Can't win fight between pH and TA

[wayner]

I have a Jacuzzi spa that uses bromine. It isn't attached to a pool and is covered when not in use.

I can't seem to get both pH and TA to the correct level, assuming that the TA should be around 100 for my spa.

For example, I will start with a pH of 7.6 and TA of 40. I add the chemical to increase the TA. It will cause TA to go up to 80 but it will cause the pH to go up to 8.0. So I will add MA to reduce the pH which will go down to 7.4 but the TA will go down to about 30. So I will add the TA+ and cycle through this again.

Anyone have any advice?

 

[pooldv]

Set TA at 50 and add 50 ppm of borates. More here, How do I use Chlorine in my Spa (or pool)? in the TA and PH section.

 

[Brian VT]

Since he's using bromine, shouldn't he go here?
How do I use Bromine in my spa (or pool)?

 

[wayner]

Thanks - that Bromine thread is useful but I don't see any mention of the recommended TA level for a bromine spa.

So what is the recommended TA range from a bromine spa (my spa is a fiberglass Jacuzzi if that matters)? I have seen various figures including 50, 80-120 or even higher. The problem with my current low level is that the pH really moves when I try to bring it down and 2 oz of MA can move my from >8 to <7.

FYI, this is what I am currently using to increase TA: Aqua Trol Lawrason's, Inc. Pool and Spa Products - AQUA Trol 2 kg

 

[Richard320]

Thanks - that Bromine thread is useful but I don't see any mention of the recommended TA level for a bromine spa.

So what is the recommended TA range from a bromine spa (my spa is a fiberglass Jacuzzi if that matters)? I have seen various figures including 50, 80-120 or even higher. The problem with my current low level is that the pH really moves when I try to bring it down and 2 oz of MA can move my from >8 to <7.

FYI, this is what I am currently using to increase TA: Aqua Trol Lawrason's, Inc. Pool and Spa Products - AQUA Trol 2 kg

I hope that stuff isn't expensive. It's nothing but baking soda, chemically identical to the stuff you can buy at the grocery store. This is the link to the MSDS but it will download on you not just open. http://www.lawrasons.com/ps/index.php/en/msds/msds-pool/aqua-2015/aqua-trol/download

 

[pooldv]

The Bromine thread does not cover PH and TA as thoroughly as the chlorine thread. Use the info regarding PH and TA from the chlorine thread. Set TA at 50 and borates at 50.

 

[bwilford]

Hi, when I started to manage my SPA (Jacuzzi J-375) for myself earlier this year I had similar issues. I do use Chlorine, so it's not exactly the same as your situation.

At first my PH was 7.5 and the TA about 100. But I found that the PH would drift up too high (over 8.0). I never focused on the TA, just the PH. So for my situation, I added dry acid to lower the PH. That worked well, the PH came down and the TA came down, but then the PH would drift up again. As I was doing this for the first time, I added acid over a few days, maybe up to a couple of weeks.

What I found was that once I got the TA down to about 60, the PH just stabilized at a pretty constant 7.6 and those numbers have pretty much stayed there for the last couple of months. I did add 45 ppm of borates. A TA of 60 is in the range 50-80 that pool calculator suggests is reasonable for a SPA.

In order to better balance the water, I then added some calcium chloride to increase the CH, to get the SI closer to zero.

Anyway, that's how I won the fight for my SPA between PH & TA

Bruce

 

[pooldv]