Which Freshwater Fish Species Are Best for Heated Tanks?

Find your perfect mix of freshwater fish

Neon Tetras in Planted Fish Tank

Илья Голубев / Getty Images

Keeping a tropical fish tank is a key achievement for many pet fish hobbyists. In comparison with a non-heated tank, all heated freshwater tanks should have a quality heater and a thermometer to keep your heater in check. Most tropical fish prefer a water temperature of 75 to 82F (24 to 28C), but may vary slightly by species. It is very important to maintain the correct temperature for your chosen species. Many of these tropical varieties do not appreciate cold water and can get sick and die if kept in inappropriate water temperatures. For most commercially available home aquarium heaters, it is easier for them to keep a larger volume of water at a consistent temperature than a smaller volume. In addition to improving your water chemistry, if you can go for a bigger tank, your fish will appreciate it!

Once you have your tropical tank all warmed up and ready to go, it's time for the fish! The most of following species are best for community tanks. For more aggressive inhabitants, follow these guidelines.

  • 01 of 10

    Betta Fish (Betta splendens)

    Male betta fish

    DEA / C. DANI / Getty Images

    Although not a true "community" fish, betta fish can be kept with a few other select species. Male betta fish get all the pretty colors and have a reputation for attacking other males, so only one male per tank. If you are keeping multiple betta tanks, do not allow them to be able to see each other! Male bettas can be kept with multiple female bettas, but sometimes breeding practices can get a little rough. Multiple females can be kept together, but you will not see the bright colors.

    Don't be alarmed if you see your betta lounging more than swimming. Since they swim with their pectoral fins, rather than their decorative tail, they require more rest periods than fish with functional tails.

    Species Overview

    Length: Up to 3 inches

    Physical Characteristics: Males come in a wide variety of colors; colors can change with age, genetics, diet and water quality; female bettas will have muted colors compared to males and shorter fins

  • 02 of 10

    GloFish® (Danios & Tetras)

    GloFish® Tank

     Jessie Sanders

    What is a GloFish®? Think of them as swimming GMOs, however, they present no threat to wild species. These fish are NOT injected with any dyes, but have been genetically modified with invertebrate genes to present with fluorescent pigmentation. Although they are brightly colored in natural light, blue LED lighting will bring out these vivid colors. When used alongside fluorescent decor, it creates a dramatic tank. These fish require not different treatment from their naturally-colored counterparts.

    Species Overview

    Length: Varies by species (1 to 2 inches)

    Physical Characteristics: Come in a variety of fluorescent colors, including yellow, green, pink, purple and blue; will not lose or change their color over time

  • 03 of 10

    Neon Tetra (Paracheirodon innesi)

    Two neon tetras

    Mirko_Rosenau / Getty Images 

    This brightly colored, small fish is best suited to live in larger schools. These fish are very easy going and have bright stripes of blue and red. If you catch them late at night, you may notice their coloration almost disappears!

    Neon Tetra (Paracheirodon innesi)

    Length: 1 to 2 inches

    Physical Characteristics: These slender fish have a bright blue top stripe and vibrant red bottom stripe.

  • 04 of 10

    Panda Cory Cat (Corydoras panda)

    Panda Cory Cat

    Prudtinai / Getty Images

    These bottom feeding fish, commonly referred to as a Corydora, is a peaceful fish who enjoy living in groups. Using their sensitive barbels, Cory Cats will sift through the substrate in search of tiny food bits. They prefer sandy or planted soil compared to larger gravel. There are many other varieties of Cory Cats that have a similar temperament and tank requirements.

    Species Overview

    Length: Up to 2 inches

    Physical Characteristics: Distinctive black patches on their eyes, dorsal fin and tail peduncle over a pearly, almost translucent body

    Continue to 5 of 10 below.
  • 05 of 10

    Guppy (Poecilia reticulata)

    Fancy guppy

    isoft / Getty Images

    The many varieties of guppies can withstand a wide range of temperatures, but are happiest in tropical environments. There are many "fancy" varieties of guppies available for purchase, but beware inbreeding techniques used to get specific colors or patterns. Multiple fish with spinal curvatures, missing fins or missing operculums are signs of a sick batch.

