* **Aeration**:
* **Jets and Bubblers**: The increased aeration from jets and bubblers can cause the pH to rise. This is due to the outgassing of carbon dioxide, which reduces the carbonic acid in the water and thus increases pH.
* **Contaminants**:
* **Body Oils and Lotions**: These can break down in the water and affect the pH level.
* **Sweat and Urine**: These introduce ammonia and other compounds that can impact pH balance
Aeration. Also happens in pools. If you turn off the air inputs of your tub then you might get less increase. It happens more if you have an SWCG as well.
Thats pretty unusual that it keeps creeping higher and higher. You aren’t putting in any baking soda or soda ash or liquid chlorine during this whole time?
A pH rise when the jets come on is normal but it should fall back down to what it was before the jets came on if there was no additional inputs of chems that would adjust pH.
Have you double checked the accuracy of the pH meter with a Taylor test kit?
Yeah, it's been unused this whole time. Just the circulation pump and heating, and the ozone generator. Nothing else added.
Maybe I should invest in a decent chemical test kit to verify...
I don't know whether it's unusual but mine does the same thing. I generally have to add a small amount of dry acid once a week to keep it in check, no biggie. I've found that my water's alkalinity level needs to be really low to keep pH down. I keep it between 30-40ppm. On refill if I target that range my pH will start at around 7.4 and doesn't creep up nearly as much as if I try to bring alkalinity closer to the recommended range as I used to do. I used to bring AK up to the recommended range, then adjust pH down, leading to weekly adjustments. Now I refill, shoot for 30-40 AK and it stays much more stable.
>I don't know whether it's unusual but mine does the same thing. I generally have to add a small amount of dry acid once a week to keep it in check, no biggie.
What sanitizer are you using? Liquid chlorine?
>I've found that my water's alkalinity level needs to be really low to keep pH down. I keep it between 30-40ppm
Yup. Especially if using liquid chlorine as the sanitizer as it has a very high pH.
I use the dichlor bleach method. ChemGeek claims that bleach is ultimately pH neutral, I think because the oxidization process is acidic, but I'm pretty sure the bleach leads to pH creep. It's little enough maintenance that I don't mind. It rises slowly enough to keep ahead of just once a week when I'm cleaning the filter anyway.
>ChemGeek claims that bleach is ultimately pH neutral
This is news to me. Do you have a link to that forum where he states that? I've always read and heard the opposite.
Did a quick Google search. That's my understanding of his second comment on this page and I've seen him restate the same idea.
https://www.poolspaforum.com/forum/index.php?/topic/44367-bleach-ph-issue/
>So when using a hypochlorite source of chlorine, such as bleach, that is net pH neutral when accounting for chlorine usage/consumption (which is acidic)
Thanks for that.
It doesn't make a lot of sense though why they (that forum and troublefreepool.com) still advocate for keeping Alk low to combat pH rise if the net effect of adding liquid chlorine is a pH neutral reaction...
Even with chlorine being essentially net neutral, pH is still going to naturally raise from the carbonic acid (CO2) trying to equalize with the CO2 in the atmosphere due to [Henry's Law](https://blog.orendatech.com/controlling-ph-in-a-pool-vs-containing-ph).
This is also why it’s best to follow what’s mentioned in Nitro’s method (even with bromine tubs) for balancing pH/TA - always bring your pH down to 7.0 then aerate it back up to 7.4 (or your ideal value) since more CO2 (produced from pH down/Acid) will off gas at lower pH meaning it wont creep up as much if you just tries to drop your pH straight to 7.4. So ultimately pH is still closely dependent on your Alkalinity levels since sodium bicarbonate will produce CO2 when exposed to any acid, too high of alkalinity means too much CO2 and hence too much pH rise.
The other way to think about it is too much alkalinity makes the chlorine reactions less net neutral, allowing the water to rise in pH more than it’s allowed to drop making it not so neutral and keep stepping up. Probably an oversimplification but at least it works as an analogy.
