What Is the Best Fish to Keep in a Fishbowl?
Why Keeping Fish in a Fishbowl Can Be a Challenge
Most fishbowls do not provide an adequate habitat for most aquarium fish. Many people consider putting fish in small bowls to be animal cruelty that should be avoided at all costs since there are many challenges that come with a bowl’s living environment.
In general, the smaller the aquarium the more difficult it is to keep the fish that live there healthy. Water chemistry and temperatures can change much more rapidly in a smaller aquarium making fish in small aquariums or fishbowls more difficult to care for.
Fishbowls and small aquariums are not recommended for beginners due to the difficulties associated with keeping fish in them. It is best to start with the largest aquarium your budget and space allow. Ideally, start with a 30-55 gallon aquarium. Although keeping fish in small aquariums or fishbowls is more difficult, it’s not impossible. There are some fish that do quite well in a bowl when properly cared for.
In this article, we will go into detail about:
- Commonly kept fish that should never be kept in a fishbowl.
- The challenges of keeping fish in a bowl or small aquarium.
- How to create an environment that helps keep your fish healthy.
- Fish that do well in bowl environments.
Things to Consider for Your Fishbowl
Here are some other factors that you should think about when choosing the size of your fishbowl and what fish to put in it.
1. Appropriate-Sized Fish for a Fishbowl
Your fish needs to have enough room to be comfortable in its environment, so you should think about the size of your dream fish in relation to the fishbowl. In general, the larger the fish, the larger the living space needs to be, and having more than one fish creates a need for even more space.
Large fish such as goldfish can create too much waste for the bowl to handle, causing a problem with ammonia and bacteria. While size is a huge consideration (no pun intended), there are several other factors that need to be considered before purchasing a fish or deciding on the size of a tank or fishbowl.
2. The One-Inch-Per-Gallon Rule
The one-inch-per-gallon rule is often misunderstood. It actually applies to the square inches of a fish and not to the length of the fish.
In order for the formula to work properly, the tank must be well-maintained with a good filtration system. In most cases, it should get partial water changes (1/4–1/3 of the total volume) every 2–4 weeks.
Take guppies, for example. Guppy dimensions are typically 1–1/2" x 1/2" x 1/4", which works out to around 1/5th gallon per fish. Using this rule, you would be able to keep approximately 4–5 fish per gallon.
This rule does not apply to all fish. For example, a four-inch-long goldfish would be approximately 4" x 1–1/2" x 1" or approximately 6 square inches. That would make a 6-gallon tank seem quite reasonable until you consider the amount of waste a typical goldfish produces and how quickly a goldfish can grow.
Have you ever tried to keep Goldfish in a bowl only to have the water go cloudy and have the Goldfish die?
3. Tropical Fish and Aquarium Temperature
Most fish that you might want to put in a bowl fall in the category of "tropical fish."
Although not all fish that are considered tropical are from the tropics, the majority of tropical fish need to be kept in an environment that stays within a specific temperature range, typically between 70 and 78 F.
This is not true for all tropical species as some require higher temperatures, and others require lower ones for the fish to thrive.
While the range is very important, it's also important that the temperature stays consistent. The smaller the tank or bowl, the faster the water temperature changes due to conditions in the room.
Rapid temperature changes can stress fish and make them more susceptible to disease and parasites.
4. Aquarium Filtration
Aquarium filtration is one of the most misunderstood parts of keeping an aquarium. Even experienced fish keepers may have some difficulty with aquarium filtration.
The reason it can be so difficult is that there is no one size fits all solution. Every aquarium is different. The size of the tank, number of fish, the way they are fed, water chemistry, temperatures, lighting, number of plants, type and amount of substrate and more, all have an influence on what type and how much filtration is needed.
Many new aquarium hobbyists think that the purpose of an aquarium filter is to remove particles and debris from the aquarium water. Removing debris from the aquarium water is only part of what a good aquarium filtration system should take care of.
Mechanical filtration is a filtration process that helps to remove particles in the water. These particles can sometimes be seen in the water as small pieces of debris or they can be so small that they simply discolor the water or make it cloudy.
