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Stinky Fish Tanks

Why Does My Aquarium Smell, and How Can I Fix It?

(The First Tank Guide)

Most often, an odor from a fish tank is an indication that something is rotting in the tank. This could be:

Odors from the tank can also be a sign of severe overpopulation, which causes excess waste that the filters cannot process.

Insufficient water changes, insufficient filter maintenance, or other shortcomings in tank care can also be a source of odors.

Another possibility is that there is a reaction between some unnecessary chemicals you are using in the fish tank or between an unnecessary chemical and something in the water. I would recommend not using any chemicals in the tank other than a dechlorinator - and maybe a plant food if you are keeping live plants.

What to do:

If you have an odor coming from your fish tank, I would first check to make sure all your fish and other critters are accounted for and alive and healthy. Then check to see if there is uneaten food piling up in or behind decorations or in the filter, or if the filter cartridges otherwise need to be cleaned or replaced.

Make sure you are providing the necessary weekly 10-15% water changes and other necessary tank maintenance including filter maintenance.

Also, reducing the number of unnecessary chemicals that are being used in the tank will probably help your overall tank maintenance as well as helping to prevent unnecessary and undesired odors.




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May 24, 2006
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"Thanks for the help, stopped using ammonia remover and bacteria booster and the tanks have now stabilized. [I] read your articles on the subject after I had sent you the email. It was excellent information. Your site was the only one with this information and had I not found it, my fish would still be smothering in ammonia!! I am really happy now."
November 13, 2004
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