Choosing Your Freshwater Fish

Originally posted on Bob’s Tropical Fish –

Choosing Your Fish

There are thousands of freshwater species that could potentially make good home aquarium residents, and hundreds of these species are commonly kept by hobbyists. So how can you choose the right fish for your tank?

First you can learn which species are only recommended for experienced fishkeepers (and some not for any home aquariums at all) and which are recommended for beginner hobbyists. Then, you can narrow down your choices even further by learning about different species of commonly kept fish and their care requirements, so you can decide which fish are the right fish for you.

Some fish are easier to keep than others, and these fish make especially great pets for first-time freshwater aquarium keepers. This section of our site will cover some of the most popular fresh water fish. African Cichlids, our favorite freshwater fish, are covered in another section.

Good starter fish include:

Neon Tetras

Neons generally do best when kept in a species tank rather than a community tank. They are schooling fish, usually forming groups of six of more. They have an iridescent sheen to their scales and will actually seem to glow if the tank is lit properly. Other related species will generally also make good first-tank residents, such as the Cardinal Tetra, the Glowlight Tetra, and the Black Neon Tetra.


Swordtails grow to be about four inches long, making them good residents for just about any freshwater aquarium. In an aquarium environment, swordtails are generally peaceful, but male swordtails may be aggressive toward each other. Swordtails will breed quite easily and quite prolifically, but female swordtails are well known for eating their young so they must be removed to allow the young to survive. These active fish will feed on a variety of prepared foods and live foods.


These broad-bodied fish are close relatives of swordtails. Domestic platies come in a wide variety of colors and are fairly easy to breed, as long as they are given enough plants to provide some privacy. Platies are schooling fish, and they generally thrive in small groups of about five fish. They will do well in most community tanks, and a group will also make a beautiful single-species tank.

More About Freshwater Fish

There are so many choices of freshwater fish, it helps to understand more about the various varieties including livebearers, small schooling fish, bottom dwellers and those not recommended for the home aquarium.


Livebearers are members of the group called cyprinodonts. There are many species of livebearing fish (fish that give birth to live young rather than laying eggs), but in the fishkeeping hobby, the term “livebearer” usually refers to guppies, mollies, platies and swordtails.


In the past, guppies were extremely popular fish among beginner hobbyists. They are still commonly kept today, but more often by experienced hobbyists. Guppies are an especially popular fish to breed, particularly fancy guppies.


Although mollies are widely available from pet stores and other sources, they are not a good choice for novice aquarists (see Not Recommended).


Platies are highly recommended as a great fish for the first-time hobbyist. They are widely available, hardy, peaceful fish that come in a great variety of color combinations. Most wild platies are silver, blue, or orange, while domesticated platies can be white, yellow, gold, orange, red, blue, or black. In a community tank, platies will school. A smaller tank can hold up to eight pairs of platies, while a larger tank could house up to 15 pairs!


Cousins of platies, swordtails make great aquarium residents. Their name comes from the sword-like extension the males have on their tail fins, which they use to attract females and to intimidate other males. Wild swordtails are generally green with iridescent or black markings, while domesticated swordtails are available in a wide variety of colors. Swordtails are larger than platies and the males can be quite aggressive, so keep them in a fairly large tank, and keep only one male with several females.

Small Schooling Fish


The tetras most commonly found in the fishkeeping hobby are generally small, peaceful, beautiful fish. They are schooling fish and do so to protect their livelihood. Tetras tend to be skittish and always on the lookout for predators, so schooling provides them with the comfort and security they need. A tetra that is not part of a school can stress itself to the point of sickness or even death. Some of the tetras most suitable for a beginner tank are neon tetras, cardinal tetras, black neon tetras, lemon tetras, and bleeding heart tetras.


Danios, members of the cyprinid group of fishes, are fairly similar to tetras. Their hardiness and adaptability make them a good choice for beginner aquarists. One notable characteristic of danios is their uniqueness of appearance within the species. Patterning can be quite different between two danios of the same species, making it relatively easy to identify individuals within a group.


Platies are available in a wide range of colors. They are broad-bodied fish and fairly easy to breed, as long as their tank contains enough plants to provide some privacy. Platies generally thrive in small groups of about five fish. They will do well in most community tanks, and a group of platies will also create a beautiful single-species tank.

Bottom Dwellers


Loaches spend most of their time on the bottom (whether in the wild or in your tank), exploring their environment and looking for food. They come in a variety of colors and also have a wide range of behavior patterns, with some loaches being extremely peaceful and others more aggressive. The loaches most commonly found in the hobby today are naturally found in China, India, Thailand, and a few other places. Loaches are fairly easy to keep as long as they are provided with a smooth substrate (to avoid damage to their tender underbelly) and a few places to hide and rest during the day.


There are more than 2,000 species of catfish, hundreds of which are available in the fishkeeping hobby. Some catfish make great community fishes, while others are better kept alone or in a planted tank. Most catfish will spend the daylight hours in hiding. Likely the only way you will be able to see your catfish on a daily basis is if you plan the feeding time in the evening, after the lights are out, when your catfish will feel most comfortable being exposed.

Plecos make up the largest group of catfish, which is the family Loricariidae. This family includes more than 450 species. Plecos are found naturally throughout most of South America and some of Central America. Additionally, they have managed to establish themselves in the waters of Florida, Hawaii, Australia, and several other locations with water parameters that are very similar to those that these fish naturally habitate. They can range in size from several inches to several feet, with some of the smaller varieties making great pets for first-time fishkeepers.

Freshwater Fish Fish Types Not Recommended

There are some fish that new hobbyists should avoid. The reasons vary, but there are certain species that are just not suitable residents for the community tank of an inexperienced fishkeeper.

Chinese Algae Eaters

These fish (often referred to simply as “algae eaters”) are a very poor choice for any hobbyist, experienced or not. They are not particularly efficient algae eaters, and they tend to mature into nasty, territorial adults that often do not survive for very long, as they are prone to self-inflicted starvation.


For many years, goldfish have been popular pets for beginner fish hobbyists particularly for children. While goldfish are beautiful, intriguing fish, they do not belong in an average tropical tank setup. Goldfish grow to a relatively large size, and they produce too much waste to thrive in a regular tank situation.

Male Bettas

Bettas, also called Siamese fighting fish, do not belong in a freshwater community tank. If you wish to keep one of these beautiful creatures, you will need to provide a separate aquarium just for them.


Mollies are often recommended as good beginner fish, but their sensitivity to water conditions makes them difficult to keep, and therefore, mollies should be reserved for more experienced hobbyists.


Other than cory or bristlenose catfish, these fish are poor choices for a home aquarium. Although they start out small, catfish can grow to be very large, anywhere from one to fifteen feet long. To keep any catfish species (other than the two exceptions) would require a large and complex setup, much more than the average new hobbyist is able to provide.


While there are several freshwater shark species, none of them are suitable for housing in a home aquarium. There are also several fish that have physical characteristics that give them a look similar to that of a shark and are often referred to as “sharks,” but they are not technically sharks, such as the red-tailed black shark and the rainbow shark. These fish are a poor choice for a novice aquarist, but if you decide to give them a try, keep only one specimen at a time. Multiple “shark” species generally will not get along well together.


As with sharks, there are some fish that are referred to as “eels” that technically are not eels. These fish are not recommended for beginner hobbyists. They tend to be difficult to keep healthy, and they are infamous escape artists. Many of these “eels” also grow to a large adult size that is not suitable for the average tank.

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