We are having issues with our pH continually running high in our pool. As a result we are running through 2 CO2 tanks in a week. We have not had any bather load in the pool yet because we are in the final stages of construction for our recreation center. All other chemicals are within normal NSPF recommendations. It is an indoor facility and the fill water has a high pH but our spa is not experiencing issues with maintaining the pH. It is a Myrtha Pool and so we do not have any leaching issues that you get with plaster pools. Has anyone else experienced a problem like this?
Check the CO2 injectors. When CO2 is introduced into flowing water it must be diffused properly in order to form into efficient amounts of carbonic acid.
If the injectors are not doing their job you will typically see what you are describing along with fizzing in the pool right over the jets. Just like carbonated soda.
Alkalinity may also be an issue. If it gets about 140 I see that our CO2 usage goes up considerably. If the injectors are not working properly the alkalinity of the water will climb quickly.
We also use CO2 and have seen problems.
One problem we've faced is leaks in the line. Our supplier set the pressure too high and it blew the line a couple of times - in a couple of different places. Some leaks were huge & easy to find. Another took some investigating. Check to see if your tanks are frosting over.
We are looking to get rid of our CO2 system.
Good luck to you.