Pond Boss Forums POND CONSTRUCTION Building a dam Siphon drain and water quality.

From what I understand, water is it's densest at 39°F. Colder than that and it floats upwards. Warmer than that, and it does the same thing. But, in winter, normally the warmest water in the pond is the densest if you don't have water entering the pond.

I'd go with the siphon and not overthink it.

In the wintertime, you don't want to have your bottom diffuser on the bottom of the deepest part of the pond anyways, it should be around 1/3 to 1/4 the total pond depth so it will leave the densest, warmest water at the bottom of the pond for a "warm water refuge".