Containing ph ceiling with total alkalinity

[Nfrisa]

I’ve been reading a lot about containing ph by lowering total alkalinity which should lower the ph ceiling (an upper limit on how high ph can rise). So that I don’t have to add acid as often.

You can read more about it here if you are unfamiliar. Containing pH vs. Controlling pH in a Pool

My question for the board is… I recently discovered my fill water has an alkalinity of 140. If I wanted to maintain an alkalinity of 60-70 is this basically impossible due to the fill water? Are there any other solutions to keep alkalinity low with this type of fill water?

Or am I stuck adding large amounts of acid because the high alkalinity fill water will constantly drive total alkalinity up which will always make large amounts of acid necessary?

 

[Parac]

140 isn't particularly high. My fill water is 190 and I don't have any trouble keeping it at 60-70. After you get it down the 1st time, you aren't usually adding a huge amount of fill water at any give time so TA isn't going up a lot. With my TA at 60, when ph gets over 8, I bring it down to 7.7-7.8. If my TA gets to 70 or 80, I bring ph down to 7.4-7.5 until TA comes back down.

 

[casiokid]

You’ll always have to add MA to the water as the pH will naturally rise. For some, it’s every day. For others, it’s once a month. It depends on a lot of different environmental factors.

Your TA will go down as you add MA and the pH will be somewhat stable when the TA is at 50. But you’ll still need to manage the pH.

For high TA fill water, you may look at running it through a water softener. There are also Stenner pumps and other integrated systems like the Intelliph that can automatically add small amounts of acid every hour.

You also shouldn’t be adding”large” amounts of acid to the water. A small amount per day is usually enough for people with consistently rising pH.

 

[Nfrisa]

140 isn't particularly high. My fill water is 190 and I don't have any trouble keeping it at 60-70. After you get it down the 1st time, you aren't usually adding a huge amount of fill water at any give time so TA isn't going up a lot. With my TA at 60, when ph gets over 8, I bring it down to 7.7-7.8. If my TA gets to 70 or 80, I bring ph down to 7.4-7.5 until TA comes back down.

Ok that makes sense.

So you don’t think there are any issues with having TA at 60? Most of what I have read said it should be 80-100. But if i can keep it at 60-70 my pH should not get higher than 8.

 

[casiokid]

Every pool is different. My TA is at 50 and my pH still wants to rise. But, it’s where my water is happy, so I adjust for that.

As long as your pH and TA are contributing to a healthy CSI, you’re good!

 

[Parac]

Ok that makes sense.

So you don’t think there are any issues with having TA at 60? Most of what I have read said it should be 80-100. But if i can keep it at 60-70 my pH should not get higher than 8.

TA is ok down to 50. 80-100 or 120 is the legacy / pool store advice and is better for people that typically use pucks to chlorinate. The pucks are acidic and continuously lower ph so a higher TA offsets that. With a SWG, you don't have the continuous acid additions and a lower TA is fine.

 

[Nfrisa]

TA is ok down to 50. 80-100 or 120 is the legacy / pool store advice and is better for people that typically use pucks to chlorinate. The pucks are acidic and continuously lower ph so a higher TA offsets that. With a SWG, you don't have the continuous acid additions and a lower TA is fine.

Thanks

I hate to start another thread so I’ll ask here first. Does anyone know of a ph sensor that works with Hayward OmniLogic PL?

I don’t want to spend all the money for a sense and dispense since all I would want is the sensor for the ph.

 

[proavia]

For high TA fill water, you may look at running it through a water softener.

A water softener will remove calcium from the water flowing thru it. It will not have an effect on the alkalinity.

 

[casiokid]

A water softener will remove calcium from the water flowing thru it. It will not have an effect on the alkalinity.

Good call…I assumed it would effect the overall quality of the water, but didn’t think about it not directly affecting the TA.

 

[casiokid]

Thanks

I hate to start another thread so I’ll ask here first. Does anyone know of a ph sensor that works with Hayward OmniLogic PL?

I don’t want to spend all the money for a sense and dispense since all I would want is the sensor for the ph.

For the most part, we all test our water at LEAST weekly if not daily, so our pH sensors are one of the recommended test kits.

Most digital pH sensors use some form of electrical conductivity which isn’t a recommended or accurate method for testing.

Do you have one of the recommended test kits?

 

[Nfrisa]

For the most part, we all test our water at LEAST weekly if not daily, so our pH sensors are one of the recommended test kits.

Most digital pH sensors use some form of electrical conductivity which isn’t a recommended or accurate method for testing.

Do you have one of the recommended test kits?

I do I have Taylor 2006 but it doesn’t seem that accurate and it’s hard to know what the ph is above 8. More than that I wanted to be able to monitor the ph remotely and know when to add more.

 

[Blackdirt Cowboy]

Yeah I wouldn’t consider your fill water high in TA, mine is 340. What does seem to be a blessing in disguise is I think my fill water will be perfect for our new pool plaster. I read somewhere that you want CH and TA added together to be at least 400. Mine will be 590. On the other hand, I feel like I’m going to have a real battle on my hands managing the pH. Weird thing is, even with a TA of 340, the pH of my fill water is 7.2

 

[SoDel]

I do I have Taylor 2006 but it doesn’t seem that accurate and it’s hard to know what the ph is above 8. More than that I wanted to be able to monitor the ph remotely and know when to add more.

