How to Keep Pond Fish Alive in Winter

Northern Nevada is known for its unpredictable winters with temperatures dropping below the freezing point. So can fish survive during the winter in an outdoor pond?

The short answer is yes. But there are some important dos and don’ts.

Here are a couple of critical criteria that must be met:

  1. If pond fish are to live through winter in a pond, discontinue feeding the fish when the pond water dips below 55 degrees F. (Even if they beg.)  It’s also recommended that you reduce the quantity and frequency of feeding when water temperature drops below 60 F
  2. The surface of the pond should never be allowed to freeze over for more than a couple hours – a pond heater or stock tank de-icer is often necessary. If the pond freezes over toxic gasses from the ponds natural biologic processes may build to levels toxic for the fish.  A small area of open water, free of ice, will allow these gasses to dissipate.
  3. The pond ideally will be deeper than 30 inches with many hiding places for the fish to nestle into and hide, away from the view of predators.
  4. Pumps should be turned off – allowing the deepest parts of the water to be the warmest. If the pumps are left on too much mixing will occur and the bottom of the pond will be as cold as the surface. In very large ponds, this may not be necessary.
  5. Be prepared to go many weeks or even a month without seeing the fish – chances are they are fine. During warm spells you may see them swimming around – even pecking at rocks for morsels of food – don’t be tempted to feed them.
  6. In the spring, when the water temperature rises above 55 degrees again you can start to feed the sparingly, one or twice a week. As the water temperature moves above 65 degrees let the feast begin.

We hope these general do’s and don’ts help you decide whether to winter you pond fish outside next winter. And of course Signature is always available to answer additional questions specific to your pond.

– Andrew Peoples
Designer & Estimator
Signature’s Resident “Pond Guy”