It’s not usually recommended to completely clean out your entire goldfish aquarium but sometimes some serious spring cleaning needs to be done for proper goldfish care.
During this cleanings you might want to set up a temporary home for your goldfish to lessen the stress they might experience. Use some of the water from the tank you plan on cleaning and place it in your temporary goldfish tank. Next, use a plastic container to scoop up the fish. To avoid any injuries to your goldfish, only use a net if you have to.
First unplug everything to avoid any potential electric shock
Remove all your goldfish accessories and rinse them off in a sink. Then fill the sink with hot water and allow all of your ornaments to soak. Allow them to soak for the entire time you are cleaning your goldfish aquarium. To be safe, don’t use any cleaning products or soap on your goldfish accessories.
If you have any potted living aquatic plants, dig them up and move them to one side of your tank or place them in a temporary tank so they will be out of the way when you clean the aquarium glass, gravel and filters. Being careful not disturb any roots, scrub off any algae growth that might have accumulated on any drift wood or rocks that have aquatic plants attached to them.
Using your algae scrubber, scrub down the sides and corners of your aquarium glass. You might need to use some elbow grease to get it off or a razor blade (use a plastic blade on acrylic tanks) to get the extra algae off. Some algae is beneficial; leaving a tiny bit behind will actually add to aquarium’s health.
When all you have left is a gravel bottom, use an aquarium gravel cleaner to suck up all the dirt, waste and water into another bucket. Go slowly through the gravel moving the gravel cleaner over an inch every two seconds. If you don’t have a gravel cleaner, use your hands to mix up the gravel and free any dirt and waste. Then use a siphon hose or bucket to remove 15-20% of the water.
Don’t remove the gravel and rinse it off like you did when you first introduced it to your goldfish aquarium. In an established tank, beneficial bacteria that help regulate the nitrogen cycle have grown and you don’t want to eliminate them from your tank.
Take out your aquarium filters and clean them in the bucket of dirty aquarium water. The filter has these beneficial bacteria too so a few shakes to remove all the debris and a few squeezes of the filter is all you need. But, depending on the filter media, wait a few weeks to make sure the beneficial bacteria in the gravel is back to its pre-cleaned levels and then change the the filter media. If your aquarium filter contains carbon, ion-exchange resins or ammonia absorbers, you should change them every three weeks or so.
You can now complete the aquarium water change in your goldfish aquarium by using tap water and some dechlorinator to eliminate the chlorine. Make sure the water temperature is back to the temperature of what the tank was before cleaning. Place your decorative goldfish accessories back into your goldfish aquarium and then carefully place your goldfish back into their aquarium.