I must be going through something all new ponders do. When we first put
the pond in, my attitude about the two goldfish was, "What the heck. If
they die, $4 will get us two more." Now, as we're looking at our first
night with temps in the teens (!), I'm thinking, "My poor darlings! I
must protect them!" :-)

I've seen several references to using aquarium airstones and heaters.

When you use an airstone, you need an air pump too, right? Where do you
locate the air pump so it is protected from the elements?

With an aquarium heater, is the goal just to keep the water temp above
freezing? I've got a 90-gal. pond. Should I look for a heater for a
90-gal. aquarium?

I have a birdbath heater that I was planning to use. It consists
basically of a heating element between two thin, flexible sheets of
aluminum. It did a great job last year on the shallow birdbath, but I'm
not sure it would be effective in a large volume container.

Please forgive these really stupid questions -- but the lives of my
darlings are at stake! Thanks!

Frances (Zone 5, Wooster, OH)