How to Make a Fan Tail Gold Fish Grow Bigger

Fully grown, adult, fantail goldfish have a compact round body that is 6 inches long with a sweeping, elegant, fanned twin tail. Make your pet fantail goldfish grow bigger by giving it a lot of living space with a good-sized aquarium. Fantail goldfish will grow bigger when they are given high-quality food to eat and a well-maintained aquarium with ideal temperature settings in which to swim leisurely. Good food and the right-sized living space can keep a fantail goldfish healthy and encourage its body to grow as much as possible. Good food will also contribute to enriching the goldfish's color.

Things You'll Need

  • Fish tank, 20-gallon or larger
  • Aquarium heater
  • Fish tank gravel stones
  • Bucket
  • Fine-meshed strainer
  • Aquarium decorations
  • Pond plants (optional)
  • Powerful aquarium filter
  • Aquarium water dechlorination treatment
  • High-quality goldfish flakes or pellets
  • Aquarium pH test kit
  • Fish tank lettuce clip with suction cup
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Instructions

    • 1

      Give the goldfish a large, 20-gallon tank in which to live. Goldfish grow bigger in large living spaces. Most goldfish bowls or tanks are far too small for them. The general rule is 1 inch of fish per gallon; however, a fully grown, adult goldfish has a larger body mass than a small, young, 1-inch fish --- it produces more waste and requires more water in which to live. In addition, when gravel, decorations and other items are added to a tank, they displace the water and take up 10 percent of the tank volume. A larger tank also has a larger water surface area, which contributes to better oxygen absorption in the water. Goldfish thrive when their water has a greater oxygen absorption capability, and they have a large space to swim in, which makes a 20-gallon tank ideal.

    • 2

      Install a tank thermometer and a tank water heater. Set the thermometer of the water heater to keep the water at 72 degrees Fahrenheit. Let the water sit for 24 hours.

    • 3

      Rinse off the fish tank gravel stones thoroughly by setting them in a bucket with water. Let them sit for 15 minutes and then pour the stones out into a fine-meshed strainer. Add gravel to the tank bottom that is pea-sized or bigger, as goldfish tend to pick up the stones when looking for food and they may accidentally swallow a smaller-sized stone. Add aquarium decorations for the fish to swim through, such as fake or real plants. If you wish to use pond plants, find plants that are sold in garden centers in stores, such as plants from the Anubias, Crinum and Elodea species.

    • 4

      Keep the aquarium tank water healthy by installing a powerful filter. Goldfish tend to excrete more waste than other types of fish, and they will need a good filter to remove their waste from the water. Remove 1/3 of the water weekly and replace it with pretreated or dechlorinated, room temperature, tank water. Keep the water clean and run the filter constantly to prevent algae build-up on your tank walls and decorations.

    • 5

      Feed the fantail goldfish only once per day. Give it a pinch of food or enough that it can consume within 5 minutes. Feed it specifically formulated goldfish food, such as high-quality goldfish flakes or pellets. The labels of the fish food will tell you what is in the food, so try to find one that has a high percentage of vegetables in it. If vegetables are close to the top of the ingredients list, that indicates that there is a high percentage of vegetables in the food.

    • 6

      Place a lettuce clip with a suction cup attached to the inside of the tank. Putting a fresh leafy vegetable on the clip once a week, such as a piece of lettuce or collard greens and also cucumber slices, will provide extra vitamins for the goldfish, thereby encouraging growth and healthy maintenance.

    • 7

      Monitor the temperature of the water to ensure that the tank water heater is keeping it between 65 and 75 degrees Fahrenheit. The higher temperature range, between 72 and 75 degrees Fahrenheit, is ideal for encouraging growth in your fantail goldfish.

    • 8

      Monitor the pH of the water. Test it weekly with a test kit to ensure that the water is properly filtered and does not contain a high amount of ammonia or nitrates. These two chemicals are toxic to fish and can build up on the bottom of the tank, if the water is not kept clean.