There are several things a good pond keeper needs to do to winterize their Koi and Goldfish. This is an important time of year because what you do (or do not do now) sets the stage for your springtime season in March, April and May which traditionally marks the "disease season". The features to be considered are the cleanliness of the pond and filter, disease prevention (an ounce of prevention is worth more than a pound of cure), water quality, and stress reduction (For the fish! Do not handle or move). Here's a quick list of what you will need:

• Thermometer
• Water quality test kits for the testing of pH, nitrites, ammonia, alkalinity Salt test kit
• Non-iodized table salt or sea salt (optional)
• Antibiotic feed (optional)
• Low protein food
• Styrofoam, heater or air pump and air stone to prevent icing over of pond
• Pond leaf netting
• Microbe-Lift or Autumn Preparation
• Water De-chlorinator

Here are the things that you want to accomplish:

Fish should go into fall in the following manner:

• No leaf litter or mulm in filter or pond
• Salt to 0.3% (remove plants)
• Antibiotic feed (optional for 2 weeks only)
• Low protein food
• Small heater, Styrofoam or air pump and air stone
• Continue to check water quality

Fish should emerge in late winter or early spring to ponds that feature:

• No leaf litter or mulm in filter or pond Salt to 0.3%
• Resume feeding low protein food when temperature is above 43ºF

When getting ready for winter, you should consider the following for a healthy pond:

• Cleanliness of the pond and filter
• Maintain a clean pond and filter; remove all of the leaves and decaying matter on the bottom. The best time to clean your pond is just before frosty weather begins. Too much debris in the pond filter will harbor disease and cause water quality problems. If it is not possible to clean your pond in the autumn, it must be done sometime before your fish resume feeding in the spring.
• If you are using a biological filter it is wise to thoroughly clean the media prior to winter and continue running the filter throughout winter.
• Remove any ultra-violet clarifier prior to freezing conditions and place in a dry location. Re-install the clarifier in the spring once the threat of frost has passed.
• Be sure to thoroughly clean the quartz sleeve and replace the old bulb in the spring.

Steps to Salt your Pond:

Late Fall:

• Remove submerged plants;
• Clean the pond reasonably well;
• Apply non-iodized table salt dosing at one pound per hundred gallons of water every 24 hours for three treatments (3-6 pounds per hundred gallons in total is ideal).

Early Spring:

• Perform a 40 - 50% water change when temperatures reach 55ºF to reduce salt.
• Re-introduce pond plants when salt concentration is below .05%,
• Be certain you de-chlorinate tap water after each water change by adding a de-chlorinator.

Antibiotic Feeds:

Bacterial infections must be considered during the winter months. Starting and ending the season with antibiotic feeds has the benefit of ensuring that the fish neither sleep, nor emerge from sleep, with bacterial infections. An excellent diet to end the year with, and begin the next year with, would be medicated feeds containing: Ormetoprim Sulfa; Oxytetracycline: Oxolinic Acid. Such feeds should be given for no more than two to three weeks in the fall and spring.

Feeding your fish varies at different times of the year and depends on the temperature. Above 70° - feed small amounts of food 2 to 5 times daily. 60° - 70° - feed once daily. 50° - 60° - feed 3 times per week. 43° - 50° - feed when the fish are actively looking for food. 43° and under - NO FOOD AT ALL as the fish will semi-hibernate. Begin feeding the fish again when they are actively looking for food. Type of Food - High protein above 60°; Low protein below 60°.

Water Quality:

Another aspect of winter care for koi is maintaining good water quality. Water quality at this time of year is usually very good. Oxygen levels are high as cold water carries much more oxygen than warmer water does and fish metabolism is slow. Ammonia can still be a problem if you stop running your filter. Your filter is biologically less effective when water temps are below 60ºF. pH is never a sure bet, therefore periodic checking of the pH and alkalinity will avoid a "crash" which can kill fish.

ICE - What to Do - What not To Do:

The formation of ice on your pond will trap gases and other toxins underneath the ice to the detriment of your fish. This area of the country doesn't have the freezing temperatures more northern areas experience, but it is still important to keep ponds free of ice. Ice formation can destroy whole collections of fish. Do not break the ice with a concussive blow as the blow is transmitted through the water and can result in shock to the nervous system of your fish. A small floating heater or air pump with air stone will prevent total ice cover.

Stress Reduction:

Finally, it is important to keep fish as stress free as possible. About ninety-five percent of diseases a fish contracts attack the fish during times of stress. In low temperatures the immune system is slowed down and any additional stress lowers the immune system even more. Avoid handling your fish during these cold months and give them places to hide. You can use a pot, with holes in it large enough for the fish to go in, placed on the bottom of the pond where temperatures remain above freezing. Floating styrofoam on the surface not only keeps the surface water from freezing but also provides hiding places as well. Try not to stir the water any more than necessary.