Water Balance

[LucyMarin]

Hi All,

I've read tons of posts around water balance/chemistry and even picked up the Taylor K2106. This in itself as been eye opening or, even, I dare say....Fun. At any rate, I'm obsessed over having the best water in Marin county. As for my tub, I have a 165 gallon tub with the spa frog mineral/bromine in-line system.

Refilled on the 26th and thought I had the water nailed yesterday, but this morning (like yesterday morning) the PH has drifted up near 8.0. As of yesterday evening my water was perfectly balanced at 7.6, 90, 150 for PH, TA and CH respectively. OH, and my bromine was 1. In my obsession, I tested again late last night, and saw that my PH had risen up North of 7.8. I added more PH down and this morning my PH is near 8 with a TA of 80. I just again added some more PH down and am hoping this gets me down around 7.5 or 7.6 with an expected TA of 70. Is a 70 TA acceptable? Posts on this forum indicate it is, but Taylor/ANSI and other folks are saying that the TA should be 100-120 thought a minimum of 60 seems also to maybe be alright? If my results are as anticipated, I'll bump CH up to 175 to bring the water into balance.

Any thoughts around this? I know that it's a fine balance to nail PH, but I see my TA as getting in the lower end, yet my PH continues to drift. My tub doesn't have a separate blower, but it does create a lot of bubbles when running. We're using it 1, sometimes 2 times a day for 30 minutes a pop. It's just my wife and I and we are squeaky clean when we get in. See also my refill and test history below. Is PH ever going to be my friend? Thanks in advance for your comments.

p.s. The tub is new and we do absolutely love it. Can't believe it took us so long to get one

Date Action PH TA CH

26-Feb Fill 7.6 100 150

27-Feb Test 7.9 90 140

27-Feb Add 1.25 tsp dn 2 tsp up 2 tsp up

27-Feb Retest 8 100 140

27-Feb Add 1.25 tsp dn 2 tsp up

27-Feb Retest 7.8 90 150

27-Feb Add 1.75 tsp dn

27-Feb Retest 7.6 90 150

27-Feb Retest 7.8 + 90 150

28-Feb Retest 8 80

28-Feb Add 1.5 tsp dn - -

28-Feb Retest TBD TBD TBD

[quantumchromodynamics]

Don't worry about your TA going too low. Let it go as low as necessary to stabilize the pH. I recommend a target pH of 7.5 to 7.8. Your TA will probably need to be between 50 and 70.

Once you get the pH and TA at the correct level, you can adjust the calcium to bring your CSI to between -0.3 and 0.0. I recommend a target of about -0.15 to -0.1

Adding 50 ppm of borates will help give you more pH stability.

[LucyMarin]

Don't worry about your TA going too low. Let it go as low as necessary to stabilize the pH. I recommend a target pH of 7.5 to 7.8. Your TA will probably need to be between 50 and 70.

Once you get the pH and TA at the correct level, you can adjust the calcium to bring your CSI to between -0.3 and 0.0. I recommend a target of about -0.15 to -0.1

Adding 50 ppm of borates will help give you more pH stability.

I'm struggling with the PH, but haven't given up yet. My latest readings are:

PH 7.6

TA 50

CH 170

BR 1.5

I'm holding off on raising CH to around 250, pending what my PH does overnight after our evening soak. Each of the last few days it's been 8.0 by morning. I might have to hit it hard(er) with PH down if this again happens as my tub must really be aerating the water to cause such big PH increases. I'm worried too that the TA will get too low (i.e. in the sub-40). At any rate, I'm keeping my fingers crossed.

[quantumchromodynamics]

Right now your CSI is -0.1 (Using 104 F as the temp.). That's good. You should not raise your calcium level.

You're getting close. Reduce the amount of acid that you're using. Lower the pH to 7.7 each time, not lower.

What is your water temperature?

[LucyMarin]

Right now your CSI is -0.1 (Using 104 F as the temp.). That's good. You should not raise your calcium level.

You're getting close. Reduce the amount of acid that you're using. Lower the pH to 7.7 each time, not lower.

What is your water temperature?

