How to Take Care of Adult Goldfish

Say "goldfish" and most people immediately picture little cheesy crackers, or a small, orange fish in a plastic bag being handed over as a prize, by a clown. In truth, goldfish make excellent pets. If you purchase healthy ones from a reputable dealer and care for goldfish properly, they can live for 20 years. It's no harder to maintain adult goldfish than any other tropical freshwater fish, but if you think all you need is a bowl and a fern, you are mistaken. Maintaining adult goldfish requires a commitment, just as any other pet does.

Things You'll Need

  • Aquarium, at least 20-gallon size
  • Heavy-duty filter system
  • Medium-sized substrate
  • Rocks
  • Woodwork
  • Plants, preferably java ferns and cabomba
  • Water
  • Fish food
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Instructions

    • 1

      Make sure your tank is big enough. It should hold at least 20 gallons of water for one fish, and another 10 gallons for each additional fish. It should also have a tight-fitting lid, and a light. Goldfish do not necessarily need a heater, unless your home is warm during the day and very cold at night. Adult goldfish don't like extreme temperature changes in a 24-hour period.

    • 2

      Make the tank interesting for your goldfish. Provide hiding places like aquarium driftwood and plants. Goldfish like to chew on plants so choose hardy varieties of aquarium plants like java ferns. Adding a clump of cabomba as a treat every once in awhile will keep your goldfish happy.

    • 3

      Provide adequate filtration. Goldfish produce a lot of waste, so you need a heavy-duty filtration system. This needs to be cleaned thoroughly at least once a month to keep the water clear and healthy.

    • 4

      Keep the water fresh. Remove and replace at least 25 percent of your goldfish tank's water every week. This helps remove waste and add oxygen, which adult goldfish need to thrive.

    • 5

      Feed your goldfish well. Goldfish are omnivorous, which means that they need both vegetable and animal products. Feed them small meals of specially formulated goldfish food a few times a day. Soak the food in water before feedings to help the goldfish digest it. Add frozen vegetables, spinach, hard-boiled egg yolk, earthworms and brine shrimp to keep your adult goldfish sleek and healthy.

    • 6

      Give your goldfish someone to play with. Several goldfish in a tank will keep each other company. Just make sure that the tank is big enough to accommodate them all.