We understand that choosing a new fish for your tank can be puzzling. There are just so many options! But worry not, we are here to help you choose the best fish for a 20 gallon tank.
Selecting the right fish is very important. No matter what you choose, your fish must be compatible with your routine and the fish tank. For a healthy bond between a pet and its owner, the relationship should be fun, not just a responsibility.
Have you ever wondered which fish could bring the most joy and color to your tank? Before you make a choice, let’s explore the options.
In today’s article, we will be covering the 21 best fish for a 20 gallon tank. In addition, we will also discuss their size, appearance, and behavior towards tankmates. Moreover, we will explore their natural habitat and how can they thrive in a 20 gallon tank.
So, without wasting any time, let’s discuss the best fish for you.
Betta Fish
Betta fish is one of the best fish for a 20 gallon tank. They are well-adapted to small water bodies because of their natural habitat. They thrive in shallow, stagnant waters such as rice paddies, and drainage ditches. These are limited water bodies so the fish is naturally adapted to live in tight spaces.
Betta fish have beautiful colors and fins, so adding one to your 20 gallon tank is great! Although they have vibrant bodies, they only grow up to 2.5 to 3 inches. This small size is a plus point, as they will fit in the tank easily and have ample space to swim in.
Betta fish are aggressive and often territorial, especially the males. However, if you set up a tank that mimics their natural habitat, the fish can thrive without any problems. You should add a lot of vegetation and hiding spaces for the fish. It relieves stress and mimics their natural home.
Ember Tetra
Ember Tetras originate from small, slow-moving waters in Brazil’s Araguaia River basin. These habitats have limited swimming areas and heavy vegetation. So, these tetras are naturally accustomed to small water spaces.
As the name suggests, this fish has a vibrant orange-red color. In addition, it has a very small body size of about 0.8 inches. This small size makes the Ember Tetra ideal for a 20 gallon tank. Moreover, the bright reddish color adds a pop to a well-planted aquarium. In essence, this small fish is very easy to care for, and a small tank effectively mimics their natural habitat.
Ember Tetras are very peaceful and social. They prefer to thrive in groups that provide a feeling of safety. However, make sure they don’t have any aggressive tankmates. Bigger fish might think of them as food, so avoid having larger tankmates.
Dwarf Puffer
Dwarf Puffers also known as Pea Puffers, originate from slow-moving waters in India. Its natural habitat includes a lot of vegetation, like small ponds and streams. These environments are naturally small, so a 20 gallon tank is great for the Pea Puffer.
As the name suggests, Dwarf puffers are very small. They have a maximum body size of about 1 inch. Additionally, they have striking body colors, like a mix of green and yellow. These beautiful bodies are adorned with dark spots. All in all, this is the best fish for a 20 gallon tank, thanks to its small size and captivating look.
Interestingly, this tiny fish has an active and curious nature. It is well known for its playful behavior. However, they can get aggressive and territorial, so it’s best to keep them alone or with other Dwarf Puffers.
Rummy Nose Tetra
Rummy Nose Tetras thrive in small water bodies. Its natural habitat includes densely vegetated and slow-moving streams of the Amazon Basins. This fish naturally likes small spaces, so a small tank is perfect!
These tetras have a vivid red nose and a silvery body. Additionally, they boast a black and white striped tail which adds to their look. This fish has a small size of 2 inches. So, the size and the looks make them one of the best fish for a 20 gallon tank.
Rummy Nose Tetras are peaceful and active. They thrive in groups, so if you want to add more than one to your tank, give it a go! A group of 6 is usually suggested. Although this fish is compatible with many tankmates, it can get stressed out easily. So, ensure their tank is clean with no bullies around.
Swordtail fish
Swordtail fish originate from small streams and ponds in Central America. Due to this natural habitat, they have adapted to confined spaces. However, they do require a lot of hiding spots. Interestingly, this fish has a hardy nature and thrives in a variety of environments.
Swordtails have a vibrant appearance and a distinct body shape. They come in a variety of body colors like red, orange, green, and even black. As the names suggest, this fish has a swordlike extension on its body. Especially the males have a prominent and elongated tail fin that resembles a sword. However, their body size is only 4 to 5 inches that can be managed in a 20 gallon tank.
Despite the sharp looks, Swordtail fish are peaceful and social creatures. They co-exist with peaceful and non-aggressive fish. Additionally, they have a lively and active lifestyle, so they do need some space to swim freely. So, it’s best not to overcrowd the tank.
