Freshwater Fish

You’ve heard of fish tanks, right? Those big glass and plastic boxes that fill up your living room with bubbling water and colorful underwater scenery, and sometimes include a cute little glass tunnel that you can walk through, feeling like you’re under the sea?

Well, what you may not have heard are that fish tanks that can be enjoyed by the whole family.  Yes, you read that right: these new-fangled water boxes are no longer limited to just fish and aquatic plant life.  No, now you can have full-on fish tanks with fish, but also (gasp!) your very own pet!

Even though they aren’t as popular as dogs, cats, and other household pets, there are many reasons to consider a freshwater fish as the newest member of your family. If you’re still on the fence about whether or not you can handle the responsibilities of owning a freshwater fish, let these reasons persuade you:

  • Fish don’t require much time!
  • Maintaining a fish tank is easier than you think!
  • Once the tank is set up they don’t cost much to maintain!
a large number of different freshwater fish swimming in an aquarium
a close up of an angelfish


The Angelfish is a great fish to have in an aquarium for several reasons. For one, it is easy to maintain and to breed. It requires very little space, and the water conditions don’t have to be completely perfect. It is a hardy fish, so it can handle a few mistakes in the maintenance. 

The Angelfish is active, and it will swim around your aquarium all day. This is a great fish for a beginner, because it is not picky about what it eats. It can be fed flakes or frozen food. If you want to get more fancy, you can try feeding it brine shrimp, and it will eat right out of your hand.

There are more than 30 species of angelfish. Most of them are tropical fish that live in saltwater but a few live in freshwater. Angelfish are named for their round, flat, fluffy pout, which resembles a human angel’s face. They have prominent dorsal and pectoral fins and a long flowing tail. Their bodies are covered with tiny scales. 

The colors of angelfish vary widely, but they are often shades of blue, orange, pink, red, or yellow. Angelfish are generally active swimmers. They are social fish that swim in schools.

Neon Tetras

Neon Tetras are a group of schooling fish that originates from the rain forests, rivers, and streams of tropical and subtropical Africa and South America. They are a small fish that can live up to several years in captivity. Neon Tetras sport iridescent blue colors and are named appropriately. 

This species requires soft and slightly acidic warm water in the tank. They eat typical aquarium food that is on the smaller side, to accommodate the small mouths of these fish. Tetras in general are a good community fish that enjoy living in groups of six or more. They will mix well with other fish of small and medium size. The mild behavior of this fish and their easy to care for requirements make Neon Tetras ideal for beginner and expert hobbyists alike.

a beautiful neon tetra swimming down from the surface


Zebra Fish (also called zebra danio) have become a favorite fish among hobbyists of all levels. They originate from the streams of the India and Pakistan areas. Due to modern breeding methods, this fish can survive in fresh water of almost any temperature. Your Zebra Fish will not require a heater for their tank, but they do enjoy water that has a gentle current. A large tank is recommended for these playful and curious fish, as they spend their time swimming rapidly around their habitat.

Zebra Fish are small, normally attaining a size from two to two and a half inches.

Most will live two to three years and with proper care, some may live to be four or five years old. Zebra Fish are a schooling fish that thrive in schools of five or six and these numbers will keep aggressive behavior to a minimum. This fish will make a welcome addition to your tank and will get along with communities of other small fish.

Freshwater Shrimp

The freshwater shrimp is the Rockstar of the aquarium pet world. The small crustacean brings color, adventure, and a sense of wonder to any tank, whether it’s a plexiglass cube in your bedroom, or an epic series of custom aquariums in your basement.

Freshwater shrimp are beloved for their ability to eat leftover food and algae, which makes them a great addition to tanks with messy eaters. Their small size makes them an excellent snack for larger fish, and they make an excellent addition to the diet of breeding fish such as koi and betta. 

