How to Change Betta Fish Water

Betta splendens, also known as bettas or Siamese fighting fish, are healthiest in a filtered tank with partial water changes every other week. A well-maintained filtered water supply increases oxygen levels and creates a flow of water similar to the natural requirements of bettas. You can also keep a fighting fish in a large unfiltered bowl, but this type of environment is not recommended by fish-keeping experts. Weekly partial water changes are necessary for an unfiltered bowl because fish waste builds up quickly without a filtration method in place.

Things You'll Need

  • Jug
  • Bucket
  • Water dechlorinator
  • Fish net
  • Small bowl
  • Paper towel
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Instructions

  1. Large Filtered Tank

    • 1

      Remove about 15 percent of the water from your tank with a jug. Fish tank water stays healthier if you change a small amount each week. If you replace all of the water at the same time, beneficial bacteria are destroyed and your fish may become sick. You do not have to take your betta out of the tank for a partial water change in a large tank.

    • 2

      Mix the dechlorinator and water in a bucket, following the manufacturer's instructions to neutralize chlorine and chloramine deposits.

    • 3

      Pour the fresh, clean water into the tank.

    Small Unfiltered Bowl

    • 4

      Pour some of the main fish bowl water into the small bowl using a jug.

    • 5

      Catch your betta with the net and release your fish into the small bowl. Place a sheet of paper towel across the top of the bowl so that your betta cannot jump out.

    • 6

      Remove about half of the water using the jug. Unfiltered bowls and tanks produce more bacteria, so a 50 percent water change is necessary to eliminate as much waste as possible without damaging the environmental balance of a small tank.

    • 7

      Mix the water and dechlorinator in a bucket, according to the manufacturer's dosage instructions, so the new water is safe for your betta.

    • 8

      Add the fresh water to the main fish bowl and return your betta to its home.