Routine cleaning of an aquarium, including the gravel, is a vital part of maintaining the health of the fish that live in the habitat. Disinfection of aquarium gravel may become necessary due to the overgrowth of bacteria that are harmful to the fish. Under these circumstances, the procedure should be performed as a part of disinfecting the entire tank and its contents. Disinfection should also be conducted if the gravel had been previously used in a different fish tank. Regardless of the situation, disinfecting aquarium gravel with chlorine bleach is relatively easy to perform.
Wear the protective eyewear and disposable gloves. Also be aware that bleach can discolour clothing if it comes in contact with it.
Add a cup of bleach and 19 cups of water to a bucket. This makes 1 ¼ gallons of bleach solution that has a dilution of 1 to 20. Depending on the amount of gravel present, more bleach solution may be required. Under these circumstances, for every single portion of bleach, add 19 portions of water.
Pour all of the gravel into the bucket with the bleach water. Be careful to prevent splashing of the water onto your clothes or face. The water should completely cover all of the gravel.
Allow the gravel to soak for at least 30 minutes.
Pour off the bleach solution and thoroughly rinse the gravel with tap water. Repeat this process a few times to be sure that all bleach residue is removed from the gravel. Be sure that the gravel is free of any debris or dirt before continuing.
Place the gravel in a clean tank, and add decorations and water. Also set up the filter and other equipment, such as an air bubbler and/or heater.
Add chlorine/chloramine removal drops to the aquarium. Doing so prevents any residual bleach, as well as the chlorine in the water from harming the fish.
Allow the water in the tank to cycle through the filter for 6 to 24 hours before putting the fish back into the aquarium.
If the gravel is new, disinfection is not necessary. Under these circumstances, simply rinsing the gravel with water is sufficient.
Failure to add the chlorine/chloramine removal drops to the water after refilling the tank can result in harm, and even death of the fish. If the gravel is new, disinfection is not necessary. Under these circumstances, simply rinsing the gravel with water is sufficient.