What does a pool aerator do?

Pools are aerated to prevent stagnation..... no this guy doesn't know what he is talking about. .. pools are aerated to help control the PH lvl easyier. Aeration adds oxygen to the water which eliminates the carbonates in the water which messes with the PH and unbalances the water. Aeration eliminates carbonates and controls the PH without as much of the chemicals needed. Cheap way to control pH lvl