Simple mechanical filtration can be achieved by using some kind of material such as filter floss pads, cloths or sponges to remove particles from the water. As water passes through the filter media it gets trapped inside. Eventually, the filter media gets filled with trapped debris, water can't flow through the filter as well and it becomes less effective. If the filter media gets filled with debris it needs to be cleaned or replaced.
Chemical filtration is used to take out the dissolved contaminates that are in the water that are too small to be removed with mechanical filtration.
The most cost effective method to remove those microscopic particles is to use activated carbon. Activated carbon has very small pores in it that help to trap tiny particles. The activated carbon eventually gets saturated with debris and should be changed.
Most hobbyist recommend changing their activated carbon about once a month depending on the number and type of fish that are kept in the aquarium.
There are other types of chemical filtration available besides activated carbon.
A relatively new product called Purigen, made by a company named Seachem, is marketed as a product that leaves your water crystal clear and can be recharged and reused.
Biological Filtration in an aquarium refers to the process of using beneficial bacteria to break down waste to help make the water safer for fish. Earlier in this article, we asked the question "Have you ever tried to keep Goldfish in a bowl only to have the water go cloudy and have the Goldfish die?"
The likely reason for the water getting cloudy and having the fish die is due to an improperly cycled tank. In order to understand how biological filtration works one should have a good understanding of the nitrogen cycle.
New Tank Syndrome
A fish tank that has not been properly cycled can develop what is referred to as "New Tank Syndrome". Wastes, excess food, decomposing plants, etc all contribute to producing ammonia in an aquarium. If there aren't enough bacteria in the aquarium the levels of ammonia can rise to a point that fish can develop tissue and organ damage which can lead to poor growth, illness, and death.
What Is the Nitrogen Cycle?
When an aquarium has a good nitrogen cycle working in it, the aquarium is said to be "cycled". This process can take as long as three months, even longer if the process is interrupted by water changes or chemicals. Water temperature is also an important factor and should be kept in the high 70s° to low 80s° Fahrenheit.
Nitrogen compounds are produced from the waste coming from fish, uneaten fish food, decaying plant matter and other organic matter that is breaking down in the aquarium. The concentrations of nitrogen compounds found in an aquarium are ammonia, nitrite, and nitrate. While all three nitrogen compounds are harmful to fish, ammonia and nitrite are highly toxic.
The nitrogen cycle is the process that nature uses to break down these toxic nitrogen compounds.
Highly toxic ammonia is produced as waste and excess food is broken down by bacteria. In a healthy, cycled aquarium, Nitrosomonas bacteria oxidizes ammonia into nitrite.
Fish can withstand nitrite much better than they can ammonia however it is still quite toxic to fish. Nitrobacter bacteria, in turn, consume nitrite and release a less toxic nitrogen compound called nitrate.
Nitrate is much less toxic to fish than ammonia or nitrite however nitrate can build up in an aquarium over time. Nitrate levels can be reduced by doing periodic partial water changes. How much water and how often it should be changed depends on how much waste is being produced in the aquarium and the size of the aquarium.
Note: Never empty the aquarium all the way unless the water in the aquarium presents an immediate danger to the fish. Emptying the aquarium all the way will kill much of the beneficial bacteria in the aquarium and it will have to be cycled once again.
Live plants are also helpful in reducing nitrate levels and in consuming carbon dioxide that is expelled by the fish. An added benefit to plants is that they help provide a nice habitat for the fish in the aquarium.
Old Tank Syndrome
Over time a well-cycled tank can develop what is called "old Tank syndrome". As bacteria break down nitrogen compounds acid is produced.
Over time the concentrations of acid that is produced can become too high for many species of fish. Some hobbyists even take advantage of this when they are raising fish that like acidic water.
The problems associated with old tank syndrome can be reduced with regular partial water changes.
The Easy Way to Cycle an Aquarium
The easiest way to cycle an aquarium is to let nature do it for you. The key is to not let the amount of ammonia being produced in the aquarium outpace the bacteria that is growing in the tank.
