Freshwater Aquarium Fish Compatibility

Freshwater aquarium fish are easy to care and very enjoyable pets. They can easily live in a small 5 gallon tank and love swimming in a 100 gallon tank. You can house your pet in a glass or acrylic tank. Use different substrates and decorative ornamental pieces, like rocks, live plants, plastic plants, and even some fancy plastic aquarium toys. The tank can be lit up with a bulb and you can place a filter to keep the water clean. You can even place a heater to provide some warmth to them. You can use normal tap water as the medium for your pet to live in.

As an aquarium enthusiast, you can choose from a variety of fish. You should keep in mind that the fish should be similar in size to avoid larger ones from picking on the smaller ones or the tiny ones eating up the fins of the larger fish. Also, they should not compete with each other for food, as it will result in starvation and death of the weaker lot. You need to choose the right pet for your aquarium so that they can peacefully exist alongside each other.

Basics of Their Compatibility

Fish are very sensitive and delicate creatures. Any amount of stress can lead to their untimely death. The freshwater fish are divided into 3 categories according to their behavior:

  • Community Fish: They are peace-loving and happy-go-lucky. They do not get into fights and are compatible with all the others. You can safely mix and match different community species in your tank.
  • Semi-aggressive Fish: These are a bit high-strung and will not shy away and would occasionally nip and bite other fish. They tend to be peaceful when small, but as they increase in size they turn into fin-nipping rogues. They will chase and tire the others. They are good for community tanks, but make sure you keep an eye on them as they grow bigger in size.
  • Aggressive Fish: Just as the name suggests, these fish can be called the fighters. They love to pick on little ones and are not compatible with any other species. They can live around with other aggressive ones of their own kind or size. However, they have a habit of bullying weaker ones by pushing them around.

The Compatibility Chart

Category Community Semi-aggressive Aggressive
Anabantids Dwarf Gourami

Flame Gourami

Opaline Gourami

Pearl Gourami

Siamese Fighting Fish/Betta Fish

Spike-tailed Paradise fish

Honey Gourami

Kissing Gourami

Black Paradise fish
Aquarium Catfish Banjo Catfish


Chinese Algae Eater


Green Catfish

Leopard Catfish


Spotted Catfish

Upside Down Catfish

Bumble Bee Catfish
Charachins Black Neon Tetra

Black Phantom Tetra

Cardinal Tetra

Congo Tetra

Emperor Tetra

Flame Tetra

Glowlight Tetra

Head and Tail Light Tetra

Neon Tetra Fish

Rummy-nosed Tetra

Serpae Tetra




Penguin Fish

X-Ray Fish

Bleeding Heart Tetra

Black Widow

Buenos Aires Tetra

Silver Dollar

Red Belly Piranha
Cichlids Freshwater Angelfish

Blue Acara







Green Terror

Jack Dempsey

Red Oscar

Cyprinids Cherry Barb

Bala (Tri-Color) Shark

Black Shark

Blue Danio

Giant Danio

White Cloud

Zebra Danio

Harlequin Rasbora

Flying Fox

Green Tiger Barb

Red-tailed Shark

Rosy Barb

Tiger Barb

Tinfoil Barb

Killifish Lyretail
Livebearers Guppy fish



Swordtail Knife Livebearer
Loaches Clown Loach

Dwarf Loach

Horseface Loach

Unclassified Australian Rainbowfish

Boesmani Rainbow fish

Boesman's Rainbow fish

Bumble Bee Goby

Elephant Nose

Rainbow fish

Archer Butterfly Fish

This chart will help you know which ones are compatible. You can try keeping some of the community fish with the semi-aggressive species, but make sure you always have an eye on them. Do not introduce the aggressive ones to the tank, else most of your peace-loving fish will end up dead.