Feed your goldfish a daily diet of goldfish pellets designed for pond fish. Follow the package labeling for allocation amounts. Refrain from feeding the goldfish when the temperature of your water feature drops below 55 degrees Fahrenheit or when the temperature is above 90 degrees Fahrenheit.
Maintain a pH level between 7.0 and 7.8 at all times. Keep nitrate and ammonia levels at 0.0. Perform a water test weekly to determine the pH, ammonia and nitrate levels. Follow the instructions on the testing kit if the water in your water feature requires adjustment.
Poke a hole in the ice if the water in your water feature freezes over the winter. Form the hole by pouring hot water over the ice. Simply fill a teakettle or pot with hot water and pour it over any section of frozen water. The hole will allow for oxygen and carbon dioxide exchange in the water feature.
Provide your goldfish with protection from the sun. Plants overhanging your water feature or a plank placed across the middle of the water feature will provide the necessary shade that goldfish need.
Place an aerator in the water feature to keep the water moving. Stagnant water is a breeding ground for bacterial growth. An aerator will also ensure that your water feature maintains healthy oxygen levels for your goldfish.