For the most part, maintaining a fish pond isn’t all that different than maintaining a standard pond, though it is important to ensure the pond remains habitable at all times. Fish require specific water conditions of temperature, oxygen, and pH level. It’s important to ensure that the pond meets these conditions at all times, otherwise the fish will be at risk. For standard pond fish, like koi, the water temperature should be between 59 and 77 F at all times. It’s important for the water to be warmer rather than colder, as the standard koi’s immune system shuts off at temperatures below about 40 F. The water also needs to be oxygenated, and the most common method to accomplish this is with a fountain that stirs up the water. It’s also possible to use a water pump, though this method is less common. Check the pH level of the water on a regular basis, and ensure that the water remains free from bacteria and algae.
These simple fish pond maintenance tips will protect the pond and the fish inside it. It’s also important to be aware of predators including herons, raccoons, cats, foxes, and badgers. The pond should be covered with a mesh, and be free from overhangs. It should also be too deep for a large bird (like a heron) to stand in.