Q: TA wrote, A few weeks ago my betta died from Dropsy (I think) and I want to get a new one. How do I sanitize my aquarium so that my new betta doesn’t pick up the germs? Is bleach safe to use in an aquarium?
A: Bleach is one of the safest and most effective methods for sanitizing an aquarium before the initial set-up. Many people are afraid to use bleach because they are afraid of its potency but actually it is perfectly safe if used correctly. We use bleach for sanitization because it is one of the most successful chemicals we have for disinfecting. It is commonly used in U.S. hospitals and is recommended by the Center for Disease Control. Bleach or Sodium hypochlorite (NaClO), is also safe for the environment. It breaks down very quickly, leaving mostly salt and water behind. Because it is a strong disinfectant that breaks down into harmless byproducts rapidly, it can be used to sanitize baby and pet toys, aquariums and yes it is even used to sanitize our water supply.
How to disinfect your aquarium with bleach.
- When buying bleach for aquarium cleaning, only use regular bleach like Chlorox Regular Bleach or an equivalent. Do not use bleach mixed with detergent. Detergents leave dangerous residue that can be fatal to aquarium fish.
- Using a typical household bleach (which is already about 5% bleach) mix 9 parts water with 1 part regular bottled bleach. I like to store it short term in a spray bottle purchased at my local hardware store. Note that bleach does break down fairly quickly so only make small quantities at a time. Never store bleach in a bottled previously used with other chemicals.
- Wipe any debris from the aquarium with warm water and a paper towel.
- Spray all surfaces of the aquarium with the 10% solution you have just created. I like to do this in my bathtub to contain the overspray. Sanitizing outdoors is also a good option.
- Let the aquarium sit for 10-15 minutes. Bleach is a corrosive chemical and can cause damage to your aquarium if left too long. Do not allow it to sit for longer than 15 minutes.
- Rinse thoroughly. When you are done rinsing, rinse again for good measure.
- Allow the aquarium to air dry completely. This will help to insure that the bleach solution has broken down into harmless byproducts.
- Once you set up your aquarium, fill the tank with water and dose with a good aquarium water dechlorinator.
Aquarium gravel, decorations, filters, heaters, etc. can also be bleached using the same concentration of water to bleach. You can either spray them or soak them in a bowl depending on what you are cleaning. Just be sure to rinse very well and allow everything to air dry completely before putting back in the aquarium. Note that metal rusts quickly when exposed to bleach. As mentioned earlier, never allow bleach to sit on the item for more than 10 – 15 minutes.
IMPORTANT SAFETY INFORMATION:
Bleach can be very dangerous if inhaled or ingested. It can cause moderate to severe damage if it comes in contact with the eyes or skin. It can also cause discoloration or corrosion of some materials. Please view the International Chemical Safety Card(www.ilo.org) before using bleach.