A surface aerator basically beats oxygen into the water. It is ideal for fish farms where the carrying capacity is at its max and the ponds are typically really shallow (less than 4'). They are also ideal for emergency aeration. As far as oxygen transfer, a surface aerator can't be beat ~ don't get it confused with a fountain, though ~ fountains have a pretty display, a surface aerator churns up the surface water. A surface aerator won't de-stratify a pond and get oxygen to the bottom, but it will create a safe haven for fish in stressful times.
