Recommendation? Non freezing liquid for hand sanding?

[Fixall]

I don't think an aquarium pump will stop a Canadian winter....
I'm south of him by a good ways, and it gets Deadly Cold here.
I can't even imagine it there!!!!

Not an aquarium pump... A submersible aquarium heater. You may be right though. However, I used to live in Ellensburg where the temps would drop below -10f on occasion (-23c) and a 50w aquarium heater was enough to keep a 10 gallon tank that was used to feed a flood table from from freezing in an uninsulated shop. I think those things go up to like 300w. I imagine even 75w would be more than sufficient. I wonder if there is some sort of thermal calculator somewhere....