There are many fish that don’t need a heater, but can make perfect pets for low-maintenance aquariums. You may think you need to buy a heater in order to keep your fish alive, but many species don’t require such extreme measures of warmth!
If you’re a hobbyist who’s looking to set up your first or next aquarium, you’ll need to make sure that you plan ahead so that you don’t accidentally damage your fish! While there are plenty of factors to consider when setting up an aquarium, one of the most important things to think about is whether or not your particular fish needs a heater in its tank.
When you have an aquarium, the last thing you want to do is bring home fish that require a heater in order to survive the winter months. Unfortunately, some fish need this heater just to stay alive, and if it breaks or malfunctions it can be devastating to your fish population.
Getting a fish tank can be a very rewarding hobby, but it’s also one that requires a lot of maintenance to keep going.
Having the right filters, testing your water regularly, and having healthy fish are all important to keeping your aquarium alive and thriving, which can be tricky if you don’t have the right equipment or fish!
Luckily, these 15 popular fish don’t need much more than an occasional water change and some food to thrive in an aquarium! They’re perfect for beginners or folks who just want something low-maintenance on their desk at work!
Popular fish that don’t need a heater
Poecilia wingei (Endler’s Livebearer)
Endler’s livebearer is a small freshwater fish that can be found in Central and South America. Endlers are small, peaceful, and low maintenance. They are omnivores and will eat any type of fish food.
The Endler’s livebearer is one of the most popular fish for beginner aquarists because it is so easy to care for. The Endler’s livebearer does not need a heater or UV light to survive in an aquarium environment. In order to keep your tank clean, you should replace 50% of the water every week with fresh water. Keep your tank at a temperature between 60° and 82° Fahrenheit with an optimal pH level between 6.5 and 7.0.
Bloodfin Tetra (Aphyocharax anisitsi)
The bloodfin tetra is a small, peaceful community fish that can be found in the wild in the Amazon and Orinoco Rivers of South America. These are schooling fish and prefer to live with others of their own species, but they’ll also mix well with other types of small fish such as neon tetras, guppies, or minnows.
In the aquarium, they should be kept in a group of six or more to prevent them from becoming stressed out. They like water temperatures between 72 and 82 degrees Fahrenheit (22 to 28 Celsius). They’re very hardy and easy to care for, so it’s no wonder why these fish are a favorite among aquarists who want low-maintenance pets.
Odessa barb (Pethia padamya)
The Odessa barb, also known as the Pethia padamya, is a beautiful fish that does not require a heater. While it does well in temperatures as low as 64°F (18°C), this fish prefers to live in warmer water. It should be kept at 78°F (26°C) to make sure it is happy and healthy.
In addition, like other barbs, the Odessa barb needs plenty of plants to hide in and rest on. An ideal set up would include driftwood or rocks where they can stay hidden when they want to escape from light or other disturbances. These fish are very active during the day but do not need much space since they spend most of their time near the bottom of their aquarium.
One problem with keeping them without a heater is that it will be difficult for them to regulate their body temperature if it gets too cold outside.
White Cloud Mountain Minnow (Tanichthys albonubes)
The White Cloud Mountain Minnow (Tanichthys albonubes) is a freshwater fish that can live in cool water, with a temperature range of 59 to 72 degrees. These fish are typically found in Thailand and Malaysia. They are very popular in the aquarium industry because they don’t need a heater.
One thing you’ll want to watch out for is their tendency to jump, so if you have a lid on your tank make sure it’s secure! These guys get up to 5 inches long, which makes them a great candidate for larger tanks. Plus, like most coldwater fish they’re not picky about what food sources are available.
Sunset Variatus Platy (Xiphophorus variatus)
Also known as variable platyfish or variegated platy, Sunset Variatus Platy, also known as the platy, are a small freshwater fish that prefer temperatures in the range of 60 to 80 degrees Fahrenheit. They’re great fish for low-maintenance aquariums because they’re easy to breed and don’t need any special equipment. The fry can live on its own from birth, so there’s no need for a heater or filter.
These little guys grow up to be about two inches long! The Platy is an intelligent species and will react if it feels threatened by hiding or swimming away quickly. If you want more than one fish, it’s best to keep them with others of their kind because they may become aggressive towards other types.
They’re omnivores so they’ll eat both vegetables and meat, but watch out! They have a strong appetite and may overeat causing swim bladder problems or constipation due to overeating too much food.
You’ll know when your water needs changing when you notice brown algae starting to form on your plants or rocks.
Panda Corydoras (Corydoras panda)
The Panda Corydoras is a popular fish because they are very low maintenance, making them perfect for beginners. They will survive in most water conditions, and they only need to be fed once or twice per week. This makes them a great option for people who don’t want to worry about their fish as much. However, make sure that you still keep an eye on your tank’s pH levels and ammonia levels.
In addition to being easy to care for, the panda corydoras can grow up to 2 inches long and 2 inches wide. They also have distinctive black spots with white outlines on their body, which give them their name. If you’re looking for something with beautiful markings but doesn’t require a lot of upkeep, then this might be the perfect fish for you.