100 F. Using a 7.7 PH target and a 50 TA, the Taylor water balance calculator is telling me that my CH should be around 225 (at 7.6 PH, it's giving me a CH of closer to 275) for balanced water. Do you agree with this assessment? What's causing the PH to rise during the night? We just got out of the tub after a 45 minute soak and I tested PH again and it looks like it's still at 7.6, though tomorrow AM is another story. Don't get me wrong...I'm frustrated of course, but loving the tub and even finding the water chemistry to be interesting. I just want to nail it and improve with each subsequent fill

[quantumchromodynamics]

The Taylor water balance calculator does show about what you are calculating.

The poolcalculator shows slightly different numbers.

Either one is fine to use. I prefer the poolcalculator.

I think that you are doing well. Don't be too concerned about minor pH fluctuations. It's OK if the pH goes up a little overnight. It should start to stabilize soon. If it is a little high in the morning, just lower it to about 7.7.

I recommend that you keep the CSI slightly negative at about -0.1 to avoid calcium carbonate scaling.

Adding 50 ppm borates from boric acid would help stabilize the pH even more.

pH = 7.7

Total Alkalinity = 50

Calcium = 175

Cyanuric acid = 0

Borate = 50

Temperature. = 100 F

CSI = -0.1

I would recommend that you not use the spa frog mineral system. I really don't think that minerals are useful. Using just bromine or chlorine will give you the best overall results.

I also recommend reading

Nitro's Approach to Water Maintenance.

Did you add 30 ppm sodium bromide initially?

[LucyMarin]

The Taylor water balance calculator does show about what you are calculating.

The poolcalculator shows slightly different numbers.

Either one is fine to use. I prefer the poolcalculator.

I think that you are doing well. Don't be too concerned about minor pH fluctuations. It's OK if the pH goes up a little overnight. It should start to stabilize soon. If it is a little high in the morning, just lower it to about 7.7.

I recommend that you keep the CSI slightly negative at about -0.1 to avoid calcium carbonate scaling.

Adding 50 ppm borates from boric acid would help stabilize the pH even more.

pH = 7.7

Total Alkalinity = 50

Calcium = 175

Cyanuric acid = 0

Borate = 50

Temperature. = 100 F

CSI = -0.1

I would recommend that you not use the spa frog mineral system. I really don't think that minerals are useful. Using just bromine or chlorine will give you the best overall results.

I also recommend reading

Nitro's Approach to Water Maintenance.

Did you add 30 ppm sodium bromide initially?

I haven't yet added the Borate, but will pick some up this weekend. Can it be added while the tub is already filled? Didn't use sodium bromide at start-up as the dealer said I didn't need this due to the in-line spa frog system. As I understand it, I can keep the bromine lower because of the mineral, however, it sounds like you're skeptical? At any rate, I checked my numbers again this morning and I now have a PH of right around 7.7 with a TA of 40 with CH and bromine still a constant 170 and 1.5 respectively. Does a low TA ever become a problem or is it acceptable if the water is balanced? Nitro says not to let TA slip below 50 due to instability issues? Thanks.

[quantumchromodynamics]

I haven't yet added the Borate, but will pick some up this weekend. Can it be added while the tub is already filled?

The borate can be added at any time.

Didn't use sodium bromide at start-up as the dealer said I didn't need this due to the in-line spa frog system.

Sodium bromide should always be added at startup for anyone using bromine.

As I understand it, I can keep the bromine lower because of the mineral, however, it sounds like you're skeptical?

I really don't think that minerals (silver, copper and/or zinc) are a good choice. I think that the best choice for water maintenance is the dichlor/bleach method.

The main benefit of bromine is that you can use bromine tabs in a feeder, so it is more convenient for some people.

However, I think that the use of bromine tabs should be minimized because they add so much DMH (dimethylhydantoin) to the water.

DMH might reduce the effectiveness of bromine over time as it accumulates in a similar way to how cyanuric acid reduces the effectiveness of chlorine. Although, this is not certain.

People using bromine can add MPS or chlorine to regenerate bromine from the bromide in the water. Bromine from regeneration should make up the majority of the bromine and bromine from tabs should be kept to a minimum.

At any rate, I checked my numbers again this morning and I now have a PH of right around 7.7 with a TA of 40 with CH and bromine still a constant 170 and 1.5 respectively. Does a low TA ever become a problem or is it acceptable if the water is balanced? Nitro says not to let TA slip below 50 due to instability issues?