There’s at least two ways of going at what you’re after. One way, the TFP way, is likely the easiest and says simply when your pH hits 8, lower it with acid and as your TA comes down as a result, pH rise will slow to a reasonable level and acid additions needed less frequently. Another way, seems like more work and not as tried and true, is to manage pH above 8 and use an accurate pH meter, frequently and properly calibrated, to keep tabs on pH. With either method, balance the rest of the water chemistry to keep CSI within the recommended range over whatever pH range you are containing pH within. I don’t know as a matter of fact but my sense is that a once and done calibrated pool probe thing is more of a pH guess than an accurate measurement.

This pH meter works well: https://www.amazon.com/Apera-Instru...8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

If you go that route, make sure you also get the 3 calibration solutions and the storage solution.

I’ve used both methods and let’s just say the TFP method is less of a headache. If you like or at least don’t mind calibrating the pH meter all the time, you might decide to go that way.

 

[reggiehammond]

What does seem to be a blessing in disguise is I think my fill water will be perfect for our new pool plaster. I read somewhere that you want CH and TA added together to be at least 400.

Please read up on start-up of new plaster.

Start-up New Plaster

The first few months are the most criticle for a newly plastered pool. We're here to share best practices to ensure the plaster will last for many years.

www.troublefreepool.com

I think you'll find quickly that high TA fill water is a bit of a curse. It's manageable, but given our continuing hot and dry summers in Texas, you'll become quite adept at acquiring large amounts of muriatic acid. TA contributes highly to CSI which in turn must be managed to preserve your SWCG from scale. Fall asleep for even just a couple of weeks and you'll wake up with a SWCG full of scale and shut down.

 

[cwswifty]

There’s at least two ways of going at what you’re after. One way, the TFP way, is likely the easiest and says simply when your pH hits 8, lower it with acid and as your TA comes down as a result, pH rise will slow to a reasonable level and acid additions needed less frequently. Another way, seems like more work and not as tried and true, is to manage pH above 8 and use an accurate pH meter, frequently and properly calibrated, to keep tabs on pH. With either method, balance the rest of the water chemistry to keep CSI within the recommended range over whatever pH range you are containing pH within. I don’t know as a matter of fact but my sense is that a once and done calibrated pool probe thing is more of a pH guess than an accurate measurement.

This pH meter works well: https://www.amazon.com/Apera-Instruments-AI311-Replaceable-2-00-16-00/dp/B01ENFOIQE/ref=sr_1_1_sspa?dib=eyJ2IjoiMSJ9.4hCq6s7C6u0lMvg0lda4YvYE_KI4TFLG_ZjaZWyrUoJMvw8SFT7-axiVVUct1ui7jEjJhD_p6EXrS0vLA5-6H9Jna-_dQ7KpjbI5kBqz0_Nr4uHtPWXSsMn7dawgru0Q-E0KIKNb232qaoIHLAw0jHjORKCcfD7H6cGzENxuwZscAt_WbiBDsaloJ2Iq_yx7lFBMael74AGVVNqvsN3O2cGXsakR7Dd-TIjBIb5Om94.ycK9fZ50QwyPYtK_ZyPeWvOB60AWoYBZlvbCo_srppQ&dib_tag=se&hvadid=580942373491&hvdev=c&hvlocphy=9007519&hvnetw=g&hvqmt=e&hvrand=11922310328625090897&hvtargid=kwd-276641792301&hydadcr=20222_13329118&keywords=apera+ph+meter&qid=1724855066&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

If you go that route, make sure you also get the 3 calibration solutions and the storage solution.

I’ve used both methods and let’s just say the TFP method is less of a headache. If you like or at least don’t mind calibrating the pH meter all the time, you might decide to go that way.

I'll add some information about the Apera PH60 linked here from my personal experience. I bought one back in early May of this year. It comes with 3 buffer solutions (4.00, 7.00 and 10.01) and a tiny bit of storage solution. I purchased more of the storage solution (Amazon) and an additional buffer solution with a pH of 8.2 (Hanna). That way I can check the accuracy in the specific range I'm most interested in. It has almost been 4 months since the purchase and I have not calibrated the unit a single time. I checked the calibration 3 days ago with the 8.20 buffer solution and the meter indicated 8.24 (off by 0.04). Not too shabby IMO.

 

[SoDel]

I'll add some information about the Apera PH60 linked here from my personal experience. I bought one back in early May of this year. It comes with 3 buffer solutions (4.00, 7.00 and 10.01) and a tiny bit of storage solution. I purchased more of the storage solution (Amazon) and an additional buffer solution with a pH of 8.2 (Hanna). That way I can check the accuracy in the specific range I'm most interested in. It has almost been 4 months since the purchase and I have not calibrated the unit a single time. I checked the calibration 3 days ago with the 8.20 buffer solution and the meter indicated 8.24 (off by 0.04). Not too shabby IMO.

It is a quality meter. The issue I run into is the only way to tell if it’s calibrated is to calibrate it (or at least do a “sanity check” as you mention). The previous calibration will remain valid until it isn’t and there’s no way to tell other than check it. So for me at least, the question I ask myself is do I want to add acid once in a while at 8, or do I want to check my meter each time I test and let the pool float to a bit above 8 where it tends to stay, but not always. For me, the former has become more appealing. Just a personal choice.

 

[Newdude]

The previous calibration will remain valid until it isn’t and there’s no way to tell other than check it.

Sounds pool-store-free-test-y to me.

But at least you can prove/disprove it fairly easily.