Fish Care

20 Top Coldwater Fish for Fresh Water Aquariums

cold water fish

Not only will cold water fish add tranquility and colour to your fish tank, they are also easy to care for and, if properly cared for, can live a long and healthy life. Learn how to care for your finned friends with this helpful guide.

What are cold water fish?

Cold water fish, in the form of aquariums, refer to fish that do not need a heater to stay at tolerable temperatures in a typical indoor aquarium.

As the name suggests, “cold water fish” are fish that grow well at cold water temperatures. In fact, many cold-water fish are unable to tolerate the warm water that we usually keep tropical fish in. For that reason, many species of cold-water fish should be kept in species tanks only.

So why would anyone keep a cold water aquarium?

Typically, cold water tanks are cheaper (you don’t have to buy / use electricity with heaters) and low maintenance (you don’t have to worry about keeping water temperatures up).

In addition, algae often have a difficult time growing in cooler cold water tanks. As long as you keep your aquarium indoors, a cool room usually works well for most of the fish species below.

Care and maintenance

Cold water fish can brighten up an indoor tank and they can also enjoy their lives in the outdoor pond as well. Whether you have an outdoor or indoor aquarium, your pet home will need to meet certain requirements.

  • Temperature: Between 15 ° C and 20 ° C.
  • PH: Between 6.8 and 7.8.
  • Nitrite: Below 0.5ppm, 0 is complete.
  • Nitrate: Less than 40ppm, and 0 being ideal.

Depending on the type of fish you care for, these levels may change.

Setting up a cold water tank

Cold water fish need a wide tank to survive comfortably and the size of your tank will depend on how many fish you would like to keep.

Once you have your tank in place – protect from heat and full exposure to the sun – place your substrate inside. Gravel should be added to beautify and very easy way to clean it.

Before welcoming your fish into their new home, cycle your aquarium for at least a week. This will ensure that the water is clean, at the right temperature for its new inhabitants and allows for good bacteria to form. The water filter and thermometer will maintain water quality.


Feed your fish pellets or flakes. Feed both indoor and outdoor fish food that they can eat in less than five minutes.

Fish in outdoor ponds feed off their environment but will still need flakes or pellets. If they eat their food too soon, they will probably underfed. In this case, feed them once a day until they seem less interested.


Always change the water in your aquarium to keep it clean. Do this by removing only 25% of the water at a time. When changing water, make sure the temperature is right and free from chemicals. Use a siphon to remove any unwanted floating object.

Whether indoors or outdoors, all aquariums love to produce algae. For indoor aquariums, it is advisable to invest in an algae scraper or magnetic glass cleaner.

If you find algae in your pond, remove any overgrown plants. You can also add something new to your pond – snails. Snails are the most preferred method, as they have great ability to remove algae.

Fish types compatibility

Incompatible fish habitat can cause stress, disease and injury. Make sure you do your research to gain an understanding of the species that will live peacefully with each other.

Compatible indoor cold water fish species
  • Goldfish
  • Bloodfin tetras
  • Betta
  • Properties
  • Danios
Compatible outdoor cold-water fish species
  • Goldfish
  • Koi
  • Snails
Health care

Before deciding on your new fish, make sure they are free from disease or injury. Unhealthy fish will find it very difficult to adapt to their new home and will have a very short life span. Check your fish once a day to make sure they are in good condition and thriving in their aquarium.

Cold water fish are often infected with internal parasites and fungal infections. Look for any physical changes in your fish – changes in color, spots, bulging eyes or swelling are signs that your fish may be infected and, if left untreated, can infect the rest of the tank.

Yes, for beginners to aquarium hobbyists, it is important to look for fish that are cold water fish. Studies show that cold-water fish are readily available in the fish market and can thrive in freshwater lakes. Most importantly you should look for fish that do not need a heater.

  1. Paradise fish

cold water fish

Paradise fish is a beautiful species of gourami, reaching about 4 inches in length. Males have beautiful flowing fins and bright, vibrant colors on their body.

Paradise fish can be aggressive at times, and very delicate, so tank partners should be carefully selected. Give them a small space, at least 30 liters, as they like to swim around.

They prefer temperatures between 60 ° and 85 °, which should be ideal for a cold water aquarium. The paradise fish are easy to feed and work well in community aquatic environments where they live with the right tank partners.

  1. Panda Corydoras

“Corydoras panda.” by d50harry123 is licensed under CC BY 2.0

There are many varieties of corydoras, most of which are cold-water fish, but panda cory is the most commonly tolerant of low temperatures. They can survive in the range from 65 ° to 80 °.

Many people see this as an opportunity to keep them with a goldfish, especially since it usually reaches 2-3 inches, which many consider too large to be eaten by the goldfish.

