on pH

You are getting some testing error if you see pH and TA moving contrary to this.

 

[ant 83]

stop testing for alkalinity. only worry about PH.

 

[Donldson]

Do not stop testing for TA, you absolutely need to monitor it. Failure to monitor TA could allow it to drop to zero, which will allow your pH to drop very low and cause damage to your tub, especially the heating element.

 

[JLA956]

Thanks Dave for pointing this out. I will use the baking soda to work on getting the TA up.

UPDATE: using Dave's product recommendations I was able to get pH down to 7.2 and TA to 20. Per PoolMath I added the recommended amount of baking soda and ran all jets for 30 minutes. TA went to 60 and pH up to 7.6 which are both good to go. Question - if I add some Gentle Spa product should it help stabilize these levels without effecting them too much? It's supposed to be pH neutral but not sure what it might do to the TA - hopefully nothing. It says it will help maintain the water balance which I'm looking to do.

Once I get that locked down then I can start tweaking my FC levels to where they need to be for using the 3-step Bromine system. I don't think my Bromide Reserves are where they yet need to be but should have that set within a few more days. I add the recommended amount of bleach every evening after we use the spa and when I check the FC in the mornings it's right at .5 to 1.0 every time. I opened the bromine tab floater up to full open and we will see how that works. I'm using a Frog Mineral Stick and it says that I only need a bromine lever of 1 - 2 ppm. If the morning check of the FC stays around .5 - 1.0 then I should be right where it needs to be since 1 FC = 2.25 bromine.

I love this forum and all of the information as to how to properly and easily (along with inexpensively) maintain a hot tub. I am so glad that I found this site prior to taking delivery of our new spa this week. I can see now that by us having maintained our old one for the past 17 years by only using the advice and products that the dealer recommended was crazy. No wonder we had so many water issues. Getting rid of strips to test the water and purchasing a Taylor K-2006 was the best thing. They gave us a bottle of test strips with our new tub and it's fun to compare the results of those strips with the results of the K-2006 testing. Once you do that then you could never really trust those test strip results. Again, thanks for everyone's help!