Start by setting up the aquarium with live plants if they are desired (I highly recommend them) including the filtration system and the heater. Bacteria will grow best in warmer water in the high 70s° Fahrenheit. Raising the temperature too much will kill the beneficial bacteria as well as the plants.
After the tank has been set up with no fish in it for a few days put one or two small fish in the tank. The beneficial bacteria that is needed to start the cycling process will already be in the waste that the fish produce. Remember that there are very few beneficial bacteria in the aquarium at this point so it's important to resist the urge to add more fish.
Feed the fish sparingly for the next three months. During this time you may see signs of algae growing in the tank. Don't worry, though unsightly, the algae is a good sign that the tank is well on the way to being cycled.
After the tank is cycled you may add a fish or two more depending on the size of the tank. The key is to maintain a balance so that there is never more waste being produced than the bacteria can handle.
Testing Aquarium Water
In order to know that you have an aquarium with a well-performing nitrogen cycle, the water should be tested on a regular basis.
Test kits are reasonably priced and can test for ammonia, nitrites, and nitrates. Many experienced aquarists enjoy the liquid test kits however new hobbyists will likely find test strips to be easier to read.
The Dangers of Overfeeding
If you keep your fish in an office, avoid the temptation to feed your fish extra food for the weekend.
Healthy fish in a good environment will do much better with no food for two days than they will if you overfeed them.
Overfeeding can result in excessive waste, and any leftover food that remains in the tank will cause bacteria to multiply quickly. This may result in the water becoming unsuitable for your fish, and you might come into the office on Monday and find cloudy water and a dead fish.
5. Aquarium Lighting
Lighting is another challenge you may face when using a fishbowl. Improper lighting can result in high water temperatures or unsightly algae blooms. Here are some tips:
- Incandescent bulbs produce quite a bit of heat and can make it difficult to control the water temperature.
- Avoid putting your fishbowl directly in front of a window. Not only will it make it difficult to control the amount of light going into the bowl, but it can also cause fluctuating temperatures that make a poor environment for most tropical fish.
- There are very few lids with lights available ready-made for fishbowls. The most affordable option is to purchase a bowl that comes with a lid that already has a light. Preferably the lights should be LED. You should also place the bowl where it will get a small amount of outdoor lighting if possible.
- Remember that too much lighting will create algae issues. Algae is usually the result of an imbalance of lighting and nutrients.
6. The Benifits of Aquarium Plants
Plastic plants give your tank or bowl a better look and help give your fish places to hide and feel protected.
Live plants, on the other hand, have many more benefits, such as helping control the amount of ammonia in the water and providing small amounts of oxygen.
If you choose to use live plants, make sure to get good lighting for them. Too little light and your plants may wither and die. Too much light, however, will cause algae to grow and compete with the plants. It can even promote algae blooms which can cause your water to turn green (though Endler's actually don't mind algae blooms).
What do you feel the minimum size tank or bowl is for one or more goldfish?
Why Goldfish Shouldn’t Be Kept in a Bowl
Goldfish have long been considered one of the first choices for fishbowls. In reality, however, it is not a good environment for them. While goldfish will do well in an unheated tank and are quite hardy, they produce far too much waste for the bio-filtration process to handle in such a small space.
Goldfish grow fast and are soon much to be too big for most bowls. A full-grown Goldfish can grow longer than 12". Although the size of the tank can stunt the size of the goldfish, this is generally not due to the tank size, but rather it is a sign of ill health and of the poor water quality in the bowl.
So What Is the Minimum Size Tank for One or More Goldfish?
The number of Goldfish that may be kept in an aquarium can vary depending on the Goldfish variety, how long the tank has been set up, plants, the type and amount of filtration used and the frequency of partial water changes that are done.
As a general rule, a single common Goldfish should be kept in an aquarium that is at least 40 gallons. Add an additional 20 gallons for each additional Goldfish.
They may even be better suited to small ponds once they reach maturity.
The Challenges of Keeping a Betta in a Fish Bowl
Bettas, sometimes called Siamese fighting fish, are one of the most common tropical fish kept in bowls. Although they can survive in them, a bowl is not ideal for their health.
