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

Because of its dimensions (91 x 46 cm x 41cm) the 40-gallon breeder tank is very popular, it measures 36 inches in length, 18 inches width, and 16 inches height. 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. Continue reading to discover our top 5 fish stocking strategies for a 40-gallon breeding tank.

1. The Flowerhorn Tank

Flowerhorn cichlid

This New World cichlid hybrid is famous for its colorful patterns and large nuchal, which grows on males’ heads. Flower horn fish are especially valued in certain Asian cultures because they are thought to bring good luck and prosperity. While flowerhorns are quite playful and personable towards their human owners, they can be fairly aggressive toward other smaller animals in their territory. We suggest keeping one in the 40-gallon aquarium and not sharing it with other tank mates. When it gets bigger, your wet pet will eat lots of food and therefore need more water changes to keep the water clean. After enjoying a few years in the 40-gallon breeding tank, we recommend that your pet be upgraded to a 55 gallon or 75 gallon aquarium to keep up with its growing needs.

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. First, we will be getting one to three pairs Bolivian-rams (Mikrogeophagus altaspinosus). They are well-known for their beautiful, trailing fins. They will be the 3-inch (7.6 cm), centerpiece fish of this community tank. To minimize territorial disputes, make sure to provide plenty of aquarium plants and decorations to block line of sight. A school of julii Corydoras will be added to clean your fish tank. They will eat any food left behind in the substrate. You have a medium-sized aquarium so choose a stockier fish that is more schooling. Because of their strikingly large dorsal fins, we love black phantom Tetras (Hyphessobrycon Megalopterus).

These fish are all quite hardy and can live in the same water conditions as other aquatic plants. These fish eat a similar diet of omnivores such as frozen bloodworms pellets and Repashy Gel food. This stocking list is a good starting point for your 40-gallon community aquarium. You can spice it up by adding your own favorites, such as rare plecos, snails, rainbow sharks, or other oddball fish.

3. The “Breeding for Profit Tank”

Female albino long fin bristlenose pleco

There are many species you can breed in a 40-gallon breeding aquarium. This catfish can grow to 4-5 inches (10-13cm) in length, but its finnage is much larger than that of normal bristlenose plecos. To accommodate their larger wingspan, they require larger caves. While you can keep them in a small aquarium, they will start to produce a lot of fry and you will need to move them regularly to other fish tanks.

We use sponge filters for filtration to prevent the babies being taken in by mistake. Then we condition the adults for breeding by feeding plenty of their favorite foods, like Repashy gel food, sinking wafers, bloodworms, and blanched zucchini. Fry have smaller mouths than adults and love to eat driftwood, baby brine shrimp, crushed flakes and canned green beans.

There are many kinds of long-fin bristlenose plecos – including chocolate, super red and green dragon. You can start a relationship to your local fish store to discover which species are in greatest demand so you can sell your 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 need larger fish tanks. However, the saulosi (Chindango saulosi/Pseudotropheus Saulosi) is a dwarf lake Malawian mbuna that can grow up to 3.5inches (9 cm). Because of their sexual dimorphism, they look almost like two species. The dominant male is a vivid blue with dark, vertical striping, whereas the females are a solid sunshine yellow. Subdominant males can range from yellow to lightblue with slight 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. They need lots of rocks, hiding places and other obstacles to avoid territorial disputes. 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. You have two options: either move the fry to a separate tank, or allow them to stay in the rockwork until their bodies are strong enough for independent living. The dwarf mbuna is an enjoyable and fun aquarium design that can rival the bright colors of saltwater tank tanks.

5. The Rare Fish Colony

Trout goodeid

For our last stocking choice, we chose the trout goodeid (Ilyodon furcidens), a rarer type of livebearer from Central America that looks like a 3.5-inch (9 cm) miniature trout. They are similar to most livebearers and prefer higher pH and greater GH. However, their preference is for temperatures below 72 degrees Fahrenheit (22 degrees Celsius). They will happily eat pellets, flakes, and even hair algae from your planted aquarium. They can be mixed with other fish but we prefer them to live in a single species colony. We love seeing their unique behaviors when they are not surrounded by any other species. Another good usage for a 40-gallon breeder aquarium would be conservation of endangered fish species. To learn more about preserving at-risk fish species, you can search the internet for “CARES Preservation Program”.

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. Aquarium Co-Op does NOT ship fish. You can however see our list for preferred online sellers that sell aquarium animals. All the best and have a wonderful time in nature!