If you must move fish inside for the winter, do this gradually. Move a few fish inside to an aquarium or stock tank that has been set up in advance using pond water.

Make sure that their winter home is large enough to accommodate them without over crowding them. Figure 1" of fish length for every square foot of water surface. If you have a lot of extra filtration or lots of surface coverage with plants, you can bump that to 2 or 3 " of fish for each square foot of water surface.

Bring in as many plants as practical so that you have good water surface coverage. A tank, pond or aquarium that has a nice amount on surface plants will make for happier fish. Rarely, if ever does a fish "jump" if you have good plant coverage. When they get scared they will hide under the plants.

If there are no plants and the fish gets scared, he will jump out. I have never had a fish "jump out" in ponds or tanks that have good water surface coverage of plants!! But over the years I have lost my share of jumpers to tanks that do not have plants. I now keep netting over my non-plant tanks.

Place lights above tank to support plants. Use a timer on the lights so that they have 10-12 hours of light a day.

If practical, move your pump and filter too so that fish will be in almost identical situation as they were in outside. Do not move all fish inside in a new tank all at one time or they may all die. Plan to do this task early enough in the fall so that you can add a few fish every week.

Monitor ammonia, pH, nitrite, and nitrate very carefully and take corrective measures if these measurements go out of balance.

Feed very sparingly daily so that you do not get an ammonia spike. After a few weeks, increase feedings.