15 Cheap Freshwater Aquarium Fish to Buy on a Budget

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Written by Jorelle Baker

Published: December 1, 2023

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Key Points

  • On average, freshwater fish are easier and cheaper to buy than saltwater fish because they require less chemical balance with salinity.
  • Similar-sized freshwater fish should be kept together to avoid aggressive behavior or predation.
  • Families should purchase goldfish, tetras, platys, danios, and mollies together for a colorful assortment of aquatic life in their tank.
Small fish tank aquarium with colourful snails and fish at home on wooden table. Fishbowl with freshwater animals in the room

As a general rule of thumb, 1 inch of fish should live in 1 gallon of water.

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Aquariums are an excellent and delightful hobby to decorate the house and explore a world unfamiliar to the surface. Fish are one of the top five most common pets to own because they are perfect introductory pets for children to teach them responsibility. Once children learn how to properly care for fish, they can be ready for other pets like cats or dogs.

A well-decorated freshwater tank can be an accent or centerpiece to the entire room. However, it can be difficult to determine which fish to buy when there are thousands available. Pet stores like Petco and PetSmart have walls of hundreds of fish so it can be hard to decide which to buy.

Dip a toe into aquarium ownership without breaking the bank by looking for these freshwater fish.

Freshwater Fish to Buy on a Budget

Remember, prices may vary depending on the location, store, type, and size of the fish. Some fish will cost more because they are larger and older, while some small fish will be expensive because of their colors, fins, and rarity.

Feeder Fish (Goldfish)

Goldfish in aquarium with green plants

Goldfish are popular starter fish but can be expensive based on their size and type. Feeder goldfish are cheaper and can be just as pleasing.

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$.10-$.502 inches4 yearsGold, silver, orangeGood with others of similar size

Feeder fishes are any type of fish that are inexpensive to purchase and are used to feed other fish. The most common types of feeder fish are small goldfish, platys, and mollys. However, they can be a perfect place to start because they are the cheapest fish to buy, and families give them a better life than being fed.

Neon Tetras

Multicolored tetras

Pet stores have tetras that can glow in the dark under a black light, but they will cost more than regular-priced tetras.

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$32 inches10 years (depending)AssortedGood with (3 or more)

Neon tetras are lovely, colorful, bright freshwater fish that work well in small schools. Families should purchase two or three Neon Tetras at a time because they will become stressed when alone. They have a distinct blue stripe on their bodies which glow with proper lighting.


Xiphophorus maculatus - Platy Mickey Mouse

The Mickey Mouse Molly are a favorite with kids because of the Mickey Mouse-like pattern on their tails.

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$42 inches4 yearsAssorted, rainbow, black and white, gold, orangeSocial (3-4 in a group)

Platys have bright colors, and jolly personalities, and come in an assortment of styles and colors that a tank of just platys will not disappoint. They are schooling fish, meaning they do better with other platys in the tank. A 10-gallon tank plus two or three platys makes an excellent present or starter tank.

Molly Lyretails

Closeup shot of a mollies yellow fish on the aquarium

Mollies are peaceful and friendly fish that can live happily with other mollies and fancy fish.

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$43-6 inches5 yearsBlack, silver, dalmatianSocial but aggressive

Molly Lyretails are beautiful fish with unique tail fins that have two longer points at the end. These fish can come in a few colors, but most commonly come in black, white, and a combination of both to mimic Dalmatian patterns. They are friendly with other fish of similar size but will become aggressive if the tank is too crowded. Buy Molly Lyretails in a 10–15-gallon tank with two or three other tankmates with plenty of decoration.

Balloon Mollies

isolated mollies

Dalmatian fish are exotic and brings a clash of colors and contrast into a fishtank.

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$52-3 inches3-5 yearsBlack and orangeSocial (2-3)

Balloon Mollies are a different variant of mollies. These fish are easily recognizable by their balloon-like appearance while they swim. Buyers should consider buying female Balloon Mollies because they are slightly larger than males. Like other mollies, they do well in small groups and will become stressed when alone or with too many tankmates.

Serpae Tetras

Cardinal tetra(Paracheirodon axelrodi)

Cardinal tetras have lovely blue and silver hues like their neon counterparts, but with more variety in their coloring.

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$41-2 inches7 yearsOrange, red, blackSocial (6-7)

Serpae Tetras are mostly inexpensive but should be purchased together in groups for optimal health. These fish will become stressed and aggressive in small groups of 3 or less. Still, they are small fish and can swim well with others with plenty of space and decoration to move through. A tank of just Serpae tetras can be an excellent option to start with a couple in a small tank.

Algae Eaters

Fish Ancistrus in aquarium

Plecos are bottom-dwelling fish that help keep the tank clean and can grow bigger depending on the species.

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$41-2 inches7 yearsOrange, red, blackSolitary

Algae eaters are an excellent option for all freshwater fish tanks. They are natural cleaners, capable of feeding on the loose bits of algae in the tank, helping to keep it clean. However, algae eaters should not be seen as a filter replacement as they will not clean as well as a dedicated filter.

Owners must have a strong cover on their tank because they may try to escape from the top while feeding. Algae eaters are social and good with other fish but may get into fights with other bottom feeders. A single algae eater in a tank of a couple of other fish is more than sufficient for a tank on a budget.

Zebra Danio

Danio fish. Aquarium macro closeup background.

