Unlike indoor aquariums, it's very difficult to control the water conditions of an outdoor pond. For the most part, however, this isn't a problem. After all, those attractive goldfish and koi bred to be kept as pets are descended from wild fish which thrive in varying conditions.
With that said, it's important to be aware of how the temperatures outside can affect your fish. In particular, fish can be at risk of health problems during the colder part of the year. Make sure your pet fish are kept safe by following these tips when the temperature begins to drop.
Adjust your feeding as necessary
Like many animals, fish need plenty of fat reserves to survive cold weather. Look for a feed with high protein content and begin using it towards the end of the summer. This will give your fish the best chance of fattening up enough for winter. When the temperature does drop, so does the ability of fish to digest efficiently. You should offset this by reducing the amount of food you give them.
Monitor the forecast
For obvious reasons, you should look out for any predicted spells of particularly bad weather. If it looks like it's going to reach freezing temperatures or even snow, act fast to make sure your fish are looked after.
Keep the water topped up
If your pond is shallow, there's a higher risk of the water freezing solid if the temperature is low enough. This will kill your fish, so make sure the level is kept topped up as much as possible and monitor it carefully.
Ensure there's plenty of plant life
Pond plants produce oxygen within the water, and that's even more important if there's a chance of freezing over. A layer of ice on top of the water will limit oxygen from outside, so plants are needed to keep the levels up for your fish. Consider adding some new plants if you don't have many.
Keep snow at bay
A covering of snow stops light getting through to the water, which in turn limits the ability of plants to generate oxygen. If it snows, clear it away from the pond as soon as you can.
Create an ice hole
A simple way to keep a gap in any ice is to get a tennis ball or anything else that floats and leave it in the pond. When it freezes over, simply pull out the ball to leave a gap in the ice.
Keep an eye on the fish
People often forget that fish can be taken to a vet, but doing so can often save their lives. Watch out for any strange behaviour and act fast if you're worried.