Stocking Your Aquarium Evenly With the Correct Number of Fish

Stocking Your Aquarium Evenly With the Correct Number of Fish

One of the factors often overlooked when choosing fish for a community aquarium is the level the fish prefer. Choosing fish that prefer swimming at different levels will result in a far more attractive aquarium, while at the same time assuring that your fish will not have to compete for space. It will also reduce the stress that occurs when fish have to battle for territories.

Popular fish that swim at any level include:


Pearl Danio
Rosy Barb
Upside Down Catfish
Zebra Danio
Top Level Fish
Top dwelling fish add movement and color at the top level of the aquarium, which often has very little decoration. Many fish that prefer the top level are surface feeders in nature and have upturned mouths designed for top feeding. They hang at the surface waiting for the next meal to come along.

Keep in mind that some of these top-level species are strong jumpers. Hatchetfish are known for being able to leap several feet out of the water. Even fish that don't normally jump may jump when startled by loud noises or sudden movements. Take care to keep the tank well-covered, and close the lid promptly after feeding or performing maintenance.

Popular top-dwelling fish include:

Common Hatchetfish
Halfbeak
Popular top to mid-dwelling fish include:

Boesmans Rainbow
Blue Gourami
Congo Tetra
Dwarf Gourami
Guppy
Kissing Gourami
Neon Rainbowfish
Pearl Gourami
Pencilfish
Swordtails
Middle-Level Fish
The middle level is the focal point of the aquarium and should be populated with plenty of active fish. Schooling fish, including most of the Tetra species, as well as some of the Barbs, are excellent for the middle level of a community tank. Mid-dwelling fish are often selected as dither fish for cichlid tanks, particularly schools of active fish.


Larger fish such as Gouramis, Rainbows, or Angels also make interesting mid-level fish. However, it is important to remember that slower moving fish with long flowing fins may be picked upon by smaller, faster-moving fish. Barbs are particularly well known for nipping fins. Avoid combining them with Angelfish or Bettas. Also, remember that many Gouramis aren't tolerant of their own kind, so do your homework before adding them to the mix.

Popular mid-dwelling fish include:

Black Widow Tetra
Emperor Tetra
Glassfish
Goldfish
Head and Tail Light Tetra
Rummy Nose Tetra
Silver Dollar
Silver-tipped Tetra
Tiger Barb
Bottom-Dwelling Fish
Bottom-dwelling fish lend interest to the lower levels of the tank and often help turn over the substrate. You will note that most of them have mouths that point downward, making it easy for them to scour the tank bottom for morsels of food. However, do not fall into the commonly held myth that bottom dwellers do not have to be fed. All too often bottom-dwelling fish are under-fed. They cannot subsist only on leftovers from the other fish.

Remember that the top and mid-dwelling fish will get to the food faster. Including sinking foods when feeding will ensure that those living in the lower portion of the tank receive enough food.


Some bottom-dwellers are nocturnal and should be fed after turning the lights off for the night.

Popular mid and bottom-dwelling fish include:

Bolivian Ram
Cardinal Tetra
Cherry Barb
Clown Loach
Discus
Headstander
Neon Tetra
Snakeskin Gourami
Popular bottom-dwelling fish include:

Adolfo's Cory
Bandit Cory
Pictus Catfish
Kuhli Loach
Kribensis
Panda Cory
Weather Loach
Choosing Fish
Always research the fish you are interested in for your community aquarium. Although swimming levels are a factor; water parameters such as pH, temperature, and water hardness, are quite important when combining fish in a community aquarium.

For a quick reference, here is a level chart that lists 100 community fish separated by the level they prefer. Don't forget that your fish must also be compatible with preferred water conditions, size, and temperament.