This is new: Can't keep Ph down. Alkalinity is 90.

[Mayday]

I never had trouble with Ph before. I would add about a cup or so every week, and things were fine. But for the last few weeks, it keeps rising to 8.0 or higher in a few days for some reason. Just two days ago it was 7.6 (I put in about three cups of muriatic acid), today it's back up to 8.0.

My alkalinity right now is at 90. Calcium hardness is normal. SWG running at about 60% for 10 hours. Chlorine is steady at about 10 ppm. I keep it high because I had a problem with mustard algae last summer and I don't want it returning.

What could be forcing it up? We haven't had any heavy rain in a month.

 

[Rancho Cost-a-Lotta]

Lowering your TA will help control pH rise. Try targeting a TA of 60-70 ppm.

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.troublefreepool.com

Aeration caused by water features or spa bubblers will push pH up. Your fill water along with increased evaporation could be another source for increasing TA levels and pH rise. For many of us, rising pH and MA dumping is just a fact of life. You can just live with it and add MA as needed to keep pH in range..

 

[Mayday]

Lowering your TA will help control pH rise. Try targeting a TA of 60-70 ppm.

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.troublefreepool.com

Aeration caused by water features or spa bubblers will push pH up. Your fill water along with increased evaporation could be another source for increasing TA levels and pH rise. For many of us, rising pH and MA dumping is just a fact of life. You can just live with it and add MA as needed to keep pH in range..

Thanks- I was under the impression that the alkalinity target was 80-100. Isn't 60-70 a bit too low, because I thought those levels could result in unstable Ph. Is that wrong?

Also, the reason I posted is because this was not an issue for years. Maybe it's because I accidentally pushed the TA up too much. It used to be lower, and I added some baking soda, although I only went from like 70 to 90.

 

[Rancho Cost-a-Lotta]

Lower TA will actually help to stabilize the pH a bit more. For SWG pools, we recommend a lower TA level. This helps to reduce scaling tendencies within the cell, but also works against pH rise... check for your recommended levels here.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

 

[PoolStored]

Isn't 60-70 a bit too low, because I thought those levels could result in unstable Ph. Is that wrong?

pH can be unstable below 50. 60 gives you a bit of cushion. 60-80 is your sweet spot.

 

[jark87]

I can attest to the lower TA working. I now keep mine in the 60-70 range and while I still have to add MA once a week, it’s now only a pint at a time. Prior to lowering the TA, I was adding a quart+ per week.