Some species of shrimp are also great at keeping the tank clean, such as the ghost shrimp, who naturally consume decaying plant matter. If you are looking for a natural way to keep your tank clean, a few freshwater shrimp may be what you need!

a red and white freshwater shrimp looking for food


Guppies are the world’s #1 fish recommended for beginners. They are economical to purchase and own, and are happy to breed right in the tank. Robert John Lechmere Guppy, a geologist and researcher, is credited with first discovering the fish in Trinidad in 1866 and, hence, the fish gets its name from him. This fish is also known as Millions Fish, due to the ease with which they will propagate, and Rainbow Fish from the broad range of colors they display. All Guppies have colorful tails, with some being fan shaped.

Many Guppies will happily inhabit a tank, requiring only one gallon of water per fish. This fish is quite active and has a varied diet. As omnivores, they will eat anything you give them. If you do decide to breed your Guppies, a separate tank or enclosure is needed for the babies, as the adults are known to eat their young. Considered to be low maintenance, Guppies require only a suitably large tank, a good filtration system, adequate food, and warm water. This fish will provide endless hours of relaxation to the new hobbyist. Guppies in captivity will live from one to five years with adequate care.


Rainbowfish are a family of freshwater fish that originate from Australia, New Guinea, Indonesia and Madagascar. More than fifty species are family members, with some being more common than others being kept as pets. Their coloring is what gives them their name; typically being iridescent shades of silver, blue and yellow. As with most fish, their coloring deepens with age and brightens with stress.

In the tank, it is advised to have no more than one male Rainbowfish, with up to five others of the group being female. This would limit aggressive male tendencies that could cause injury. This is a good community fish as it does generally get along with other species. With normal day to day activities, Rainbowfish tend to be peaceful and require low levels of maintenance. They do appreciate artificial plants and rocks that can be cleaned in their habitat for hiding. With this fish, a clean environment is very important, so consider changing the water on a regular basis to provide the best environment.



Goldfish are an extremely popular type of fish to keep as pets. Although many hobbyists have successfully raised Goldfish, some myths about this fancy fish are persistent. For instance, it is commonly believed that Goldfish live about five years. Actually, if cared for properly, a Goldfish can live to twenty years old. Another myth that must be dispelled is that a Goldfish will grow to fit the size of its bowl. This is also not true and, in fact, Goldfish need more than a bowl as their enclosure. They prefer large tanks that mimic the ponds of their ancestors.

A large tank or aquarium can be a lifetime home for your Goldfish, as some varieties can grow to be adults of one to two feet in length. These fish require a powerful filtration system, as they tend to create a lot of dirt as they go about their business. A large tank also ensures stable water temperature, which is preferable for this type of fish. Careful attention to their diet must be paid, feeding once or twice a day. Goldfish do enjoy a community atmosphere, but like us, do not like to live in crowded spaces. 

an orange goldifsh swimming through some bubbles in an aquarium
Cherry Barb

Cherry Barbs

The Cherry Barb is an extremely popular tropical freshwater schooling fish that can be found in the tanks of many hobbyists. They originate from Sri Lanka and are readily available in North America. This is an attractive fish that gets its name from the reddish colouring that darkens when approaching breeding time. They like to live in communities of at least five, with females outnumbering males being the healthiest ratio. Cherry Barbs will get along with most other calm varieties.

Care for these fish is considered to be low maintenance, so they are suitable for beginner hobbyists. The tank should be well planted with adequate space left for swimming. Slightly acidic water conditions are the preference of these fish. As omnivores, Cherry Barbs will eat all kinds of live, fresh or flaked foods, preferring to be fed daily.

Betta Fish

Betta is a tropical fish species that is also known as Siamese fighting fish. While beautiful to look at, these fish require specific care to keep them healthy and thriving. They originated from Southeast Asia, are reported to have been domesticated as early as the 18th century, and were first introduced into the US in 1910. This fish has come to be a favorite pet in many family homes.