Dwarf Gourami
Dwarf Gouramis thrive in shallow and densely vegetated waters. So, the fish is naturally adapted to confined spaces. In captivity, Dwarf Gouramis flourish in small tanks where they can establish their own territories.
Dwarf Gouramis have small bodies ranging between 2 to 3 inches. In addition, they have bright colors with blue-green and reddish-orange hues. Moreover, they have a long thread-like ventral fin which completes the look. This beautiful appearance and compact size make them the best fish for a 20 gallon tank.
Dwarf Gouramis generally have a peaceful nature. However, the males can be aggressive and territorial. It’s best to have 2 females for 1 male in the tank along with a lot of hiding spots. Additionally, ensure the tank is clean and free from any stress factors.
Apistogrammas
Apistogrammas inhabit slow-moving tributaries and small water bodies in the Amazon basin. These environments have shallow water and a lot of vegetation. Thus, this fish is naturally used to shallow and congested waters.
Apistogrammas typically grow up to 2.5 inches. They have colorful bodies that are selectively bred for an intense red or orange color. Additionally, their body is adorned with many colors like bright blue, red, and yellow. Because of this beautiful body and its small size, this is one of the best fish for a 20 gallon tank.
Apistogrammas generally have a peaceful nature. However, they can be quite territorial and aggressive while breeding. The key is to add a lot of hiding spots and plants in the tank to reduce any stress and aggression. Additionally, this fish thrives in the lower half of the tank, so you can add tankmates that flourish in the top half of the water.
Cory Catfish
Cory Catfish thrive in slow-moving streams and shallow waters. Their natural habitat includes small, congested waters with a lot of vegetation. So, this fish is naturally adapted to small spaces.
The Cory Catfish has a small body size ranging between 2 to 2.5 inches. In addition, it has a beautiful, armored body. This small size and visual appeal make it the best fish for a 20 gallon tank.
This fish has a peaceful nature towards tankmates. It thrives in groups with its own species and other non-aggressive fish. Additionally, this fish is a bottom dweller who likes scavenging the tank for food. So, they add beauty and cleanliness to your tank.
Endler’s Livebearer
Endler’s Livebearer originates from small, shallow water bodies in Venezuela. These fish are naturally accustomed to limited space due to their natural habitat. Moreover, this fish is highly adaptable as it does not require vast territories.
Endler’s livebearers have vibrant colors. The males usually have a striking combination of orange, green, and black. On the other hand, the females have a silver or gray body. Overall, this fish can grow up to 1.8 inches long. So, it is pretty manageable in a 20 gallon tank.
Endler’s Livebearers have peaceful behavior toward tankmates. They are well known for their compatibility in a community tank. This fish is not aggressive so most tankmates can get along. Additionally, it has a social nature and thrives in groups.
Zebra Danios
Zebra Danios is native to small freshwater bodies. Its natural habitat includes slow-moving streams and ponds with smooth a substrate. These environments provide a confined area to thrive in, so this fish is well adapted to small spaces.
This fish has a beautiful body with colorful hues of blue. Due to selective breeding, this fish can also exhibit hues of red, green, orange, and pink. Additionally, its body is adorned with silver horizontal stripes that resemble a zebra.
Thanks to selective breeding, this fish is just full of diversity! It has many types, each with its own physical characteristics and color pattern.
Generally, the Zebra Danios can reach a maximum body size of 2 inches. The small size, paired with the visual appeal makes it the best fish for a 20 gallon tank.
Zebra Danios have a peaceful and social nature. It is suggested to keep at least 5 of them in one tank. They like to form groups and play as they have an active lifestyle. However, it’s important to know that this fish can be fin-nippers. If they have tankmates with slow speed and long fins, they might tank a bite or two from their fins!
Kuhli Loach
The Kuhli Loach belongs to the streams and rivers of Southeast Asia. Its most preferred habitat includes shallow and slow-moving waters. Kuhli Loaches inhabit freshwaters with a lot of plants and hiding spots. These habitats provide limited area so the loach has adapted to small spaces.
In terms of looks, the Kuhli loach has black or brown stripes along the length of its body. These stripes contrast with the light body colors. The body colors can range from pale yellow to cream or pinkish-orange. These body colors might become pale or dark depending on their mood and stress levels. In addition, this fish has sensory barbel near its mouth that elevates its looks.
Kuhli loaches are well known for their social nature, which makes them ideal tank mates. This fish is compatible with tank mates that are not aggressive and don’t compete for food. Moreover, Kuhli loach is nocturnal, so it’s more active at night.
