How to care for koi fry

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How to care for koi fry
Koi fry will grow up to be beautiful, brightly-coloured fish. (Getty Creative)

Koi fry originated in a small county called Niigata in Japan during the early 1800s. Koi are known as "living jewelry" for their variety of beautiful colors such as white, red, yellow, blue, black and cream. Koi come in all different sizes ranging from 7.5 cm to more than 75 cm (3 to 30 inches). Koi fry are a wonderful addition to any pond. Follow these steps to learn how to care for koi fry.

Things you need

  • 250 to 2,200 litre (55 to 500 gallon) stock tank
  • Tank net
  • Microscope
  • Koi fry food
  • Test kits: pH, salt, ammonia and nitrite

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  1. 1

    Set up a quarantine tank for your new koi fry prior to your purchase. Use a net to cover the tank to prevent your koi from jumping out. Don't chance contaminating your fish with your new incoming koi fry. It's cheaper to treat a small quarantine tank than to treat your pond.

  2. 2

    Verify that the koi fry are free of parasites before you bring them home. Some parasites such as the fish louse or anchor worm are visible to the naked eye, but ask for a microscope to inspect the koi fry instead of taking the seller's word for it. Look for moving specks under the microscope -- parasites come in all shapes and sizes from comma-like to circular.

  3. 3

    Feed your koi fry a very small amount after 6 to 8 hours of quarantine. You can use fish pellets or flakes. It's important to remember that two small portions twice a day is better for them than one large portion once a day. Some new fish take longer to adjust and may not eat for a couple of days.

  4. 4

    Observe daily and check for parasites often. If the koi seem to be flopping against things in the pond it can be because they have an itch caused by a parasite. Some parasites cause ulcerations which you can observe without a microscope. If you don't have a microscope, purchase one. Don't treat you koi for parasites until you can identify what type they are carrying. Purchase appropriate treatments at your local pond and fish supply store.

  5. 5

    Check the pH of the water in the tank. Add regular baking soda until your pH test kit reads 7 to 7.5. Add salt after 12 hours. Use 1 gram of salt per litre of water. After first batch has dissolved, use a salt test kit. Your test should read 0.10 percent. Also measure for ammonia and nitrate levels. Levels should read at 0; anything else is unacceptable. Purchase testing kits at your local pond and fish supply store.

  6. 6

    Buy good quality food. It doesn't need to be expensive. Make sure corn is not one of the first five ingredients, as it's a cheap filler that can fatten your koi fry. The first ingredient should always be fish, fish meal or other fish type product.

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