Betta fish require a large tank that has a low-flow filter system, contains very warm dechlorinated water, and has just the right amount of soft decorative items for hiding in and swimming around. While these fish are territorial by nature, they do get bored unless they are housed with other sea life for interactions. In the wild, they eat insects and insect larvae. In your care, they will enjoy a balanced carnivore’s diet of pelleted or flaked food on a daily basis. An intermediate to advanced hobbyist can expect to enjoy keeping these fish happy and healthy for three to five years.

two multi color betta fish swimming together
a cory catfish swimming

Cory Catfish

When people think of Cory Catfish, they think of an algae eater, but what you might not know is that Cory Catfish are also known for their beautiful colors.  Not only do they come in a variety of vibrant colors, but they also have a variety of patterns.  These patterns tend to be thicker on the flanks and thinner on the head.

Cory Catfish are a species that’s native to South American wetlands. They are small fish, and they’re one of the most popular catfish species on the market today. Cory Catfish are a very active species of catfish. They are also known to be quite friendly towards other fish. 

One of the best things about catfish is that they can get along with most tank mates. They’re particularly nice with other species of fish, and they won’t hurt smaller fish either.

Freshwater Crabs

In freshwater crabs, you’ll discover the perfect pet for your home. While they may not be as popular as dogs and cats, freshwater crabs are just as fun and easy to take care of, and can provide years of enjoyment.

There are a number of different types of crabs available in the United States, and they all have different sizes, shapes, colors, and activity levels. There is a type for every family.  These pets are ideal for kids, and parents will love that they only need to be fed once a day, and that they can clean up after themselves.

Freshwater crabs are a great addition to any aquarium! They are almost completely harmless to other tank mates, and are not too aggressive with other crabs. They are also a great way to introduce children to the world of pet ownership, as they can handle most food without the need of additional prep work. They are also quite easy to care for, and most of their needs can be met with a minimum amount of effort.

What they lack in looks they make up for in personality.  Freshwater crabs are active little creatures that will scuttle around the floor of your tank, looking for things to scavenge. This is usually food that others in the tank didn’t eat. A freshwater crab is just one of the many unique animals that make a great addition to your family.

fiddler crab


Plecostomus (commonly known as a pleco) are great fish for your family’s aquarium for many reasons. First, they are easy to take care of. They are not picky and the only thing they require is a lot of water to swim in. They can save you money by not needing an expensive filter. The Plecostomus does not need a fancy filter because they are the filter eating up everything at the bottom of your aquarium. Third, they are very low maintenance.

They are not very active and will spend most of their time hanging out at the bottom of the tank. They have a pleasant disposition. For the most part, they are not as aggressive as other types of fish and they do not nip at other fish.

A Plecostomus isn’t a fish that many think about when you’re looking to add a new member to your aquarium. But they really should be because they are a great fish for even the most experienced aquarium owner.

Plecostomus are a species of sucker fish native to South America, and they are like a vacuum at the bottom of your aquarium. They do a lot to keep your aquarium clean and keep all the bad waste chemicals to a minimum between water changes. They do a lot to help keep the overall health of the other fish high.


Oscars are one of the most popular species of fish for freshwater aquariums. They are often included in larger starter aquariums, and are known for being quite active. They are a type of cichlid fish, originating from South America. They are known to be aggressive with each other and other fish species.

Because of their aggressive nature the Oscar is usually the first fish for the aquarium. We suggest that you pick its tank mates carefully to avoid having your entire aquarium eaten by the Oscar. This is why it’s generally a bad idea to introduce this fish to an existing aquarium as an afterthought.

They are nocturnal, which means they spend the day sleeping in a sheltered spot, and come out at night to hunt for food. For a family aquarium this could be a bit of a problem, but generally they will be alerted at feeding time by the splashing and movement of other fish in the tank

Even after all of the warnings, many families cannot resist buying an Oscar because their coloring makes them a very attractive addition to almost any tank.