Bolivian Ram
The Bolivian Ram is native to the slow-moving waters of the Amazon Basin. It inhabits streams and small rivers with calm currents and confined spaces. This fish has adapted to small spaces because of its natural habitat.
The Bolivian Rams have a small body size of 3 inches max. Unlike other fish species, the males are slightly larger than the females. Additionally, this fish has vibrant body colors including yellow, blue, and red hues. Along with that, black vertical bands adorn its body and add to the look. All in all, its small size and striking appearance make it the best fish for a 20 gallon tank.
Bolivian Rams have a peaceful temperament. They are generally non-aggressive and get along well with other peaceful fish. However, they can become territorial while breeding. To resolve this issue, make sure you have plenty of hiding spots in the tank. Despite being mildly aggressive, this fish is well known for community tanks.
Cherry Barb
In the wild, Cherry Barbs inhabit small, slow-moving streams and ponds. These environments have limited area just like a small fish tank. Thus, Cherry Barbs thrive easily in a 20 gallon tank as it mimics its natural home.
Just like a cherry, this fish has a small red body reaching a maximum length of 2 inches. The males usually have a more intense red coloration while the females go with a more subtle red. Because of its small size, this fish doesn’t require a lot of space to swim. Their moderate size and striking appearance make them appealing for any small tank.
Cherry Barbs have a peaceful and non-aggressive nature. They can coexist with similar-sized tankmates. Moreover, this fish makes small schools, thanks to its social behavior. All in all, this fish is friendly, compatible, and beautiful to watch. However, avoid larger and more aggressive tankmates.
Harlequin Rasbora
Harlequin Rasboras naturally inhabit small water bodies. In the wild, these fish are found in shallow streams and ponds. Thus, they have a natural adaptation to thrive in limited spaces.
Harlequin Rasboras have small bodies reaching up to 2 inches in length. In addition, they have shimmering, bodies with a copper-like color. these bodies are adorned with black triangular patches that complete the overall look. This attractive look paired with a small size makes them the best fish for a 20 gallon tank.
Harlequin Rasboras are peaceful and social fish. They are well-known as community fish because of their schooling behavior. However, it’s important to note that these fish can get stressed easily. So, make sure they don’t have aggressive tankmates.
Galaxy Pearl Danio
Next on our list of best fish for a 20 gallon tank, we have the Pearl Danios. They are native to small water bodies such as streams and ponds. Their natural habitat has conditioned them to thrive in small water bodies. A 20 gallon tank is the best option for housing this fish as it mimics the fish’s natural habitat with limited space.
Pearl Danios have iridescent scales covering their whole body. These scales have intriguing color hues with a mix of blue and gold. This fish has a slender body that reaches up to 2 inches in length. This size makes them ideal for a small tank. Along with that, its vibrant presence can add a splash of color to any fish tank.
This fish has a peaceful and active nature. It likes to form groups and move and swim in symphony. This social behavior with small peaceful fish makes them a harmonious add to small tanks.
Bristlenose Catfish
Bristlenose Catfish inhabits slow-moving, shallow streams and rivers in South America. These habitats naturally have slow and limited water flow. This environment makes the Bristlenose Catfish naturally adapted to small water tanks.
The Bristlenose Catfish has a unique appearance. It has a flat body with unique bristles near its snout. This characteristic is more prominent in males. Additionally, their body is about 4 to 6 inches in length. So, they can fit well in a 20 gallon tank with plenty of space for a swim.
Bristlenose Catfish have a peaceful nature. They are compatible with most non-aggressive fish. Additionally, they have an algae-eating habit which keeps the tank clean. Moreover, this fish is nocturnal, so it’s more active when other fish are not.
Goldfish
Goldfish come from small ponds and slow-moving streams. These habitats provide confined spaces, just like a fish tank. Additionally, Goldfish are hardy and adaptable, which makes them the best fish for a 20 gallon tank.
Goldfish are known for their striking appearance with flowing fins. They come in many body sizes however, most of them are small enough to fit in a 20 gallon tank. Their manageable size and beautiful gold color make them ideal for any small tank.
Goldfish have a peaceful nature as they can co-exist with almost any tankmate. However, the tankmates must be non-aggressive as well.
All in all, this fish is a classic choice for many aquarists around the world because of its beauty. But it is important to note that it produces a lot of water. So, you will have to manage a good filtration system if you add a goldfish to the tank.