However, corydoras has a number of spines and spikes on their bodies, and when a fish tries to eat it, it often gets stuck in the fish’s throat. In many cases, this results in the death of goldfish and cory. Corydoras are schooling fish, so keeping them in groups of at least six is ​​very helpful in expressing their personality.

  1. Goldfish

cold water fish

Fancy goldfish are a popular species of gold fish that often have more beautiful colours than other common variations. They share many features like other goldfish, they just look different.

These fish are ideal for cold water aquariums because their natural temperature requirements are quite low (this can be below 50 ° F). Most of the time they don’t even need heaters! The fancy goldfish will go with many other species and does not require much effort to keep them healthy.

  1. Bristlenose Pleco

“Bristlenose pleco” by bored-now is licensed under CC BY-NC-ND 2.0

Bristlenose plecos are small species of plecostomus catfish that reach only 3-5 inches in size.

They are often marketed as algae-eaters, adding a pleco to a tank is a much larger responsibility than adding a small algae eater like nerite snail.

However, they are popular because of their personality and prehistoric appearance. Even if they do little about algae control, it is still a good and wonderful fish to have.

  1. Celestial Pearl Danio

“Celestial Pearl Danios” by CheepShot is licensed under CC BY 2.0

Celestial Pearl Danio is an excellent breed that appeals to many aquarists. Their fun pattern and colors make them a great choice for anyone who wants to bring color to their tank.

These species are also a good choice if you prefer low-maintenance fish. While there are some other elements of care you will need to get used to, it is not very difficult to keep them.

These fish are the best in well-planted aquariums, the green plants make their colors stand out!We recommend this type to other aquarists at all times.

  • Size: 1 inch
  • Difficulty: Medium
  • Small Tank Size: 10 liters
  • Water Temperature: 73 ° F to 79 ° F
  1. Pygmy Sunfish

“Pygmy Sunfish in Aquarium (1975)” by Hunter-Desportes is licensed under CC BY 2.0

Pygmy Sunfish is an excellent species that is one of the best freshwater fish. The funny thing is that most people don’t know about this fish.

Of all the fish on the list, the Pygmy Sunfish is at the top, in terms of its ability to handle low water temperatures. At a temperature of 45 ° F, it is difficult to find another similar species. They are not too hard to care for and are rather active fish.

We strongly recommend that you take some time to do some research on these types before you decide to buy. Although they may not be extremely difficult, there are a few areas of care that you will need to get used to.

  • Size: 1.25 inches
  • Difficulty: Medium
  • Small Tank Size: 5-10 liters
  • Water Temperature: 45 ° F to 80 ° F
  1. Axolotl

Axolotl is a delightful creature that has grown rapidly in popularity over the past few years. While we put them on our list of the best cold-water fish, they are technically salamanders.

For such a unique animal, Axolotl is actually straightforward to keep. They do best in tanks without a heater and do not have many requirements for pleasant care.

  • Size: 8-18 inches
  • Difficulty: Beginner
  • Tank size: 20 liters
  • Water temperature: 57 ° F to 68 ° F
  1. Guppy (Poecilia reticulata)

Guppies are easy to care for and grow to about 2.4 inches in length. These fish thrive in a 5-liter tank with a minimum of 5 gallons of water and can tolerate a pH of 5.5 to 8.5. Females have gray stripes, and the back half is brightly colored.

You can decorate the tank with live plants, rocks and substrate. You can feed them with frozen foods such as shrimp and blood worm.

  1. White Cloud Mountain Minnow

“White Cloud Mountain Minnow” by mira d’oubliette is licensed under CC BY-NC-ND 2.0

Tanichthys albonubes are often sold as feeder fish in pet stores, but they make large pets due to their durability of survival at almost any tank size and temperature (as long as it is not too hot). It is sometimes known as “the poor the neon tetras” because of its inexpensive value, these days they come in many forms, such as albino, gold, and long stripes.

  1. Bloodfin Tetra

cold water fish

“Bloodfin Tetras” by jilldoo is licensed under CC BY-NC 2.0

Native to Southern Brazil and Paraguay, both the common bloodfin (Aphyocharax anisitsi), and the fake bloodfin (Aphyocharax dentatus) tolerate low temperatures as low till the mid-60s. Omnivores are peaceful, easy to care for and very strong. Thus, bloodfins are offered in many pet stores. These tetras are best kept in schools and they are active surface dwellers.

  1. Hillstream Loach

These impressive bottom dwelling fish come from South and East Asia. Although these fish are rarely seen in pet stores. Although, not all of them likes the cool temperatures, but most will tolerate temperatures that fall in the mid 60’s high Fahrenheit.

  1. Barb (Barbus tetrazona)

The fish is native to Borneo, Indonesia and Sumatra. It is an active and healthy species of fish that can live up to 6 years. They thrive in a 20-gallon aquarium and live in the middle of the water tank. Naturally omnivorous, barbs eat brine shrimp, bloodworm. To create a good breeding ground, you should make sure that the soft water of the tank is acidic with good leaves at the bottom.