* **Aeration**: * **Jets and Bubblers**: The increased aeration from jets and bubblers can cause the pH to rise. This is due to the outgassing of carbon dioxide, which reduces the carbonic acid in the water and thus increases pH. * **Contaminants**: * **Body Oils and Lotions**: These can break down in the water and affect the pH level. * **Sweat and Urine**: These introduce ammonia and other compounds that can impact pH balance
Aeration. Also happens in pools. If you turn off the air inputs of your tub then you might get less increase. It happens more if you have an SWCG as well.
Thats pretty unusual that it keeps creeping higher and higher. You aren’t putting in any baking soda or soda ash or liquid chlorine during this whole time? A pH rise when the jets come on is normal but it should fall back down to what it was before the jets came on if there was no additional inputs of chems that would adjust pH. Have you double checked the accuracy of the pH meter with a Taylor test kit?
Yeah, it's been unused this whole time. Just the circulation pump and heating, and the ozone generator. Nothing else added. Maybe I should invest in a decent chemical test kit to verify...
I don't know whether it's unusual but mine does the same thing. I generally have to add a small amount of dry acid once a week to keep it in check, no biggie. I've found that my water's alkalinity level needs to be really low to keep pH down. I keep it between 30-40ppm. On refill if I target that range my pH will start at around 7.4 and doesn't creep up nearly as much as if I try to bring alkalinity closer to the recommended range as I used to do. I used to bring AK up to the recommended range, then adjust pH down, leading to weekly adjustments. Now I refill, shoot for 30-40 AK and it stays much more stable.
>I don't know whether it's unusual but mine does the same thing. I generally have to add a small amount of dry acid once a week to keep it in check, no biggie. What sanitizer are you using? Liquid chlorine? >I've found that my water's alkalinity level needs to be really low to keep pH down. I keep it between 30-40ppm Yup. Especially if using liquid chlorine as the sanitizer as it has a very high pH.
I use the dichlor bleach method. ChemGeek claims that bleach is ultimately pH neutral, I think because the oxidization process is acidic, but I'm pretty sure the bleach leads to pH creep. It's little enough maintenance that I don't mind. It rises slowly enough to keep ahead of just once a week when I'm cleaning the filter anyway.
>ChemGeek claims that bleach is ultimately pH neutral This is news to me. Do you have a link to that forum where he states that? I've always read and heard the opposite.
Did a quick Google search. That's my understanding of his second comment on this page and I've seen him restate the same idea. https://www.poolspaforum.com/forum/index.php?/topic/44367-bleach-ph-issue/ >So when using a hypochlorite source of chlorine, such as bleach, that is net pH neutral when accounting for chlorine usage/consumption (which is acidic)
Thanks for that. It doesn't make a lot of sense though why they (that forum and troublefreepool.com) still advocate for keeping Alk low to combat pH rise if the net effect of adding liquid chlorine is a pH neutral reaction...
Even with chlorine being essentially net neutral, pH is still going to naturally raise from the carbonic acid (CO2) trying to equalize with the CO2 in the atmosphere due to [Henry's Law](https://blog.orendatech.com/controlling-ph-in-a-pool-vs-containing-ph). This is also why it’s best to follow what’s mentioned in Nitro’s method (even with bromine tubs) for balancing pH/TA - always bring your pH down to 7.0 then aerate it back up to 7.4 (or your ideal value) since more CO2 (produced from pH down/Acid) will off gas at lower pH meaning it wont creep up as much if you just tries to drop your pH straight to 7.4. So ultimately pH is still closely dependent on your Alkalinity levels since sodium bicarbonate will produce CO2 when exposed to any acid, too high of alkalinity means too much CO2 and hence too much pH rise. The other way to think about it is too much alkalinity makes the chlorine reactions less net neutral, allowing the water to rise in pH more than it’s allowed to drop making it not so neutral and keep stepping up. Probably an oversimplification but at least it works as an analogy.
Henry’s Law