Pond Boss Forums AERATION Systems questions evaporative cooling of small pond - think RAS

The thing about a fountain is that you are starting out with pond temp water, where both Ryan and Cecil are starting out with well water (ground water temp) water. The packed column will put more water in contact with the ambient air than a fountain will, as it is breaking up the water column many, many times as it falls thru the bio media in the buckets. A stream coming from a fountain is still largely a stream when it re-enters the pond.

If you are not using a bottom diffusion aeration system in your pond, then pulling the bottom anoxic water and shoving it thru the packed column will be a great benefit to the pond. How much will the water temp drop? I can't answer that, but going by the info on page 3 of the linked thread it looks like 5°F would be a good WAG.

What is your ground water temp and what is the water temp at the bottom of the pond?