The main reason why fish must not be kept in a bowl is that the fish have a lateral line – a row of holes on the side of the fish’s body, these holes lead to tubules that connect to the sensory receptors, which together form one of the most sensitive sense organs.

Many aquarists probably started their aquarium hobby by breeding guppies in a cucumber jar. However, a very dangerous phenomenon has recently become the presentation of goldfish bowl for all occasions. While for the recipient the gift may turn out to be a pleasant gesture at the beginning, trouble begins after a few days. In this article you’ll find more informantion why bowls are bad as a place to live for even one goldfish.

Requirements of aquarium fish

Each living creature requires appropriate living conditions. It is not only about food, but also about a suitable swimming space. While setting up a new fish tank, be aware that different fish species have different requirements regarding water quality and swimming space. A bowl for the proverbial “gold fish” is absolutely not a suitable home. The veil tails in question require a fish tank of at least 40 litres, and some keepers believe that 20 litres more per individual. Additionally, efficient filtration is necessary, because these fish produce quite a lot of metabolic products that affect the water quality. It will also be necessary to properly oxygenate the aquarium, e.g. by the movement of the water surface. Gas exchange is more difficult in case of small water surface. The more place in the aquarium we have, the more swimming space our fish have. Moreover, there is more space for live plant s which are very helpful during the nitrogen cycle. To sum up- it’s easier to maintain high water quality in a larger fish tank equipped with live aquartic plants than in a fish bowl with artificial decorations and unfiltered fish waste.

The problem of filtration

In the tiny bowl, we are unable to provide any of the above requirements. The fish bowls usually have a capacity of up to several litres, so much too little for the species in question. Due to the shape of the sphere, we will not be able to provide the fish with proper filtration. There is no point in deluding ourselves that the sub-gravel filters that are often added to the sets will do their job. This is usually an advertising gimmick to ensure that the potential customer is providing the keeping fish with the bare minimum.

The problem of cleaning

There is also the question of aesthetics. There is nothing to count on that the spherical “aquarium” will be clean all the time. Veiltails are definitely not cleaners and can cover the bottom of the small bowl with their droppings very quickly. The filters mentioned above will of course not be able to remove fish waste.

In the case of the fish bowl, cleaning the glass walls is also extremely difficult. The small upper opening is unlikely to allow us to manipulate the hand, not to mention the possibility of crushing our only fish. Thus, cleaning a spherical aquarium usually ends with transferring the golden pet to the bucket and replacing all the water. And this, of course, is a breach of another aquarist rule, because in this way we will never achieve even a substitute of biological balance in the tank. Aquarium fish need healthy environment for balanced developement and the water quality is the cherry on top in any aquarium. Learn how important the frequent water change is with our blog here.

Less space for waste = more cleaning

In the case of veil tails breeding, it is sometimes necessary to clean the bowl after 1-2 days. Of course, it ends with the frustration of the “aquarist” and less enthusiasm to have a water tank with living creatures. And if due to insufficient filtration, and no water changes, the fish in bowls will quickly swim in its own waste.

Additionally, after some time, a white coating that is difficult to remove will appear on the walls of the fish bowl. This significantly reduces the already dubious attractiveness of the tank and will make an impression of dirty water.


The above reasons are just a few AGAINST keeping a fish in small bowls. Fish bowls are bad for any fish so we would recommend larger tanks even for a single goldfish. Therefore, it is worth making friends aware that “fulfilling 3 wishes” in a goldfish bowl is not a good gift idea. Unfortunately, the manufacturers of such fish bowls often advertise their products as intended for these animals, but of course, it is only an advertising gimmick of the pet stores. Investing in larger fish tank doesn’t mean much money and for sure will be easier to maintain water quality. If you’re not into large tanks, you can try to set up a Nanotank – a small tank which origins from Asia. It’s cubic shape will definitely allow you to keep your fish tank clean. Change water frequently, control the fish food amounts, choose small fish that will do in such a small space. Just keep your fish in healthy environment. Then ask your gold fish or betta fish if that was a great deal 😉 We think thet will completely agree.

Leave a Reply