How to tell if a pond freezes solid

You often mention that certain techniques apply 'unless the pond freezes solid'.

Well, this may be a stupid question, but how do you tell the difference between a pond with four or five inches of ice, and one that's frozen down to the bottom?

If everything's dead, it must have frozen?

If the pond is deeper than the soil frost depth in your area, can you assume it will not freeze?


Doug says. Not a stupid question at all. Often you can see through the ice.

If you have an 12-18-inch deep pond (common because of municipal bylaws) and live in an area where the temperatures freeze for several weeks in a row, your pond is frozen unless you do something to stop it from freezing.

If your pond is deeper than the frost line, then I don't think you have anything to worry about.

Generally, on all my "built" ponds, if I was overwintering fish, I'd be using a pump or heater to keep some water clear. (mostly a pump)

And fish and plants die for more reasons than ice freezing. If the water lacks oxygen (too much debris rotting) or you whack the ice with a hockey stick - your fish are going to be distinctly unhappy. (only two examples)