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How to Clean a Fish Tank

Keep your fish healthy and your fish tank clean with these simple steps.


  • Step 1: Use a large plastic cup to remove water from the tank to a large bowl. Scoop fish from the dirty tank and put them in the bowl.
  • Step 2: Turn off the filter on your fish tank. Remove half of the dirty water using a cup, and dump it into a sink.
  • TIP: Change about one quarter of the water in the tank every two weeks to keep the algae levels low.
  • Step 3: Clean the inside of the tank with an algae scrubber. Rinse and scrub until the glass is clean.
  • Step 4: Scoop out the rest of the water until you get to the gravel at the bottom of the tank.
  • TIP: Replace the gravel only if absolutely necessary. The fish need a stable environment, so some remaining bacteria is good for them.
  • Step 5: Refill the tank with clean water and restart the filter. Let the filter run for about an hour.
  • Step 6: Scoop your fish from the bowl to the tank, and let them enjoy their newly cleaned home.
  • FACT: Did you know? Scientists discovered the world's smallest fish in Indonesia. A member of the carp family, it's less than eight millimeters long.

You Will Need

  • A large plastic cup
  • A large bowl
  • A scooping net
  • A sink
  • An algae scrubber
  • Clean gravel (optional)

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