Been over a year since we conversed and I have a question for you.
Last year we wintered our koi outside and covered the pond with a greenhouse type frame. Water never froze but the pond was only 24" deep and we knew the koi would not stand a chance of surviving a Michigan winter.
We built a new pond which is almost 4' deep and decided to leave them go through the winter in their own pond. We did not cover it but put a bubble, an air stone and a pond de-icer in the pond. The pond has not frozen over until last week. We have been anywhere from several degrees below zero at night to 20 above during the day for about 8 days now. The pond is frozen over and there is a hole in the ice around the de-icer, the air stone is working as is the bubbler. I have seen all of my koi alive and appearing well as if 8 days ago.
My question, now that the pond has frozen over and the temperatures have remained so cold for a prolonged period, will my fish survive and what do I need to do if they do survive, the temperatures start to warm up and now even though they survived are going to stress and possibly get sick on me.
Your help would be appreciated and thanks again, Bob.
Congratulations on the new pond.
As long as your bubbler is able to keep an opening in the
ice clear,your fish should be fine. The ice will act as
a windbreak, and as long as nothing occurs to disrupt these
conditions or excite the fish, you should have no major
problems come spring. If that hole freezes over, remember
to reopen it with hot water. Do not bang on the ice to break
it. The shock waves from the hammering will damage your
fish's sensory apparatus.
I'm a firm proponent of greenhouse covers
for ponds in our area. Even without heated water, the fish
just seem to do better under a plastic dome, and the water