While most tropical fish require an aerated aquarium to keep them healthy, there are some fish species, such as Betta fish, some gouramis, the paradise fish, and a few other species that can live in an unaerated fishbowl. Even small fish do best in a bowl that is at least half a gallon in size, or bigger. Just as it is important to keep any aquarium clean, it is even more important if you keep fish in a fishbowl, since these containers usually do not have filters and the small water volume means that contamination is more concentrated. It is especially important to clean fish bowls weekly because failing to do so can quickly result in disease and death to fish.
Materials You Will Need
Assemble these items:
- Clean two-cup container
- Water conditioner product (dechlorinator)
- Small fishnet
- Hand towel
- Paper towels
- A small brush (toothbrush)
- Aquarium thermometer
- Water test strips or kit
Prepare the New Water
Unlike large tanks, where a portion of the water can be replaced with each cleaning, cleaning a small bowl usually means replacing the entire water supply. To avoid major shock to your fish, it's critical that the water is treated to remove harmful substances in tap water, such as chlorine or ammonia, and checked to be sure it is at the appropriate temperature and pH.
Regardless of what your water source is, it should be treated to eliminate chlorine, chloramines, heavy metals, and other potentially harmful substances. Maintaining a consistent water temperature is also important to avoid stressing the fish with an abrupt temperature change. Lastly, tap water contains dissolved gases that dissipate after a short time, often changing the pH of the water, which is another stress factor for your fish. All of those issues can be addressed by testing and treating your water before adding it to the fishbowl.
The process for aging water is a simple one:
- Fill a clean bucket with water from the tap. Use your aquarium thermometer to measure the temperature and adjust it to the correct temperature for your fish (usually 72-78 degrees F). You should buy a bucket to be used only for fish water, to ensure that it never contains any soap residue.
- Add a water conditioner product. Choose a product that is advertised to instantly remove chlorine, neutralize chloramines, and detoxify heavy metals.
- Test the water using water test strips or a test kit to ensure it has no chlorine, ammonia, nitrite, or nitrate and the pH is about 7.0-7.8.
After the new water has been prepared, you can proceed to clean the fishbowl.
Remove the Fish
While cleaning the fishbowl, you will temporarily move your fish to a container filled with water taken from the fishbowl. Using this water will minimize shock to the fish.
- Take some of the existing water from the fishbowl and fill a small, clean container that has never been washed with soap.
- Net the fish out of the bowl and place them in this container.
- Fish that normally don't jump will behave differently under stress, so your fish might try to make a break for it. Reducing the light will also help reduce stress to the fish. Place a hand towel over the container to reduce the light and keep the fish from jumping out.
Clean the Fishbowl
Proceed quickly to cleaning the fishbowl, as you want to minimize the time your fish spend in the temporary container.
- Remove all the decorations and place them on a clean surface or paper towels.
- Place a clean strainer in the sink, then pour the water out of the bowl through the strainer, catching the gravel.
- Set the bowl aside and rinse the gravel with warm water, shaking it several times to ensure all debris is washed out.
- While the bowl is still damp, use paper towels to scrub the inside surfaces of the bowl. Do not use soap or other detergents.
- If there are stubborn stains on the bowl, use a small clean brush to scrub the stains. A new toothbrush works well for this. The same brush can be used to scrub the decorations.
- Rinse the bowl and decorations several times with warm water.
Reassemble the Fish Bowl
All that remains is to reassemble the bowl, add the new water, and invite your fish back into their clean home.
- Place the cleaned gravel in the bottom bowl, distributing it evenly over the bottom.
- Arrange the decorations as desired.
- Next, fill the bowl with the prepared water. Adjust the decorations if needed.
- Net the fish out of their temporary container and return them to the clean fishbowl.
- Use a paper towel to wipe away any water on the outside of the bowl.
- Feeding your fish sparingly will help keep the bowl cleaner between maintenance days. Overfeeding is the most common mistake fish owners make. Usually fish only need as much food as they will eat in three minutes twice daily. There should never be uneaten food left on the bottom of the bowl or aquarium.
- Keep a couple of water jugs filled with treated water so you always have prepared water available for emergency water changes.
- Use vinegar if your fishbowl has lime marks after cleaning. Lay the bowl on its side and place enough vinegar in the bowl to cover the stained area. Let it sit for 15 to 30 minutes, then scrub with a clean brush.
- For stubborn algae stains on the fishbowl or decorations, clean with a 10 percent bleach solution. Make the solution by combining nine parts of water with one part bleach. Soak the bowl and decorations in the bleach solution for 15 to 30 minutes, then rinse several times with cool water and allow the bowl to air dry.
Disinfection With Chloramine. Centers for Disease Control and Prevention, 2020