    As with all livebearing species, you may adopt one fish from the store, and suddenly, you have a dozen more. Guppies are great at reproducing and unless you can separate males and females, you will end up with many more guppies than you started with. Their gestation period is approximately one month, so this overpopulation can happen very rapidly.

    Guppy (Poecilia reticulata)

    Length: Up to 1.5 inches

    Physical Characteristics: Varieties of guppy colors, patterns and tail lengths varies significantly; numerous "designer" breeds are available all over the world

  • 06 of 10

    Swordtail (Xiphophorus helleri)

    Swordtail

    Paul Starosta / Getty Images

    The Swordtail fishes are members of the Platy family of fish and distinguished by the male's elongated ventral edge of their tail. Females will have a rounded tail. There are many varieties of swordtails available in the commercial market. They vary in coloration, but all have the same temperature requirements. Be sure to have a snug lid on your tank since swordtails like to jump.

    As with their guppy cousins, swordtails are livebearers and can quickly overwhelm an aquarium. Thankfully, it is very easy to distinguish males vs. females so you can keep them separated.

    Species Overview

    Length: Up to 4 inches

    Physical Characteristics: Come in a variety of colors; males are easy to distinguish from females from their elongated ventral tail fin

  • 07 of 10

    Dwarf Gourami (Colisa lalia)

    Male Dwarf Gourami

    Mirko_Rosenau / Getty Images

    Although a slightly harder fish to keep, the Dwarf Gourami makes a bright addition to a tropical tank. These fish like to have lots of places to hide, so make sure you choose appropriate decor. Usually, males will have a more vivid striped appearance than females.

    Like the betta, gourami have a specialized labyrinth organ, utilized for extracting oxygen from the air. That doesn't mean you can't skip your water changes!

    Species Overview

    Length: Up to 2 inches

    Physical Characteristics: Females are pale peach to silvery blue, whereas the males have bright iridescent blue and bright orange vertical stripes

  • 08 of 10

    Cherry Barb (Puntius titteya)

    Cherry Barb

    Besjunior / Getty Images

    A member of the Cyprinid family and cousin to the goldfish, Cherry Barbs have a slender, red body with dark marks along their lateral line. During breeding, males turn a brilliant "cherry" red, hence their unique name.

    Species Overview

    Length: Up to 2 inches

    Physical Characteristics: Variety of red pigments, from almost orange to deep red; black/brown markings can be found along their lateral line and dorsal ridge

    Continue to 9 of 10 below.
  • 09 of 10

    Bushy Nose Plecostomous (Ancistrus spp.)

    Yellow Bushy-Nose Plecostomous

    Mirko_Rosenau / Getty Images

    There are many species of Plecostomous that will do well in tropical tanks, such as the Bushy or Bristle-Nose Pleco. Keep in mind that not all species will stay cute and small. Some species of Plecostomous, such as many generally described "Plecostomous" in your local pet store, can grow up to 3 feet long! However, the Bushy Nose Plecostomous tops out at 4.5 inches, making him better suited for home aquariums.

    Species Overview

    Length: Up to 4 1/2 inches

    Physical Characteristics: Mostly brown with lighter brown to tan spots; named for multiple bristles around their mouths, used to detect food in the substrate and floating by; certain varieties can be orange or albino

  • 10 of 10

    Congo Tetra (Phenacogrammus interruptus)

    Two Congo Tetra

    Mirko_Rosenau /  Getty Images

    The Congo Tetra may have muted colors compared to some of the others on this list, but slightly iridescent skin and fins make them flash as they swim by. These fish are good community members and like schooling in groups of 5+ individuals. Congo Tetras do not do well with any aggressive fish in their home tank.

    Species Overview

    Length: Up to 3 inches

    Physical Characteristics: Mostly silvery body, but some may have a prominent orange band just above their lateral line; fins may be short or flowing and have darker or white edging

As with all tropical fish, maintaining a proper water temperature is key. Be sure to have a good aquarium heater and make sure it is working properly by having a thermometer in your aquarium or take daily readings. Most of the fish listed here a good community members and get along with many various species. Before adding any more "aggressive" fish, be sure you do your research and make sure they will not harass your other fish.

Article Sources
The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Bettas Need More Than Bowls. University of Illinois College of Veterinary Medicine