Fancy Goldfish (Carassius auratus)
Fancy Goldfish are a type of goldfish that come in a variety of shapes and colors. They don’t need a heater and prefer cooler water temperatures, making them perfect for low-maintenance aquariums with their long lifespan.
The downside is that they produce a lot of waste, which can be detrimental to the fish’s environment if not managed properly. Fancy goldfish will also grow quickly, so make sure you have enough space or else they’ll outgrow your tank within a few months.
Mosquito Fish (Gambusia affinis)
Mosquito fish are a great option for small tanks or outdoor ponds. They are native to North America and reproduce in large numbers. Mosquitoes will lay eggs on the surface of the water, where mosquitofish can eat them. Plus, they’re not picky eaters and will also consume tadpoles and other small insects that can be found in your backyard pond.
The only downside to mosquito fish is that they will also prey on smaller fry (fish under 2 inches) in your aquarium. To prevent this from happening, you’ll want to feed them live food like mosquito larvae instead of commercial flakes or pellets.
Bristlenose Pleco (Ancistrus)
Also called bushy nose pleco or bristlenose catfish, the bristlenose pleco (Ancistrus) is a popular fish among aquarium enthusiasts because it is one of the most low-maintenance fish out there.
This type of pleco stays small and doesn’t need to be fed very often, which makes it a great choice for those with busy schedules. In addition, the bristlenose pleco prefers to eat algae off of rocks and glass, so you won’t have to feed them any other food or clean their tank as often. All in all, this is a fantastic option if you are looking for an easy-going and carefree pet!
The Bristlenose Pleco (Ancistrus) is an ideal option if you are looking for an easy-going and carefree pet that doesn’t require too much upkeep.
Asian Stone Catfish (Hara jerdoni)
Asian Stone Catfish, or Hara Jerdoni, are a great fish for those with low-maintenance aquariums. They can live in unheated water and don’t need any additional filtration. They are also moderately sized, so they won’t eat all the food or eat other fish.
The only downside to these fish is that they don’t come in a variety of colors like some other fish do. They are a brownish color with white spots on their head. They typically grow to about 5 inches long but have been known to grow up to 7 inches long.
Celestial Pearl Danio (Galaxy Rasbora)
The Celestial Pearl Danio (Galaxy Rasbora) is a freshwater fish that originates from Southeast Asia. It prefers temperatures between 68 degrees and 77 degrees Fahrenheit, which makes it perfect for low-maintenance aquariums.
This small fish will grow to be about two inches long and has a lifespan of three to five years. They’re active during the day and live in schools. They’re peaceful towards other tank mates as well as humans, making them an excellent choice for beginners or children’s tanks.
Onesided Livebearer (Jenynsia lineata)
The Onesided Livebearer is a popular fish that doesn’t need a heater. There are six different species of Onesided Livebearers, but Jenynsia lineata is the most commonly seen in aquariums and freshwater tanks.
They have a life span of about three years and are easy to care for because they do not require any special requirements. This makes them perfect for low-maintenance aquarium setups.
The only downside is that they tend to be picky eaters, so it’s best to offer them a variety of foods. In addition, they don’t live long enough if kept in saltwater tanks or aquaponics systems with brackish water (although there are some reports suggesting otherwise).
Pygmy Sunfish (Elassoma)
The pygmy sunfish (Elassoma) is a very small species of fish, typically no more than 2 inches in length. The pygmy sunfish has some unique attributes that make it a great pet for low-maintenance aquariums.
It is primarily an herbivorous fish, meaning it will only eat live plants as food and does not require any additional meaty foods such as shrimp or fish. In addition, the pygmy sunfish can be housed with smaller species of fish, due to its small size. Finally, the pygmy sunfish is incredibly hardy and can tolerate water conditions that are much too hot or cold for other tropical freshwater fish species.
Dojo Loach (Misgurnus anguillicaudatus)
Also known as Pond loach, The dojo loach is a popular fish that doesn’t need a heater. These fish are livebearers, meaning they reproduce by laying eggs rather than releasing sperm in the water column.
Dojo loach are also one of the more peaceful bottom feeders and will only reach about 5 inches in length when fully grown, making them perfect for low-maintenance aquariums. Unlike other livebearing fish such as guppies or mollies, dojo loaches have a gestation period of 4 months or less which means new fry won’t be popping up every other day.
Macropodus opercularis (Paradise Fish)
The Macropodus opercularis is a popular fish choice for low-maintenance aquariums. This species is known as the paradise fish and can grow up to 8 inches in length. It has a pinkish body with black spots on its head and fins.
The Macropodus opercularis can be kept in water temperatures as low as 64 degrees Fahrenheit, making it an excellent choice for low-maintenance aquariums. They are great at eating algae from your tank’s glass and plants but may get territorial when defending their food sources.
When choosing a tank for this type of fish, make sure that you provide plenty of room for swimming space. If there are any rocks or other features in the bottom of your tank, consider removing them because these will most likely cause injury to your pet if they collide with them.
The Macropodus opercularis should also be kept in groups of two or more because they enjoy the company and will become stressed if they don’t have companionship.