constantly fighting high PH and low Alkalinity levels

[azpaoh]

Hi,
My spa is constantly low alkalinity and high PH.
I use Taylor 2106 Test Kit. Bromine.
It is a constant battle to add Dry Acid to lower my PH, which in turn lowers makes my alkalinity even lower, and then add ALK PLUS which in turn raises my PH.
I can NEVER seem to get both at the correct levels at the same time.
Any suggestions?

 

[mknauss]

Welcome to the forum.
Can you post a recent set of test results using your Taylor 2006 kit?

 

[azpaoh]

Using Taylor K-2106 Complete (FAS-DPD Bromine) Test Kit​

JUL 28: ALK 70 – PH 3 DROPS

ADDED 6 OZ ALK PLUS

JUL 30: ALK 90 – PH 7 DROPS

ADDED 4 OZ PH MINUS

AUG 2: ALK 70 – PH 4 DROPS

ADDED 9 OZ ALK PLUS

AUG 4 ALK 130 – PH 7 DROPS

ADDED 8 OZ PH MINUS

AUG 6: ALK 90 – PH 4 DROPS (HARDNESS 140 – BROMINE 3)

ADDED 8 OZ PH MINUS

AUG 8: ALK 30 – PH 1 DROP

ADDED 6 0Z ALK UP

AUG 10: 100 ALK – PH 5 DROPS

ADDED 10 OZ PH MINUS

Aug 12: 60 ALK – PH 1 DROP

 

[mknauss]

Can you post real test data. I do not see any pH data. What are you adding? Baking soda or soda ash? And why? The TA is never low.

 

[azpaoh]

Hi,​

Thanks for your response.​

I am using Dry Acid to lower my PH level (97% Sodium Bisulfate; 6.7% Sodium Sulfate).​

To raise Alkalinity, I am using 100% Sodium Hydrogen Carbonate.​

Why am I trying to raise TA?, because I am attempting to get ALK readings between 80 and 120 and trying to get PH between 7.2 and 7.8.​

Sorry for the “drops” description for PH levels. The Taylor K-2106 Test Kit only reads PH levels up to 8.0, which would be RED in color. Each “drop” of reagent I put in is supposed to equate to having to put ½ ounce of PH minus. My PH is usually higher than 8.0, but have no idea what reading mine is.​

I do know that it takes 3 ounces of PH minus to lower my PH one drop, but 3 ounces of PH minus also lowers my ALK by about 20-25.​

My spa is 430 gallons.​

Let me tell you this, todays readings are:​

ALK 60​

PH 8.0? Took 2 drops to get to 7.5​

Hardness 160​

Bromine 1.5​

What do you suggest I do today? I shocked it Friday and the spas was drained July 15th.​

The water looks good.​

 

[mknauss]

If you wish to try and keep a high TA you will constantly be having this issue. Let the TA fall to 50 ppm. That should reduce the pH rise.

 

[phonedave]

In a spa, your pH is going to rise because of the aeration of the jets. It will reach a equilibrium at a certain TA, where it stays pretty much stable.

The system of your water, your jets, etc is going to determine that TA / pH relationship. You are trying to drive your pH and TA to a point where it is not in balance. Get your pH where you want it, and your TA will follow to a balance point, and as mknauss says, that is usually somewhere around 50 ppm. My tub likes to stay at 60 ppm TA and 7.5 pH

 

[wayner]

For me it is really hard to get a balance as the pH shifts constantly. The best I can get is a pH of 7.5 and TA of 30-40. Then the pH tends to rise above 80, I add liquid MA and get back to where I started. If I add baking soda to get TA up it throws off the pH. I find it to be a constant tug of war in my spa. My pool is stable on both pH and TA but I can never win this battle in my spa. I have a SWCG in the spa, so that may also be causing a slightly higher pH rise.

 

[Krulligo]

In my tub I maintain TA around 40-50ppm and that allows me to get pH in the 7.5-7.7 range. I also run 50ppm borates which helps lock these values in. Once I have everything set, my pH and TA usually don't fluctuate much and I don't have to adjust for at least a couple months.

With having a TA at 80-120 in my spa, my pH would be above 8.2 in a matter of hours.

 

[wayner]

If you wish to try and keep a high TA you will constantly be having this issue. Let the TA fall to 50 ppm. That should reduce the pH rise.

Is there a recommended levels page on TFP for spas? Many folks are probably going by the recommended levels for pools.

 

[mknauss]

Levels for water chemistry are the same regardless. You can adjust based on your conditions.

There is no dedicated information for Spas. TFPC is for pools. Spas are an offshoot to the process.

 

[wayner]

Levels for water chemistry are the same regardless. You can adjust based on your conditions.

There is no dedicated information for Spas. TFPC is for pools. Spas are an offshoot to the process.

But didn't you say up above "If you wish to try and keep a high TA you will constantly be having this issue. Let the TA fall to 50 ppm. That should reduce the pH rise."

The recommended TA that I get is 60-80 which is a bit higher than seems possible with a spa.

 

[mknauss]

The TA range is 50-90.

 

[Krulligo]

I find the range completely depends on your specific spa and how you maintain and use it. How often it is used, by how many people, whether you do bromine vs chlorine sanitization, do you have borates, whether you always close up your air vents when spa is not in use or leave them open, whether your circulation pump is running 24/7 or not, how your cycles are set up, etc. In your case, you should keep adding acid to counter the pH until it stabilizes in the mid to high 7's. If you want to find your values faster, don't just drop pH from 8 to like 7.6, drop it way down to 7.2 and see what its at the next day. Chances are it will still rise quite fast, but once it becomes stabilized at like 7.6 or so, measure what your TA has dropped to and that is the optimal TA for your tub.