Freshwater Fish General Information

Goldfish are a common example of freshwater fish. They are the most popular species and can be found the most often in North American homes. In fact, they are just one of hundreds of different types of freshwater fish in the world. Many species are suitable to be kept as pets in fish bowls and aquariums at home or at work.

Freshwater fish make great pets and are suitable for first-time owners and experienced hobbyists alike. Note that care must be taken to ensure that all of the residents of your fishbowl or aquarium get along together. As with any pet, freshwater fish require a time and energy commitment to attend to their care. Some types of freshwater fish will be appropriate for beginners and others are better suited to pet owners with more experience. If you are considering keeping freshwater fish as pets, it is important to understand their relative costs and care requirements.

Some things to consider are:

  • The size and number of fish, as this informs the size and of the fishbowl or aquarium required
  • How much attention is required to attend to the particular needs of the chosen varieties
  • The amount of equipment required, e.g., aquarium/fishbowl, optional water pumps/aerators, decorations, places to hide, and fish food
  • The cost to purchase the fish and required supplies
  • Care and feeding requirements — feeding and cleaning schedule
  • Activity level and compatibility with the owner’s/family’s activities
  • Lifespan – some types of fish live longer than others
Comparison between Different Freshwater Fish Species

The thought of buying a pet fish is not only exciting but can also be daunting. There are so many freshwater fish species that make great pets.

When buying a pet fish, you should think about how large it will be as an adult because some remain small at adult age while others can become much larger. The size of the fish determines the size of the aquarium you will need. 

You should also look for a fish that requires low maintenance, especially if you’re a beginner. Maintenance entails feeding, cleaning, and susceptibility to illnesses.

It’s also very important to select fish types that don’t mind living with other fish. Some fish are aggressive and prefer living alone, while others love living in groups.

The Most Popular Freshwater Fish
Freshwater fish Size Characteristic Cost Lifespan
GoldFish 2 – 6 inches Social and loves living in groups. The fish is intelligent and easily gets used to its owner. $1 – $5 10 – 30 years
Betta 2.25 inches Aggressive towards other fish types $4 – $10 2 – 3 years
Neon Tetra 1.5 – 2.5 inches Easy to keep and can live in a group with other species of fish $1 – $2 5 – 10 years
Rainbowfish 6 inches Very peaceful fish with vibrant colors. However, the fish requires extra care to show the colors. $2 – $10 5 years
Zebra Danios 1.5 – 2.5 inches Very active fish that adjusts to any water temperature. Can live as a group of not more than 5 zebra Danios in a tank. $1 – $5 5 – 7 years
Guppies 0.6 – 2.4 inches Compatible even with other fish species and is very peaceful. $2 – $8 2 years
Cherry Barb 2 inches Peaceful fish that often occupies the corner of the aquarium. The fish can live together with a tetra in the same tank. $1 – $6 5 – 7 years
Cost of Owning Freshwater Fish

Other than buying a fish, the total cost of keeping a pet fish depends on the equipment required to set up an aquarium. There are additional miscellaneous costs, and food.  Most people don’t factor in veterinary charges because the cost of a vet visit is often many times greater than the cost of the fish.

Fish is a low maintenance pet compared to other pets, which is why most people prefer having pet fish in their homes.

Here is a table detailing some of the costs you might incur before and after bringing home a finned friend.

Item Cost
Fish $1 – $10
Gravel /decorations $1 – $30
Aquarium 10 gallon aquarium $10 – $30

30 – 50 gallon aquarium $350 – $580

Aquarium heater $15 – $30
Filters & Air Pumps $70 – $100
Lighting $5 – $30
Feeding $10 – $100 annually
Veterinary charges For most fish, zero
Water test kits $50


The initial cost of owning a fish is not terribly expensive and there are many species to choose from in your local pet store. Notably, some exotic fish species can cost more than $100, however these fish are not as common in a family fish tank.