They get their nickname because males will fight to the death if they are left in a tank together. Females may also suffer the same fate if placed in a tank with a male betta.
Why Bowls Aren't Good for Bettas
Even though bettas are often seen in very small tanks or containers, they are poor homes for these beautiful fish. Small containers can quickly spike in ammonia and nitrite levels, which are toxic to the fish. In the wild, when bettas get trapped in small pools, they are assisted by tropical rains and natural vegetation which help reduce the number of toxins found in their water.
Temperature Problems When Keeping a Betta Fish
It is also difficult to maintain a stable temperature for bettas when they are kept in small containers. In the wild, the soil and mild climate of the tropics keep the fish at very stable temperatures both day and night. When kept in captivity, temperatures can change rapidly due to cooling and heating in a home or office.
If a betta is kept in optimal living conditions, it can live a life span of five to seven years and sometimes longer.
Recommended Habitat for a Betta Fish:
- 2.5-gallon minimum tank size
- Aquarium heater (least at 78° F)
- Places to hide, like plants, rocks, etc.
- Aquarium light
- Access to air, since bettas get oxygen from gulping air from the surface of the water
- A filtration system
Many bettas seem to enjoy small artificial single leaf decorations commonly known as betta hammocks or betta beds.
The betta bed is placed an inch or two below the surface of the water to give the fish a place to rest where it can watch for food and guard its territory.
Their Habitat in the Wild
Bettas come from tropical regions of Thailand, Vietnam, and Cambodia where they inhabit thickly vegetated marshes, slow-moving streams, rice paddies, and drainage ditches. These habitats often dry up to some degree in the dry season, leaving the fish temporarily in smaller pools and bodies of water.
Specialized Abilities of the Betta
Bettas have developed the ability to jump from pool to pool, enabling them to seek larger bodies of water and helping them survive during these drier periods. They also have what is known as a labyrinth organ. This specialized organ helps fish breath air from the surface of the water when water conditions become poorly oxygenated.
Although bettas can survive in these poor conditions, it is not ideal. Bettas prefer large pools or slow-moving rivers with lots of vegetation to hide in. Male bettas are believed to have a territory of at least three square feet in the wild.
A Betta Fish in a Well-Planted Fishbowl Alternative
Fish That Should Never Be Kept in a Fishbowl
There are some fish, no matter how skilled you might be in keeping fish, that should never be kept in a fishbowl. This list is by no means comprehensive but does cover some of the more common fish kept in aquariums today.
Aquarium Fish That Grow Big
Some fish can grow quite rapidly to a size that is simply too big for an aquarium. Here are a few of the more common fish found in pet shops that grow too large and too fast to be kept in a fishbowl.
- Angel Fish
- Clown Loach
- Common Plecostomus
- Tinfoil Barb
- Red Belly Pacu
- Freshwater Sharks
- Large Gourami
Fish That Produce an Excessive Amount of Waste
Fish that eat a lot of food usually produce a lot of waste as well. They don’t necessarily have to be large fish to produce a lot of waste.
Fish That Have Special Care Requirements
There are many types of fish that require special foods, temperatures or housing that make them poor choices for small tanks or fishbowls.
Fish That Are Aggressive
Fish that are aggressive shouldn’t be kept with other fish in small tanks or fishbowls. Small spaces with no places to hide and aggressive fish kept together is a disaster waiting to happen. Heres a few fish to watch out for.
- Puffer Fish
- Tiger Barbs
- Freshwater Sharks
- Betta Fish
- Chinese Algae Eaters
Little Turtles, Big Problems
Small water turtles such as red-eared sliders may seem like the perfect pet to keep in your fishbowl. However, these small turtles produce huge amounts of waste very quickly, producing a toxic environment for anything living in the bowl. Turtles should be avoided in aquariums unless there is ample aquarium size and filtration to accommodate the amount of waste the turtle will produce.
