Pond Boss Forums POND CONSTRUCTION Creating habitat Heat a pond

Todd, that's what I do (actually I switch to a different diffuser and placement)

In a pond that has both deep and shallow diffusers, the deep diffuser was left open about 20% for half the winter (I wonder why there's that wet spot on the ice where the deepest diffuser is???? )

Water temps at the bottom of the pond were measured at 36.5�F before I realized why that was and turned the deepest diffuser off 100% of the way. No fish were noted as being winterkilled, but then again I don't know if the pond wauld have gotten colder if the diffuser would have stayed partially open. I wasn't going to take that risk, so I shut it off. Now mind you, this wasn't open enough to see bubbles, just open enough for the ice to let water thru it when there was snowpack on the ice.