Removing Residual Bleach From Aquariums

Bleach kills all kinds of germs, which is one reason that many aquarium enthusiasts use it to clean their aquariums and the components. If all of the bleach is not removed, however, it is possible that enough residue will remain to contaminate the water, causing the fish to become ill or even die. The best way to prevent such tragedies is to make sure all of the bleach is gone from the aquarium before returning the fish to it.

  1. Reasons for Bleach

    • Bleach is often recommended for disinfecting aquariums because it kills algae as well as any pathogens that might be lurking in the tank. Bleach is also preferred to soap or to detergents because it is more easily removed. Detergents also don̵7;t work well for plastic aquarium plants, gravel or equipment, but bleach can disinfect them all. While full-strength bleach may damage aquarium decorations, diluted bleach won̵7;t and is very effective for cleaning.

    Water

    • One way to remove residual bleach from an aquarium is to rinse it well under a running stream of tap water. Ideally the tank should be placed outside or in a bathtub and a hose should supply a constant stream of water for about two hours. The moving water will rinse the surfaces of the tank and carry away any residual bleach. If running water is not an option, fill the tank with water and allow it to sit for several hours, or overnight if possible. Stir the water frequently or use an air stone to keep the water moving, which will help to remove the chlorine residue.

    Chemicals

    • The best way to ensure that all traces of bleach have been removed from the aquarium is to treat it with a chemical dechlorinator agent after rinsing. Ideally the aquarium should be filled and a strong dechlorinating agent added and left for 24 hours. The aquarium can then be drained and refilled, and the water treated with a regular-strength chlorine removal product.

    Precautions

    • Never use bleach on an aquarium that has fish in it. Also, when using bleach to clean an aquarium, use it at the rate of about 0.5 cups per gallon of water for best results. If used to clean gravel, the gravel must be thoroughly rinsed and stirred during the rinsing process to ensure the residue is removed from all layers. It should also be stirred well once the dechlorinator is added so that all layers of the gravel are exposed to the effects of the chemical.