Even if you were to be able to keep the bowl clean and prevent problems caused by disease and microorganisms such as bacteria, these little turtles grow large very rapidly. They soon require a much larger home such as an outdoor pond.
A Health Concern for Humans
Water turtles are known to carry salmonella, which is potentially dangerous to humans, especially to those who are very young or very old. Even if your water turtle carries salmonella, it may not get sick from this very dangerous form of bacteria. It's a good practice to always wash your hands well with soap and water after handling turtles.
A Danger to the Environment
You may be surprised at how quickly little baby turtles grow up and how big they get. Often people that own water turtles find themselves in a situation where they can no longer care for them. Many of these people are tempted to release their turtles into local ponds or waterways.
However, releasing pet turtles into the wild not only exposes wild animals to dangers such as disease and predation, but it is also illegal in most states.
Please consider the long-term consequences of owning one of these cute little guys.
Some Good Choices for Your Bowl
The following is a list of some possible fishbowl pets and how you can keep them healthy.
1. Paradise Fish: An Alternative to Bettas
If you want a fish similar to a betta for your fishbowl, the paradise fish may be a good alternative.
This fish (macropodus opercularis) is a species of gourami and a close relative of the betta. Male paradise fish can change their coloration as they defend their territory from other males or court females. When these displays occur, the males will often display their finnage in a similar manner as the betta.
Habitat and Food Details
Paradise fish can tolerate a wide range of water conditions. Compared to the betta, they also come from cooler climates, so they can tolerate unheated fishbowls much better than them.
This kind of fish is easy to care for and will accept just about any type of fish food. For best health, they should be served high-protein food.
Guppies are one of the easiest tropical fish available for beginner hobbyists. These beautiful fish come in some amazing color varieties and are quite hardy.
Behavior and Habitat
For best results in a fishbowl, the wild-type feeder guppies are a good choice. These guppies should do well in smaller bowls, adapting to the small living quarters and changing temperatures.
Guppies are a schooling fish and should be kept in small groups. If you don't want any baby fish (fry), you may wish to keep a small group of 3–5 males depending on the size of the bowl.
If you wish to breed the guppies, it is helpful to have trios as small as one male and two females. Too few females will result in the females being over courted by the males.
Guppies are not recommended for a fishbowl if you are breeding them. Uncontrolled breeding can quickly lead to overcrowding, leaving them susceptible to disease and sickness.
Recommended Requirements for Your Guppy Habitat
- 5-gallon tank (ideal minimum size)
- Aquarium heater to keep the temperature between 72° and 83° F
- Aquarium light and hood (provides lighting for viewing the fish and prevents them from jumping out of the tank)
- A filtration system of appropriate size, depending on the number of fish and size of the tank
3. Endler's Livebearers
Closely related to the guppy, many of the pure Endler's livebearer strains are thought to be extinct in the wild.
These little guys are prolific breeders and have a "wild" and active behavior. Be sure to purchase your Endlers from a reputable dealer if you wish to get pure N Class Endlers.
If you want a fish that is unique, active, and easy to care for, this might be just what you're looking for.
First discovered in Venezuela by Franklyn F. Bond in 1937, most varieties of this fish have somewhat metallic colors. It was the bright green metallic color of the fish that first caught the attention of Dr. John Endler in 1975, the person that they were named after when they were rediscovered.
Care should be taken if you wish to have pure strain Endler's livebearers because they will readily crossbreed with guppies.
Caring for Endlers Livebearers
Care for Endlers is very similar to guppies. These fish are very active and enjoy schooling in small groups.
Unfortunately, Endler's prefer warmer temperatures than many other small fish, making them a poor choice for unheated fishbowls. Temperatures below 60° Fahrenheit will kill them.
Recommended Minimum Requirements for Endlers
- 5-gallon tank (minimum)
- Aquarium heater (keep the temperature between 72° and 83°)
- Aquarium light & hood (provides lighting for viewing and prevents fish from jumping out of the tank)
- A filtration system of appropriate size. Endlers prefer ponds and pools in the wild with little water movement. The filter should be based on the number of fish and size of the fish tank and not be too fast-moving for the fish
4. Zebra Danios
If you're looking for a small, active fish that is easy to take care of, the Zebra Danio is a good choice. They will do quite well in a larger fishbowl even without a heater.
