Might check the archives
There has been numerous posts on this. Personally, for salt water to freeze inside a ballast tank that’s surrounded on most sides by water, it would have to get cold enough to freeze the you-know-what’s off a brass monkey (where did that phrase ever come from?). But, if you live in some place like Nova Scotia – it could be a concern. Since the boat is in the water and assuming at dock – you could run a heater to keep the boat at say 40 degrees. Then, the only way for it to freeze would be for the surrounding water outside to freeze solid.