Lighting and heating options for an aquarium are optional because most fish can do without them. However, depending on the specific pet fish you have, you need to adjust temperatures to their particular need. While the fish do not require lighting to survive the light makes the aquarium beautiful for your enjoyment.

If your home has temperatures of about 74 degrees Fahrenheit, then you don’t have to install heating features on the aquarium for many types of fish.

The gravel, stones, and other decorations often depend on the fish type, the size of the tank, and your taste of decorations. Therefore, you can expect the cost of decorations to vary from person to person.

What is the Ideal Habitat for a Freshwater fish?

Materials used

Before buying an aquarium, you should first select the type of fish you want to put inside. Aquariums are made of either acrylic or glass. The glass aquariums are more common because they are cheaper.  Aquariums made from acrylic are generally higher end for tanks larger than 30 gallons.  Because of the price and size we will not cover them in this article.

Glass aquariums are less expensive, easy to clean and are also scratch resistant. Most families will choose this option because of price, but also because it will be big enough for the fish they select.

Size and shape

When buying a fish tank, the rule of thumb is always having a gallon of water for every fish inch. Larger tanks are better than small ones because it gives fish enough space to swim. A larger tank also allows you to make mistakes without affecting your pets.

As you choose the aquarium, select one with a more extended surface area for proper oxygen circulation. A nice long rectangular fish tank lets your fish move around and lets the water and oxygen circulate easily.

Tank Substrate

A fish substrate is often composed of gravel, sand, and a variety of stones. Even though the substrate is optional, it adds aesthetic value to the aquarium. Substrates come in all forms of colors and shapes. It’s advisable to take time and identify a substrate that matches the theme and colors of your aquarium.

Other than the aesthetic value, substrates also act as a medium where healthy bacteria can live and break down nitrogen to release oxygen for the fish. Also, the substrate serves as a place where live plants can grow and provide oxygen for the fish.

Some freshwater fish also love burrowing at the bottom of the aquarium for safety. By having a material that the fish prefer, you provide them an extra sense of security.  Sand is the best type of substrate for fish that love burrowing.

If you have many fish pets in one aquarium, the lack of a substrate at the bottom could lead to a reflection of the fish at the bottom. Some fish types could get frightened by the reflected images.  Gravel is cheap and very common as it provides a more natural bottom to the tank.

The substrate also acts as a laying ground for your fish. The gravel hides the eggs to prevent other fish in the aquarium from eating them until they hatch.  This is really only important if you are interested in having the fish breed.

If you decide to use a gravel substrate, and you want live aquatic plants, then you will want between one and a half to two inches. This gives the plant roots room to take hold otherwise they may not have enough space for the roots.  However, if you decide to use sand or go without live plants then the substrate only needs to be between one and one and a half inches.

What is the best Aquarium Size?

Unlike most saltwater pet fish species, freshwater ones are hardy and don’t need big fish tanks. Here is a table showing some of the most common freshwater pet fish and the recommended aquarium size.

Fish Aquarium size
Goldfish 20 gallons
Zebra Danios 5 – 20 gallons
Betta Fish 2.5 – 5 gallons
Neon Tetra 5 – 15 gallons
Guppies 5 – 10 gallons
Rainbow Fish 30 – 55 gallons depending on subspecies


The bigger the tank size, the better for your pet because they get enough space to swim. It’s also easier to manage oxygen absorption in a bigger tank as opposed to a smaller one. If you plan on having more than one fish type in the aquarium, then a bigger tank is extremely important.

Food Preference of Freshwater Fish

Some fish eat plants, others eat meat, while some can eat both. It’s also worth noting that some fish eat from the surface, others in the middle, and some at the bottom. One of the ways to determine where your fish feeds from is the shape of their mouths.

Young fish should feed on more proteins for fast growth and fewer carbohydrates. On the other hand, adult fish have lower metabolism levels and should feed on more carbs and fewer proteins.

