The Two Gallon Fish Bowl: Cool, or Cruel?

Cruel or Cool? The Fish Bowl

The two-gallon fish bowl is ubiquitous in our society and has seen the residence of literally billions of Koi, goldfish and pond fish. I would estimate that almost all of us have had a two-gallon fish bowl. The original fish is usually some hapless Comet Koi, goldfish and pond fish which lives for about a week. The reason it died is that your fish bowl had no filtration system, and therefore no bacteria to reduce the excreted nitrogen from the food it was (over)fed. Ammonia surged and killed the fish. No one knew to test this parameter.

So, you buy a second fish, which lives a week more, then dies of Ammonia poisoning despite water changes.

Eventually, a Comet survives because enough beneficial bacteria have colonized the gravel and plastic-plant to reduce the Nitrogen. You may have fed less frequently by this time as your childhood enthusiasm for Koi, goldfish and pond fish waned.  Roman numerals get confusing as you get out to Beloved Koi, goldfish and pond fish George the XIII

Just as you begin to breathe a sigh of relief that “this one” is going to make it, you buy him a “friend” and you don’t know to do any kind of quarantine. The new one and your old one perish when they get Ich. You use “Ich-Be-Gone” with Formalin, which kills off that little bit of beneficial bacteria on the plant, and you’re into another Cycle when you restock.

After another full cycle and ten more “Georges” you finally get another fish to survive, and you decide that “new friends” are a bad idea. This particular fish actually does fairly well and starts to grow. It eats algae on the sides of the bowl and starts to get kind of big.

Eventually, it gets cramped and the fins start to curl. Cataracts develop when the fish is only four years old and the skin turns pale for lack of real sunlight. The spine begins to curve for lack of space and because of the refined flake food diet. By the time the fish is five years old, it has undergone years of chronic stress due to its own crowding. It’s only grown to be six inches long and finally perishes at the age of five-and-a-half looking like a geriatric specimen.

I am not so rabid as to call for the “outlaw” of the two-gallon fish bowl. In fact, it is not the manufacturer of the fish bowl who has committed the ‘wrong’. It is our responsibility to educate as many people as we can about the proper way to keep Koi, goldfish and pond fish. We can do it with helpful support, not condemning attacks. We can do it with understanding, not intolerance. Folks using fish bowls have not ‘seen the light’ and enjoyed the pleasure of having fish in larger facilities.

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Dr Erik Johnson

Dr Erik Johnson is a Marietta, Georgia Veterinarian with a practice in small animal medicine. He graduated from University of Georgia with his Doctorate in 1991. Dr Johnson is the author of several texts on Koi and Pond Fish Health and Disease as well as numerous articles on dog and cat health topics.