The Danio stripes are excellent camouflage, and decoration for a large tank.

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$31-4 inches3-5 yearsBlack and white, green, orange, blue, redSocial (6 or more)

Zebra Danios (zebrafish) are delightful small fish that have elegant black and white stripes racing down their body. In groups, they blend well together, preventing predators from accurately attacking them. They are peaceful fish that work well together in small groups of six or more. However, in smaller tanks of just zebrafish, they can live together comfortably. Owners should have a secure lid because they are prone to jumping out of the water. Additionally, because they come in a variety of colors, a tank of only zebrafish will look spectacular.


Freshwater Aquarium Fish

Larger fish like to poke at the long tail of a swordtail, so they should be kept in tanks with similar sized fish.

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$46 inches5 yearsRainbow, red, orange, gold, neon, green, yellowSocial (3-4)

Swordtails are colorful and interesting fish because the bottom of their tailfin extends out like a sword. The males can be aggressive with other males, but not with females. Owners should purchase three or four swordtails together with a single male and the rest female. They are strong and resilient to changes in the water, making them perfect freshwater, starter fish.

Red Eye Tetra

Closeup shot of a red tetra fish in a clear aqua aquarium with lush aquatic plants in the background

Tetras become stressed by living alone or when the tank is too crowded, making them ill.

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$32 inches5 yearsRed, silver, white, blackSocial (3-4)

As their name implies, these fish have distinct red eyes while the rest of their body can be various colors. On a budget, owners should aim to have three or four at a time, but a larger tank should have six. They will stay together and claim a portion of the tank as their territory.

Still, they get along well with other fish and are generally peaceful. Tetras enjoy swimming with similar and other fish, making them cheap and friendly tankmates.

Mystery Snails

Freshwater Snail - Ampullaria

Freshwater snails are very pleasant and will enjoy roaming around a wide tank.

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$3-$51-2 inches1-2 yearsBlack, blue, gold, purple, chestnut, oliveSocial and friendly

Mystery snails are not as mysterious as the names suggest, but they are a delightful addition to any freshwater tank. They are fairly small and feed on algae around the tank. Mystery snails get along well with other fish and bottom-dwellers. Owners will commonly find their snails sticking to the glass walls to feed off algae. Sometimes they will be near the very top of the tank, making it a fun hide-and-seek game of where they are.

Tiger Barbs

Striped Barbus fish in the aquarium

Barbs are pleasant fish that get along with like-sized tankmates, and will feed on a few fish flakes twice a day.

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$42-3 inches5-7 yearsBlack, gold, rose, orange, green, dalmatianKeep with Barbs (6 or more)

Tiger barbs are relatively short but have a fierce hierarchy within their schools. Owners should keep a tank of barbs together to prevent them from fighting with smaller fish or fish with fancy tails. Despite that, Tiger Barbs are remarkably interesting because they have tiger stripes with matching coloring to stand out among other fish. Their wider bodies and thinner frames add diversity to a tank over the long and slender fish.

Fancy Guppy

Guppy Multi Colored Fish

Guppies are lovey fish with a wide assortment of colors that kids will love in their personal tanks.

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$2-$32 inches3 yearsRainbow, pink, green, gold, black, blue, yellowSocial (3-4)

Guppies are adorable and delicate fish with beautiful fins that flow while swimming in the tank. They are an immediate delight to see and very inexpensive, allowing for more to be in the tank. Fancy guppies like being in groups of three or four, but more are possible depending on the size of the tank. With a variety of colors and styles of fin shapes, a tank of just fancy guppies is great for a starter tank on a budget.

However, owners be careful because they like to swim at the top of the tank and can be caught in strong filters.

Mixed Angelfish

Angelfish, scalar blue fish in a home aquarium



are beautiful and can be aggressive around feeding time.

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$5-$66 inches10-12 yearsGold, black, white, tricolor, silver, veiledTerritorial

Angelfish are gorgeous animals and are popular for larger tanks. Their taller bodies and thin, flowing fins are iconic and mesmerizing to viewers. However, angelfish are territorial and aggressive to smaller and slower fish. Owners should keep a couple of angelfish together with similar-sized fish to avoid confrontations. Otherwise, they are very peaceful and docile.


Dwarf gourami Trichogaster lalius tropical aquarium fish

Some species of gourami can reach 24 inches.

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$6-$72-3 inches (depending)20 yearsBlue, gold, pink, silver, redSocial, aggressive

Gouramis are one of the few fish on this list that do not mind being in a school or living alone with tankmates. However, gourami can become aggressive to smaller fish, so they should be kept with those of similar sizes. Interestingly enough, gouramis will surface to take gulps of air before diving again. Owners should keep the air above their tank at a similar temperature as their tank.

The biggest expense of buying an aquarium is the tank and filter. After the tank, the fish decorations can be expensive with gravel, rocks, caves, and statues. Freshwater fish are inexpensive to buy in comparison. While on a budget, purchase a large enough tank to have five or six fish that can be comfortable living together. 

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About the Author

Jorelle Baker is a writer at A-Z Animals, primarily covering pet care, fun facts about animals, and how humans and animals coexist together. He has been writing for his entire life, graduating William Paterson University with a Bachelor's degree in creative writing. He continued his studies at Animal Behavior College to work with animals at grooming salons and veterinary clinics. Jorelle lives in New Jersey and enjoys studying animals in myths and folklore with his cat Kana.

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