Hot Tub High TA & Ph - can't lower under 240 - what else causes high TA

[Farmgal]

I purged with Ahhsome, drained and refilled my hot tub and after 1 week I still have not been able to lower TA. (FYI - I also use the floating frog)
Using TF-100: Same readings from the 2nd day after new fill to today.
Cl 0.5-1.0
TA 240
Ph over 8.2
The water is clear and clean looking with little to no foaming or staining.

Throughout the week I added Spapure pH down (1.5 lb container) - almost the entire contents and TA has not lowered.
Can high hardness be an issue? My fill water is a combo of well and water softener - we have very hard water with metals.

I used the PoolMath and it calculated the following results that should occur after adding dry acid:

Are there different types and potencies of dry acid?

(I will not be using the Spapure chemicals after I use all of the bottles that came with the hot tub in May. Thanks to you I am using baking soda to riase TA when nec.)

 

[Krulligo]

I just refilled my spa last weekend (also did Ahhsome purge) and have been lowering the TA down to what is stable for me throughout the week. This is what works for me:

For my tub and my use, I need to get down to TA 50-60ppm and add 50 ppm borates to get a stable ph of 7.6-7.7 without much drift. Any higher TA and my PH shoots up within a matter of 24hours. My refill water was at 120 TA. So what I did was I measured my pH every other day, and added enough Muriatic acid to drop my pH down to 7.0. So initially drop pH down to 7.0, wait couple days for pH to rise, then drop down to 7.0 again. Do this until you reach desired TA (in my case its 50-60 ppm. Once I got there, I added 50 ppm borates and the required Muriatic acid to combat the high pH of the borax. I add the borates both for feel of water as well as it keeps my pH stable.

Now in your case, you are using SpaPure pH down. Are you sure this is dry acid? Do you know the exact contents? Why not just use Muriatic acid? When you add it, does it affect your pH?

 

[Farmgal]

Thank you for your input. I will go buy the muriatic acid. Spapure is 100% Sodium Bisulfate. I only used it as it came with my hot tub and I wanted to use up the chemical. And the hot tub store said 3 ounces would lower TA but it didn't.

What does the borate do?

 

[Krulligo]

For me, I use borates cause it makes the feel of the water more "silky". Just a preference. Some people also say it gives the water more of a sparkle. However, it does help with pH drift as it helps to "lock in" the pH for me. So once I get my tub to the specs I want, I rarely have to adjust pH afterwards as it sits stable at 7.6-7.7.

 

[Farmgal]

Interesting about berates. Must be similar to what's in the product Spamarvel conditioner and treatment that the hot tub store wants me to buy.

 

[Mdragger88]

You do not want to lower your ph below 7.0 - that is very bad for your equipment.

Lower Total Alkalinity

A lower Total Alkalinity level can help a pool owner stabalize their pH increase. We'll explain how to lower TA with a little help from muriatic acid.

www.google.com

The spa frog mineral cartridge contains calcium carbonate which increases ph & ta & isn’t assisting in your endeavor.
I suggest ditching the frog & following this guide

How do I use Chlorine in my Spa (or pool)?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...

www.troublefreepool.com

Borates can come after you get the ta down a bit - adding them now would mean it would take even more acid to have the same effect on ph. Using mystery combination chems to add borates is not recommended. Using boric acid is the recommended method. It can be accurately dosed via PoolMath.
Spa marvel lists all of its ingredients as “proprietary” so there is no way to know what it actually contains or how it’s ingredients will effect your water’s parameters.

Borates in pool - Further Reading

www.google.com

The premise of tfp is to test your own water & only add what it needs with accurate measurements - no more, no less.

 

[Farmgal]

"The spa frog mineral cartridge contains calcium carbonate which increases ph & ta & isn’t assisting in your endeavor.
I suggest ditching the frog & following this guide "

I use the @ ease frog as I still have much of the product and it helps when we only use the tub 1x week or leave for a while.

10/22: after drain and refill of 1/2 well and 1/2 water softener water
Ph +8.2
TA 240

11/8:
Ph +8.2
TA 120

Throughout the 17 days I added 1.5 pounds Spapure down & then 5.5 ounces of 34% Muriatic Acid.
Weekly, I add 1.5 ounces of Aqua Clarity, 2 ounce of oxidizing shock (spapure - mono pot) and keep the @ease floating frog in the tub

What is going on? Is the high concentration of metals creating this problem? How can I lower the Ph without lowering the TA? And how can I alleviate this problem next time I drain and refill?

 

[Mdragger88]

Use acid to keep ph in the 7’s, TA will lower over time as you continue to do this.
Unless ta is below 50 theres no issue. The lower the ta is the less rapid the ph rise will be.
Ph rise is inevitable in a spa due to the aeration & will always need to be monitored. Getting the TA down near 50/60 can help along with adding borates after reaching that point. You have high ta fill water, there’s really no way around that.
Smaller drops in ph won’t have as much of an effect on ta (say from 8.0 to 7.8 instead of to 7.2 for example). Until Ta comes down quite a bit (near 50/60) there’s no need to worry about that.

 

[Krulligo]

Your TA is still too high at 120ppm. My fill water when I restart my hot-tub is always at 120ppm and I get pH rise from mid 7's to 8.2+ in less than 12 hours. Keep lowering your TA by dropping your pH down to 7.0 with muriatic acid, then letting it rise up again. Once the pH starts to stabilize at around 7.6-7.8 that is the optimal TA for your tub.

Also make sure to keep your air valves for your spa jets closed when not in use.

 

[Farmgal]

Sounds like I need to continue with acid and be patient. Thank you!