1. Adjust Fish Feeding

As temperatures drop, so does your fish’s metabolism. Once the water temperature reaches 10°C or below, begin to slow feeding and eventually stop altogether. Fish struggle to digest food in colder conditions, which can cause uneaten food to rot in their systems or sink to the bottom, contributing to sludge and nutrient buildup. If specialized cold-weather fish food is unavailable, 10°C is a good threshold to cease feeding.

Key signs your fish are ready for reduced feeding include a lack of interest in food or uneaten pellets remaining in the water. Gradually lower feeding frequency and stop entirely when temperatures consistently reach 4-5°C.

2. Install a Pond Net

A pond net is a simple but effective solution for protecting your pond during winter. It serves two main purposes:

• Prevents leaves from sinking into the pond: Decaying leaves can add to sludge and nutrient levels, fueling algae and blanket weed growth. A net makes leaf removal much easier.
• Deters herons: During colder months, herons may become desperate for food and target your fish. A net can prevent these predators from reaching them.

If your pond is near trees or areas with heavy foliage, a net is essential to maintain water quality and protect your fish from unwanted visitors.

3. Monitor Fish Health and Water Quality

Regular checks on your fish are vital during winter. Look for any visible marks or unusual signs of distress. Conduct weekly water tests using test strips to monitor key parameters such as pH, KH, GH, nitrites, and nitrates.

While you can’t control the weather or water temperature, maintaining balanced water parameters ensures a safe and healthy environment for your fish.

For additional support, consider using our winter-specific pond treatment. This bacteria-based product helps break down sludge and debris while maintaining water clarity and health during periods of reduced fish activity.

4. Prevent Your Pond from Freezing

A frozen pond can block oxygen exchange, endangering fish. Here are two effective methods to prevent freezing:

• Pond Heaters: These devices keep an area of your pond ice-free, allowing oxygen to flow and providing a warmer spot for fish.
• Tennis Balls: While less reliable, placing a tennis ball in the water can create a small hole in the ice if the pond freezes. Simply remove the ball to allow oxygen exchange.

For consistent results, prioritize a pond heater, especially during prolonged freezing temperatures.

5. Manage Pond Filters

Deciding whether to leave your pond filter running in winter depends on your setup:

• Advantages of keeping filters running: Moving water is less likely to freeze, and oxygen levels remain consistent.
• Disadvantages: Water exposure to cold air can lower its temperature, potentially stressing your fish.

If you leave your filter running, lift the pump slightly off the pond bottom to avoid disturbing the warmest water layer where fish often rest. Alternatively, if you turn off the filter, wait at least two weeks after stopping fish feeding to ensure their digestive systems are empty. Thoroughly clean and drain the filter before storing it in a dry, sheltered area like a garage or shed.

By following these steps, you can maintain a healthy pond throughout the winter, ensuring it’s ready for spring. Regular maintenance, proper feeding adjustments, and preventative measures will minimize problems and support your pond’s ecosystem.