Pond Boss Forums POND CONSTRUCTION Building a dam Cold water siphon discussion

Yes. Water is densest (i.e. heaviest) at 39°F. So, in the winter, the deepest water in the pond will be hovering around that temp. It may be a bit higher, but not lower, and if you pond ices over, it won't be in the high 40's or low 50's. The warmer the water, the lighter it is. When it gets to the surface in cold weather, it cools down, gets denser and sinks. That happens until it freezes over. I have seen water in the low 40's in my pond when it was iced over without aeration right below the ice. It was colder than that at at the bottom of the pond - only 2 degrees, but colder.

With a bottom diffuser aeration system, typically you want the diffuser on the bottom in the deepest part of the pond for the summer, and about 1/4-1/3 the total pond depth for the winter. I'll bet that you could put a diffuser up off the bottom during the summer (maybe half the total pond depth) and keep the water down there cold for your cooling needs, but still keep the O2 levels in the upper portion of the water column higher than without an aeration system. That's a SWAG, as I don't know the layout of your pond.\

Or, an agitator with a short tube would work in the summer too.