For proper goldfish bowl maintenance, goldfish owners must change the water out almost daily due to the large amount of waste and ammonia goldfish produce. Though it is possible to maintain a fish bowl if a tank is not an option, it is recommended that to place them in a tank that carries at least 6 gallons, but does not exceed 10 gallons.
To extend the time in between cleaning periods, place gravel bits or some living plants for cleaner water. Because a goldfish bowl is small, owners should limit the algae content to allow space for the goldfish. Additionally, maintain the algae at a temperature of around 77 degrees Fahrenheit, which is too high for goldfish to live comfortably, though a small amount of algae is okay to use. Ideally, goldfish thrive in temperatures between 65 to 68 degrees Fahrenheit, and should not live in water temperatures that exceed 74 degrees Fahrenheit.
To clean the bowl, remove between 50 to 75-percent of the water in the bowl, and add clean water without chlorine. To ensure there is no chlorine within the water, add dechlorinator. If the process is done quickly, the goldfish can stay in the bowl during the water change. While cleaning the bowl, be sure to remove any algae with a rag or an algae scrubber, which is purchasable at a local pet store. Add a drop of dechlorinator after the process is over.
To maintain the health of a goldfish, provide it with a food once a day that is rich in variety and carbohydrates, and avoid overfeeding them. Goldfish should be able to finish their food in two minutes or less. Excess food in the bowl can cause water contamination and put the goldfish at risk for disease.