5 Best Fish Tank Ideas for A 40-Gallon Breeder Aquarium

5 Best Fish Tank Ideas for a 40-Gallon Breeder Aquarium

Due to its dimensions of 36 inches long x 18 inches wide x 16 inches high (91x46x41 cm), the 40-gallon breeding aquarium is very popular. Other 40-gallon tanks have a more rectangular base, but the 40-gallon breeder tank has a deeper base without being too tall so that you can easily reach inside to clean the aquarium and catch fish that you have bred. The 18-inch width also lets bigger fish to turn around more easily, making this one of the first footprints that allows you to keep either a larger solo specimen or community of fish. Keep reading to learn about our top 5 fish stocking ideas for a 40-gallon breeder tank.

1. The Flowerhorn Tank

Flowerhorn cichlid

This New World cichlid hybrid is famous for its colorful patterns and large nuchal, which grows on male heads. Flower horn fish are especially valued in certain Asian cultures because they are thought to bring good luck and prosperity. Although flowerhorns can be playful and friendly towards their owners, they can be quite aggressive towards other animals within their territory. Therefore, we recommend only keeping one in the 40-gallon tank with no other tank mates. As your pet grows, they will consume more food and need to be water changed frequently. After many years of enjoyment with the 40-gallon fish tank, we recommend upgrading to a 55 or 75 gallon aquarium for your growing pet.

2. The Community Aquarium

Bolivian rams, julii corys, and black skirt phantoms

If one showpiece fish per tank is not your idea of fun, let’s go the opposite direction and fill the 40-gallon tank with many different species. We want to acquire one to three pairs Bolivian rams (Mikrogeophagus alpinus). They are known for their beautiful, trailing fins and will serve as the 3-inch (7.6 cm) centerpiece fish for this community tank. You should ensure that there are plenty of aquarium plants and decorations around to prevent territorial disputes. Then add a school of julii corydoras that will help clean the fish tank by constantly scavenging for leftover food stuck in the substrate. Since you have a medium-sized aquarium to work with, choose a stockier, midlevel schooling fish. Black phantom tetras are a favorite of ours (Hyphessobrycon gigalopterus) due to their strikingly high dorsal feathers.

All of these fish are pretty hardy, live in similar water parameters, and are safe with aquatic plants. These fish eat omnivore food, including frozen bloodworms, pellets and Repashy gel foods. This initial stocking list forms a basic foundation for your 40-gallon community tank. Feel free to spice it up with some of your personal favorites – like a rare pleco, snails, rainbow shark, or some oddball fish.

3. The “Breeding for Profit Tank”

Female albino long fin bristlenose pleco

A 40-gallon tank can house many species, including long fin bristlenose plecos. This catfish runs between 4-5 inches (10-13 cm) long but has giant finnage that takes up more space than normal bristlenose plecos. To accommodate their larger wingspan, they require larger caves. You can breed them in a smaller aquarium, but once they start producing lots of fry, you will have to regularly move the offspring to other fish tanks.

To prevent babies being accidentally sucked up, we use soft sponge filters. Then we condition the adults for breeding by feeding plenty of their favorite foods, like Repashy gel food, sinking wafers, bloodworms, and blanched zucchini. The fry are smaller and prefer to eat live baby brine shrimps, driftwood, crushed flakes, canned green beans, and algae.

Long fin bristlenose plecos come in many varieties – such as albino, green dragon, chocolate, and super red. Start a relationship with your local fish store and find out which types have the highest demand so that you can sell your juvenile plecos to them. For more information, see our article on breeding fish for profit.

4. The African Cichlid Tank

Male and female saulosi cichlids

Most African cichlids require larger fish tanks, but the saulosi cichlid (Chindango saulosi or Pseudotropheus saulosi) is a dwarf mbuna from Lake Malawi that only grows up to 3.5 inches (9 cm). Because of their sexual dimorphism, they look almost like two species. The dominant male is a vibrant blue with dark vertical stripes, while the females have a solid sun-yellow. Subdominant males tend to range from yellow to light blue with faint barring.

We recommend that you get 1-2 males and 4 to 5 females for a 40-gallon aquarium. They require high pH, high GH and KH as well as a high diet rich in vegetation and roughage. To avoid territorial disputes, they need plenty of rocks and hiding places. Saulosi cichlids are very easy to breed, and you may see some of the females holding eggs in their mouths until the fry are free-swimming. The fry can be placed in a separate grow-out aquarium or left to hide in the rockwork while they mature. This dwarf mbuna is a great aquarium option that will rival the vibrant colors of saltwater tanks.


5. The Rare Fish Colony

Trout goodeid

Our last stocking choice was the troutgoodeid (Ilyodon Furcidens), which is a rarer livebearer species from Central America. It looks like a miniature trout measuring 3.5 inches (9 cm). Although they like most livebearers they prefer higher pH levels and higher GH. They also require temperatures lower than 72°F (22°C), which is unusual for them. They aren’t picky eaters, but will happily eat any kind of food, including pellets, flakes, and hair algae, in your aquarium. You could mix them with other fish, but we like experiencing them as a single-species colony to see the unique behaviors that come out when they’re only surrounded by their own kind. Another good usage for a 40-gallon breeder aquarium would be conservation of endangered fish species. If you are interested helping to preserve at-risk fish, search online for the “CARES Preservation Program” to find out more.

These profiles for 40-gallon aquariums should be inspiring to you. There are many other stocking ideas available for both 10-gallon and twenty-gallon tanks. While Aquarium Co-Op does not ship fish, you can see our list of preferred online vendors that sell aquarium animals. Best of luck and enjoy nature daily!