Your current CSI is -0.12. Some people do need to go down to 40 ppm for their TA. A TA of 40 ppm is fine if the pH remains stable and the CSI is above -0.30. (Ideally, around -0.15 to -0.1.).

I think that once you add the borate, you will probably be able to raise your TA to 50 ppm.

[LucyMarin]

I haven't yet added the Borate, but will pick some up this weekend. Can it be added while the tub is already filled?

The borate can be added at any time.

Didn't use sodium bromide at start-up as the dealer said I didn't need this due to the in-line spa frog system.

Sodium bromide should always be added at startup for anyone using bromine.

As I understand it, I can keep the bromine lower because of the mineral, however, it sounds like you're skeptical?

I really don't think that minerals (silver, copper and/or zinc) are a good choice. I think that the best choice for water maintenance is the dichlor/bleach method.

The main benefit of bromine is that you can use bromine tabs in a feeder, so it is more convenient for some people.

However, I think that the use of bromine tabs should be minimized because they add so much DMH (dimethylhydantoin) to the water.

DMH might reduce the effectiveness of bromine over time as it accumulates in a similar way to how cyanuric acid reduces the effectiveness of chlorine. Although, this is not certain.

People using bromine can add MPS or chlorine to regenerate bromine from the bromide in the water. Bromine from regeneration should make up the majority of the bromine and bromine from tabs should be kept to a minimum.

At any rate, I checked my numbers again this morning and I now have a PH of right around 7.7 with a TA of 40 with CH and bromine still a constant 170 and 1.5 respectively. Does a low TA ever become a problem or is it acceptable if the water is balanced? Nitro says not to let TA slip below 50 due to instability issues?

Your current CSI is -0.12. Some people do need to go down to 40 ppm for their TA. A TA of 40 ppm is fine if the pH remains stable and the CSI is above -0.30. (Ideally, around -0.15 to -0.1.).

I think that once you add the borate, you will probably be able to raise your TA to 50 ppm.

It looks like the PH is finally stabilizing. Tubbed for 45 minutes last night and checked our readings this morning:

Temp = 100

PH = 7.6

TA = 40

Ch = 170

BR = 1.5

I actually added a bit of calcium up to bring the CH to 200 and plan on trying to raise the TA to 50 once I am able to add borate (gentle spa). Will also reevaluate and finalize CH etc at that point. Quite excited to see the finish line in my balancing exercise. Thanks for the continued advice.

[quantumchromodynamics]

I think that Proteam's Gentle Spa is OK to use.

However, I prefer to use pure boric acid because Gentle spa contains "Fresh fragrance and moisturizer additives".

I don't like to add extras such as fragrance, but I haven't heard anyone complain about the Gentle Spa, so it probably won't be an issue.

You want to be careful about adding too much calcium as it could lead to calcium carbonate scaling, especially in the heater where the temperatures are much higher. Higher temperatures cause the CSI to be much higher in the heater.

Having a "Balanced" CSI is not necessary unless the tub contains plaster or grout that can be dissolved.

Most fiberglass does not need a balanced CSI. Some cheaper types of fiberglass contain calcium carbonate fillers that could require a more balanced CSI, so I try to avoid going too low, just in case.

I recommend staying between -0.15 and -0.1 for your CSI.

[LucyMarin]

I think that Proteam's Gentle Spa is OK to use.

However, I prefer to use pure boric acid because Gentle spa contains "Fresh fragrance and moisturizer additives".

I don't like to add extras such as fragrance, but I haven't heard anyone complain about the Gentle Spa, so it probably won't be an issue.

You want to be careful about adding too much calcium as it could lead to calcium carbonate scaling, especially in the heater where the temperatures are much higher. Higher temperatures cause the CSI to be much higher in the heater.

Having a "Balanced" CSI is not necessary unless the tub contains plaster or grout that can be dissolved.

Most fiberglass does not need a balanced CSI. Some cheaper types of fiberglass contain calcium carbonate fillers that could require a more balanced CSI, so I try to avoid going too low, just in case.

I recommend staying between -0.15 and -0.1 for your CSI.

Cool, thanks for the clarity. I'll re-post once everything firms up.