My backyard overhaul journal

[kien]

Originally Posted by mike31154

How do you keep the pond from freezing solid during the long Edmonton winters? I lived in the Cold Lake area for many years and the lake ice would be several feet thick! Seems to me your 24" depth could easily freeze all the way down during a cold snap? Even though the koi hibernate as Kien mentions, don't they still need O2, especially considering the size of some of those bad boys?

You need to keep the water surface agitated, for several reasons:

1. Provides oxygen
2. Helps keep a hole in the ice so that gas can escape
3. Helps keep the pond from freezing solid.

You can achieve this several ways. Either with a pump as MMAX suggested or do what Dez does and just run an air stone all winter.

[Seriak]

When I had my in ground pond (I have an above ground pond now) I would still bring my fish inside. Although I recognize the hassle, it was worth it, as if my heater / airstone / whatever stopped working for a couple of days in the middle of winter, everyone of my fish would be done for. It just wasn't worth the risk as I see technology fail all the time.