White Cloud Minnow
White Cloud Minnows belong to China’s White Cloud Mountains. These environments have shallow water with abundant vegetation. Thus, they provide limited space for movement. Due to this natural habitat, the White Cloud Minnow has adapted to survive in small spaces.
The White Cloud minnow has a small body with vibrant colors. Its maximum body length is about 1.5 inches. Moreover, its body boasts a silver color with red-tipped fins. Additionally, its body is adorned with unique horizontal stripes. Thanks to this beautiful appearance and compact body, it is one of the best fish for a 20 gallon tank.
Known for their peaceful and social nature. Typically, they thrive in groups of five or more. This natural movement relieves stress and promotes its shoaling behavior. All in all, this fish is compatible with a variety of non-aggressive tankmates.
Scarlet Badis
Scarlet Badis originate from shallow, slow-moving waters in India. Its natural habitats include small ponds so it’s naturally accustomed to small spaces. If you can manage a small 20 gallon tank with good water quality, the fish is a great option.
The Scarlet Badis have vibrant bodies with red and blue hues. Their bodies are also adorned with intricate patterns that add to their overall look. Additionally, they have a really small body of less than 1 inch. With all these qualities combined, this is the best fish for a 20 gallon tank.
In terms of nature, Scarlet Badis is very peaceful. It prefers calm and vegetated tanks with a lot of hiding spots. This temperament makes them compatible with most non-aggressive tankmates.
Spotted Blue-eye fish
The Spotted Blue-eye fish thrives in small water bodies like ponds and streams. Its natural habitat makes it well-suited for a 20 gallon tank.
The Spotted Blue-eye fish has a small and slender body. It reaches about 1.5 inches in length. Moreover, its body is covered with striking blue spots and shimmering scales. These characteristics make this fish best for a small tank.
Spotted Blue-eye fish is well known for its peaceful nature. It has a calm nature and coexists with non-aggressive fish. Overall, Its temperament, small size, and visual appeal make it the best fish for a 20 gallon tank.
Dwarf Suckerfish
The Dwarf Suckerfish thrives in small streams and shallow water bodies. This natural habitat has a limited swimming space, just like a 20 gallon tank. As it is naturally adapted to small water bodies, it is one of the best fish for a 20 gallon tank.
The Dwarf Suckerfish can only grow up to 2 inches long. Additionally, their bodies are very slender so they can move easily in limited water. Additionally, they have striking patterns that add visual value to the tank.
This fish is peaceful and thrives in groups. Its social nature reduces stress and promotes its natural behavior. Moreover, this fish likes to eat algae, so you don’t have to worry much about scraping algae off the tank walls! However, ensure they don’t have aggressive tankmates and maintain basic tank hygiene.
FAQ’s
How many fish for a 20 gallon tank?
The number of fish you can add to a 20 gallon tank depends on the species of fish. For example, you can add 6 to 8 guppies or tetras in a 20 gallon tank. If you have aggressive fish then it’s better to use a bigger tank.
As a general rule, for each inch of fish, add a gallon of space.
Biggest fish for 20 gallon tank?
Dwarf Gourami is one of the biggest fish that can be kept in a 20 gallon tank. They can grow up to 3.5 inches in length. They also have a peaceful nature.
The Bolivian Ram is also a good option for small fish tanks. Its body size reaches about 3 inches in length which makes it one of the best fish for a 20 gallon tank.
Colorful freshwater fish for 20 gallon tank?
Neon Tetras are one of the most colorful fish for a small tank. In a 20 gallon tank, you can add a school of 6 to 10 tetras. But make sure you’re not overcrowding the tank.
Betta fish is also one of the best fish for a 20 gallon tank. It has a vibrant body that adds a splash of color to any fish tank. However, they have territorial behavior so, it’s best to keep them alone.
Conclusion
So this was all about the best fish for a 20 gallon tank. All in all, we discussed 21 different fish along with their natural habitat and how they align with a small tank. Moreover, we explored the appearance of these small fish and how they elevate your tank’s look. Additionally, we talked about each fish’s behavior and how it can thrive and coexist in a small space.
Let me ask you: What fish do you think is best for a 20 gallon tank? Share your thoughts with us in the comments below!
Lastly, no matter which fish you choose for your tank, make sure it is compatible with the space. Additionally, try to mimic its natural habitat and diet. Ensure that the tank isn’t overcrowded. Follow these simple guidelines and make a harmonious Biotope!