Question
QUESTION: I have recently installed 190 gallon pond.  It's about 20" deep.  I have a few hardy goldfish in it, and a waterfall. I live in zone 7.  I was wondering what if I could keep the fish in the pond during the winter, or if I should put them indoors.  If I keep them outdoors, would I need to get a de-de-icer and an aerater?

ANSWER: Hi Sally,
Thanx for your question.  I would keep my fish outdoors if I were you.  If your ponds freeze over you'll need to make sure there is a hole in the ice so the water can exchange gases with the atmosphere otherwise the fish will suffocate from lack of oxygen and die. Check this URL for ideas and then pay a visit to your local pet store or DIY store that specializes in water gardens.   http://www.pet-dog-cat-supply-store.com/shop/ponddeicers.php  Believe it or not, the contraption is not expensive to run.  I hope this helps.
Tom

---------- FOLLOW-UP ----------

QUESTION: Would a floating de-icer keep enough of the bottom un-frozen, or should I buy a submersible de-icer?  Also, do fish need any aeration during the winter?

Answer
Hi Sally,
Thanx for the additional information.  I live in the Kansas City area and have used the floating deicer.  All it does is keep a hole clear where ice can't form and the water is about 38 degrees so it is still cold but can't freeze.  Ice freezes from the top down and your zone your pond is 20 inches deep, I doubt if you will get ice that far down.  I am in a cooler winter than you and have never had it freeze down farther than an inch or two, so the submersible deicer is unnecessary.  Aeration is optimal and I would advise if you already have an aerator and filter, keep them running through the winter.  I hope this helps.
Tom