Ozone & pH

cvicente · Mar 24, 2016

I've been experiencing a steady rise in pH since I added an ozone generator to my system, to the point that my pH now ranges from 8.25 - 8.5 from the 8.05 - 8.25 I was measuring. The meter is calibrated with Hach 7 - 10 references. I've always used a calcium reactor to keep my alkalinity in the 11-12 dKH range due to my high nutrient levels. Although I don't use a dryer and some nitric acid could be forming it doesn't seem to have a noticeable impact on pH. Besides carbonic and nitric acid, what other acids or organics known to affect pH are being oxidized by ozone and could be causing this rise on pH? Excluding the ozone generator the setup has been the same for the past 6 months.

Randy Holmes-Farley · Mar 24, 2016

I'm not sure why you are seeing the effect you are. I didn't notice a pH rise when initiating ozone, and I cannot think of any reactions that would do so.

Where is the probe in relation to the ozone addition?

cvicente · Mar 24, 2016

The pH probe is located in the first chamber of the sump, the ozone is injected in one of the two pumps of the skimmer. The skimmer is located in the middle area of the sump. The probe and the skimmer have been in the same place since last year. The rise in pH has been steady for the past couple of months.

Randy Holmes-Farley · Mar 24, 2016

cvicente said:
The pH probe is located in the first chamber of the sump, the ozone is injected in one of the two pumps of the skimmer. The skimmer is located in the middle area of the sump. The probe and the skimmer have been in the same place since last year. The rise in pH has been steady for the past couple of months.

Have you recently recalibrated it?