How to Change Goldfish Tank Water

Change the water in your goldfish tank to ensure your pets stay healthy.
Change the water in your goldfish tank to ensure your pets stay healthy. (Image: Goldfish image by Lucy Cherniak from

Goldfish make terrific first pets. They are affordable, entertaining to watch and require only moderate care. The only difficult aspect of raising goldfish is maintaining a clean tank. Dirty water promotes disease and can lead to upside-down goldfish floating in your tank. You should change, or “cycle,” a percentage of the water every week instead of waiting for the tank to become extremely filthy. Changing all of the water at once disturbs the chemistry in the tank and jeopardizes the health of your goldfish.

Things You'll Need

  • Cup
  • Siphon
  • Chlorine-removal solution
  • Water-testing kit

Leave the goldfish in the tank while you change the water. Removing the goldfish and putting them in another container during the cycling process stresses them and could even kill them. If you have any plants in the tank, leave them in as well.

Use a cup to remove 10 to 20 percent of the water in the tank. It’s important not to remove too much water at one time, because goldfish require a consistent chemical and biological environment. Replacing too much water at one time alters this environment.

Use a siphon to clean any waste buildup from the gravel and any artificial plants you may have placed in the tank.

Fill a clean container with approximately the same amount of water you removed from the tank. Add chlorine-removal solution to the fresh water. Be sure to read and follow the instructions on the package to determine how much of the solution to add to the tap water.

Test the pH levels of the dechlorinated water with a water-testing kit before adding it to the goldfish tank. Follow the directions carefully to ensure you use the water-testing kit properly and understand how to interpret the test results.

Add the dechlorinated water to the tank. Fill the tank to within 1/2 inch of the top.

Repeat the cycling process on at least a weekly basis. Since you remove 10 to 20 percent of the water with each cycling, you will eventually change the entire tank water every five to ten cycles. The cleaner you keep the tank, the healthier your goldfish will be.

Related Searches


Promoted By Zergnet


You May Also Like

Related Searches

Check It Out

How to Make an Elevated Dog Feeder

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!