They travel peacefully with tank partners like Danios, Loaches, Platys or Catfish. You should provide good lighting and a good substrate like a fish bed. Keeping them in school of five or more would be better.

  1. Zebra Danio (Danio rerio)

cold water fish

Zebra Danios is one of the most exciting freshwater species in the world, and it is peaceful. They are omnivorous, they are present at a temperature of 65 to 75 degrees Fahrenheit with a pH range of 6.5 to 8.

Natively found in the Ganges of East India, Zebra Danios is a curious fish that loves to run around and explore caves, holes and other parts of the aquarium. As species with a very high population, they prefer to live in shoals of 6 or 8 and grow up to 5 cm in size. When it comes to mating, these fish are mainly focused on breeding pairs. The female will lay 20-80 eggs or more.

Zebra Danios is inexpensive and easy to grow. Females usually spread their eggs under the tank, so they should be separated from adults.

  1. Dojo Loach

“Golden Dojo Loach” by Rhizae is licensed under CC BY 2.0

Want something bigger? This dog-sized fish can grow up to 10 to 12 inches in length and should not be kept with smaller species, such as pearl danio or cherry shrimp. Instead, try variatus platy, barbs, and other medium-sized fish that do not look like food. They are fairly cheap for their size and make a great addition to any large aquatic aquarium.

  1. Clown Killifish

This kilifish (Epiplatys annulatus) is another coldwater fish that can be kept in a community tank and other small species. They have blue eyes, their bodies are marked with broad vertical bands, and the males have a rock-like tail (hence their nickname “rocket killifish”). Like most killifish, they tend to swim on top of the tank, so make sure your aquarium has a hard cover that prevents them from getting out. Clown killifish prefers a pH of 6.5 to 7.8 with moderate water hardness, and will easily lay eggs in floating plants.

  1. Endlers livebearer


Poecilia wingei resembles a small version of its famous cousin, the guppy, in that it too is designed to display many unique colors and fin shapes. However, if you find the original livebearer, of the wild type Endler, it is very durable and can stay at room temperature with a wide pH ranging from 6.5 to 8.5. Also, they are very peaceful and get along well with most of the fish on this list. To fill them, just set up a tank with about two males and four females. Fill the aquarium with live plants and lots of hiding places and you will soon have a living factory, exploding when you have fish babies.

  1. Weather loach (Misgurnus anguillicaudatus)

Weather loaches are large species with a unique ability to detect storms, and thus respond to climate change. Being quiet and strong, these fish are ready to be kept inside the aquarium. The temperature of the aquarium should be kept at 55 to 77 degrees Fahrenheit. They grow up to 12 inches in length and have a habit of digging for water plants. The color of the fish varies from yellow, orange to pink. These fish have a long, body that is striped from head to tail. it is a dream fish for beginners. Loaches are naturally peaceful and can be easily kept with other fish.

The weather loach likes to hide inside rocks or simple objects like tubes, sand and gravel can be a good choice for a substratum.

  1. Rainbow shiner

“Rainbow Shiner(Notropis chrosomus)_0088_1” by scott361 is licensed under CC BY-ND 2.0

The rainbow shiner (or Notropis chrosomus) is definitely used in cool water and is known for its brilliant purple and pink hues, especially during mating season. These torpedo-like fish grow to 3 to 3.5 inches in length and can be kept with other peaceful fish that enjoy the same water parameters. Rainbow shiners are schooling fish, you should keep them in school for six or more.

  1. Sunset Variatus Platy

We have a special place in our hearts for the livebearers (or fish that breed early) because of how easily they make baby fish, but over the years, sunset variatus platy (Xiphophorus variatus) has become our favorite. Includes everything you would like for a perfect fish:

  • Available in a wide variety of colors and patterns
  • It is very durable and inexpensive
  • Only two to three inches long
  • It is alive but compatible with other fish and plants
  • It is easy to breed for fun

They can live in a wide range of temperatures and they often choose pH levels above 7.0. Include live plants and other fish in this list, and you are sure to love them!

  1. Cherry shrimp (Neocaridina davidi)

cold water fish

Cherry shrimps are a small variety of shrimp and are highly valued for their red color and easy care. Temperatures around 57 to 86 degrees Fahrenheit will work best for them.

Cherry are usually kept in groups of five or more. They have a gentle peace and a strong sense of humor. For best results, the pH level is maintained as 6.5 to 8. They grow up to 1.25 cm in height. While in the tank, these fish will need hiding places with holes such as coconut skin, java moss and other plants.

Commonly known for breeding faster compared to predatory animals, Cherry shrimps go well with peaceful tank partners like Otocinclus, pygmy cories, etc.

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