Overfeeding your fish is a problem because the uneaten food ends up collecting in the substrate as waste. The waste will decompose and deteriorate the quality of water in the fish tank.  The more of this decaying matter that builds up, the faster the water quality will drop.

Adult fish should feed once a day at the same time. Younger fish are more active and may require feeding roughly three times a day. Fish that feed on vegetables also tend to eat throughout the day because of their small stomachs. Therefore, you can place bits of algae or other plants in the tank for them to nibble whenever they want.

You can get different food types for your fish from pet stores. For example, flakes exist in different shapes, colors, and sizes. Different pet fishes can detect food using smell or even color.

You should also supplement the flakes with frozen or live food for your freshwater fish for proper nutrition and overall health.  You will notice the fish that eat meat will be much more active during feeding if you give them frozen or life food.

Some of the best frozen foods include brine shrimp. However, you can also find some live brine shrimp for your pet. Some of the safest live foods also include earthworms, water fleas, mosquito larva, and wingless fruit flies.

Herbivore fish species like the Mollies enjoy fresh vegetables like spinach, dried algae, or frozen kelp. Fish, just like people, enjoy some variety in their diets.  You will keep them more healthy by feeding them different foods from day to day.   There are many varieties to choose from with a quick search in the pet stores.

Aggressiveness in Freshwater Fish

Although rare, some fish species can become aggressive, especially if living as a group. Experts insist that fish only become aggressive if it’s trying to protect its offspring or territory. Sometimes aggressive behaviors can lead to the death of other fish.

In a small aquarium the fish may not feel like there is enough space and you may see some fish chasing other fish around.  This may become common during feeding times if they feel that there is not enough room for them to feed together.  However, with a big tank, rarely will fish portray this aggressive behavior.

Here are some signs of aggressive behavior in fish.

          Flaring of fins



General Freshwater Fish Care

To support aquatic life, the water in the aquarium requires balancing of several different things. It’s advisable to use a dechlorinating agent coupled with an aquarium supplement to achieve the best conditions.

Testing of the PH levels in the water should be done at least once a week using the testing kits. The ideal PH for freshwater fish lies between 6.8 and 7.5, depending on the specific fish you have.

The temperatures of the aquarium should also be maintained at 72 °F – 82 °F. Also ensure that the fish tank is placed far from direct sunlight common near windows or near vents. Vents circulate air, which could alter temperatures in the tank. A drastic change in water temperatures could easily kill your fish. The good news is that you can also regulate temperatures in the aquarium using an aquarium heater.

Replacement of water in the aquarium should take place once a month. Changing the water once a month ensures that nitrate levels in the water don’t accumulate to toxic levels. When replacing the water, only change about 25 percent of the total amount of water in the tank.

If you feed your fish algae, you can also expect a buildup of the algae at the bottom or on the sides of the aquarium. Water with algae appears murky, and the glass becomes cloudy.

You can use an algae magnet or a brush to clean out the algae from the aquarium glass. You can also clean the substrate of any algae utilizing a vacuum cleaner that can filter out the debris leaving your gravel intact.

The filtration system of the fish tank should also be well maintained to avoid contaminating the fish tank. A total rinse out of the filters is recommended every 6 months to ensure that they continue to function correctly.

In a nutshell, having an aquarium in the home often reduces stress and helps people to relax. Aquariums also add to the aesthetic look of a home. They are a fairly low maintenance way to beautify your home and give you something to watch other than television.

Basic Facts about Freshwater Fish

There are about 10,000 freshwater fish species in the world and about 800 species in North America alone.

Pet fish are also intelligent and can remember things, regardless of what the myths may tell you. For example, the goldfish often rub against other fish in the tank as a sign of showing affection.

Fish species also communicate with each other through low-frequency sounds. Experts also say that fish are known to cooperate and live harmoniously in groups.

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