Minimum Requirements for Danio Care
- The minimum tank size depends on the variety of Danio, however, small varieties can thrive in tanks as small as 2.5 gallons with appropriate filtration
- A heater is not required, though it is recommended to eliminate fluctuations in water temperature
- You'll need an appropriate filtration system depending on the number and variety of Danio
- Tank lighting
They will do quite well in a larger fishbowl even without a heater.
5. White Cloud Minnows
The White Cloud minnow comes from the streams of the White Cloud Mountains in Southern China.
Once believed to be extinct in the wild, this tiny fish has been rediscovered both in China and Vietnam. Still quite rare in the wild, the White Cloud is considered an endangered species.
This active little fish may be one of the best choices for small tanks because it does best in unheated tanks at temperatures between 64°-72° F and is quite hardy.
Recommended Minimum Requirements
- 10-gallon tank (does best in large schools)
- Plants and places to hide as well as open spaces to swim
- Appropriate filtration system
- Subdued lighting for best color
6. Other Good Choices
There are many other varieties of fish that could be good candidates for smaller tanks such as some types of tetras, platies, pygmy cories, and killies as well as African Dwarf Frogs and some types of shrimp.
A Well-Planned and Maintained Aquarium
Proper planning prior to buying fish or a tank is one of the first steps to having an easy-to-maintain aquarium with fish that are happy and healthy.
If you've had trouble keeping fish in the past, don't be afraid to try again. Study everything you can about the type or types of fish you are considering purchasing and get the appropriate equipment to help them thrive.
With proper preparation, you may find it's much easier to keep fish than you thought.
More Articles About Keeping Fish in Aquariums
How to Set up a Fish Tank: A Beginner's Guide
Setting up a fish tank properly makes it much easier to keep fish.
Can Guppies Have Babies Without a Male?
Many aquarists have owned a female guppy without a male and the female has babies. How does this happen?
Best Aquarium Filters for 10-Gallon Fish Tanks
There are many great aquarium filters on the market today. Which one is best for a 10-gallon aquarium and do you really need one?
How to Buy Freshwater Aquarium Fish (With Community Tank Ideas)
Thinking about setting up an aquarium? Here are some tips when considering your fish purchase.
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
Questions & Answers
What would the best fish be for a bowl with a few plants in it?
While I wouldn’t recommend a bowl as they are simply too small, if I were to keep a fish in a bowl and I didn’t use a bowl heater I would lean towards a Paradise Fish and as many live plants as possible. They are a nice alternative to a Betta as they do well at room temperature.
If you could get a small aquarium I would lean towards three White Cloud Mountain Minnows with lots of plants. The are super easy to breed and it’s great fun to find baby fish (fry) swimming in the tank every once and a while.Helpful 22
Why should I keep only one fish in a fish bowl?
I would not recommend keeping any fish in a fish bowl however the number of fish that may be kept in any size tank depends on the bio-load the fish create. The more a fish eats the more bio-load is placed on the tank and the more bacteria is needed to consume the waste.
Some fish such as goldfish can produce large amounts of waste and can grow quite rapidly making them poor choices for all but large aquariums or ponds. Smaller fish such as male Endlers produce very little waste so it is possible to keep more fish in a smaller space.Helpful 8
Does my betta fish need a plant in its tank?
He will do just fine for a while, however, live plants help to improve the Bettas overall living conditions.
Live plants help to provide cover and help to reduce stress on the fish.
Plants also help improve water quality for the fish.Helpful 19
Can fish live in a bowl?
Yes, many fish can live just fine in a fish bowl when kept in the proper conditions however it's usually not an ideal situation for the fish.Helpful 13
Can shrimp live without plants?
While shrimp can be kept without plants, it can be more difficult to maintain proper water quality.
I would recommend trying to maintain the best environment possible to keep the shrimp as healthy as possible.Helpful 10
© 2014 Marty Andersen