Keeping a Fish Bowl

(and small tanks, vases, urns, or buckets)

Contrary to popular opinion, fish bowls and vases are NOT easy to care for. In fact, it becomes easier to care for aquatic pets the larger the environment (tank or bowl) you keep them in. However, other factors play a part in how much water you can keep in a bowl...

If you choose to keep fish in a bowl, there are several things you should keep in mind. Fish kept in bowl will continue to produce waste as they consume food, and any excess food that gets into their tank will still begin to decay. Decaying food, fish waste, and debris that falls into the tank from the air will all contribute to poor water quality, and can eventually reach toxic levels. In a small environment like a bowl, this problem is compounded by the small volume of the water. In larger environments, there is more water to dissipate these toxins.

Keep the water in your fish bowl low. The water level should be near the widest part of the bowl to optimize the surface area where Carbon Dioxide can be released into the atmosphere and Oxygen can be dissolved into the water. Remember that lowering the water level also decreases the water volume in the bowl, thereby decreasing the ability of the water to dissipate fish waste and other toxins and lowering the fish capacity of the bowl.

Basic Fish Bowl Maintenance

In a typical fish bowl, you should change about half of the water every day or every other day to remove these waste products before they reach toxic levels. Yes, this is a larger water change and more often than we typically recommend, and yes, it is stressful to the fish, however, this stress is less threatening to the fish than not changing the water. Many people find it beneficial to have a second bowl handy and transfer the fish from the dirty bowl to the clean bowl frequently. This gives the bowl owner an opportunity to clean fish waste, debris, and excess food out of the gravel and decorations in the dirty bowl while minimizing the stress on the fish.

How do I Reduce My Fish Bowl Maintenance?

There are several things you can do to reduce the care requirements of a bowl.
First, get a top for the bowl. Having a top on your bowl reduces water loss due to evaporation and reduces the amount of debris that collects in the water from the environment. Tops are available for many sizes of bowls and most small tanks.
Second, get a filter for your bowl. There are box filters (both powered and unpowered), sponge filters, and under gravel filters available that are small enough for fish bowls. Most people find the sponge filters and corner filters to take up too much room in their bowls, and opt for the under gravel filters. If you are using a filter in your bowl, remember that the filter will need maintenance as well, and should be cleaned or have cartridges changed regularly. For an under gravel filter, this means either vacuuming the gravel when you do water changes or stirring up the gravel to free the debris caught in it so you can remove this debris when you do your water changes.
Third, agitate the water in the bowl. This can easily be done with a small water pump or an air pump. This will make excess food and other debris more visible so it will be easier to tell if you are over feeding your fish or if there is other debris collecting in the bowl. This also makes it easier to see the debris in the tank so you can more readily remove it when doing your water changes. Additionally, this increases the surface area greatly, improving gas exchange. In most cases, having a filter in your bowl agitates the water sufficiently.

In a bowl where you have provided maximized surface, are agitating the water and providing filtration, and have the bowl covered, water changes can usually be reduced to twice weekly. However, remember to watch your fish for signs of ammonia stress (gasping at the surface, lethargy, loss of appetite, loss of color, and inflammation of the gills, eyes, and possibly fins) or excess debris in the water, such as fish waste or uneaten food, and perform extra water changes as necessary.

Feeding

Feed your fish sparingly. The most common reasons for premature fish death in the hobby are over feeding and inadequate maintenance. Feed your fish only once a day, and in a bowl, only what they COMPLETELY consume in under a minute. Excess food in the bowl will begin to decay, and in the limited capacity of a bowl, the water can become toxic rapidly. Feed your fish a variety of quality fish foods—feeding only one food presents the possibility of a vitamin or mineral deficiency, and the number of quality foods available on the market today allows every pet owner to provide a selection of high quality foods for their fish.

Fish Bowl Capacity

Possibly the most frustrating thing about owning a fish bowl is the limited capacity for fish. In a filtered bowl, we recommend keeping only 1" of fish for every 1.5-2 gallons of water in the bowl—remember that the bowl is probably holding substantially less water than its total capacity since you are keeping the water level lowered to the widest part of the bowl—usually 1/3-1/2 of the bowl's capacity is air, not water. If you are not filtering your bowl, we recommend keeping your population at 1" of fish for every 3 gallons of water or lower. Remember that a fish's size is not determined by the environment it is kept in, but rather is controlled by genetics. The small fish you purchase for your bowl today may be a very large fish by the time it is mature. Keeping a fish in an environment that is too crowded or too small is cruel and can lead to a wide variety of health problems from reduced immune systems to crippling skeletal deformities or failure of internal systems.

Conclusion

Diligent maintenance of a bowl, monitoring your fish for problems and addressing them as soon as they arise, and insuring that your bowl provides sufficient space for your fish can provide an environment where your fish can remain healthy for years. Though a larger environment is always healthier and less work, a well-cared for bowl can be an attractive accent to any home or office.

My snail mail address is: Keith Seyffarth, 217 W. Koch, #308, Bozeman, MT 59715.
Thank you for your support.
Page most recently modified: August 13 2006 11:07:28.