CO² pH control, why bubble up your pool?
When CO² is added to water it creates carbonic acid which we can utilize to lower pH in our pools. The residual side-effect is that it will promote Total Alkalinity (TA) rise. CO² alone will require the additional maintenance procedure of column poring acid directly into the pool. This is undesirable for a few reasons we won’t discuss at this time.
The combined use of CO² and acid has both chemicals feeding at the same time when you need to lower pH. With this method, both lower pH and they counteract the TA side effects created by the other. You use less sodium bicarbonate for TA adjustment and less acid as well. Win win.