5 Best Fish Tank Ideas for a 55-Gallon Aquarium

55-gallon fish tanks are one of our favorite sizes because the 48" length x 13" width x 21" height (122 x 33 x 53 cm) dimensions give you a lot of options to play with. Everyone has different preferences for the types of aquariums they like to keep, so to help inspire you, we have put together our top 5 freshwater setups that you should try.

1. The Planted Livebearer Tank

Fancy mollies

Livebearers are fish that bear live young instead of eggs, and they are often prominently featured at pet stores because of their vivid colors and high energy level. Therefore, the purpose of a livebearer tank is to feature tons of color, active movement, and baby fish. You can generally mix guppies, platies, and mollies together, but if you add the larger swordtails, expect to end up with lots of fat swordtails and fewer guppy babies. Since livebearers breed very easily, expect to feed lots of little foods for the fry and do frequent water changes to clean up their waste.

To help consume all the toxic nitrogen chemicals produced by fish poop, add lots of fast-growing plants like water sprite and Pogostemon stellatus ‘octopus’. The dense foliage will also provide shelter and help increase the survival rate of the offspring. Plus, livebearers do best in hard water with higher pH and GH. If you have low pH, consider adding crushed coral in your substrate or filter media bags. If you have low GH, dose mineral supplements like Wonder Shell and Seachem Equilibrium to help keep your fish and plants healthy. A livebearer aquarium is always such a crowd pleaser that continually evolves as the fish babies and plants grow, so we always recommend them to our customers.

2. The African Cichlid Tank

Yellow lab, purple acei, and red zebra cichlids

A 55-gallon aquarium is doable for an entry-level African cichlid tank, so we picked our favorite cookie cutter setup that combines three strategic species that look amazing together.

• Yellow lab cichlid (Labidochromis caeruleus) – bright yellow fish with black markings on fins
• Purple acei cichlid (Pseudotropheus ‘acei’) —purple fish that is a little bigger and contrasts well with the yellow lab cichlid
• Red zebra cichlid (Maylandia estherae) – fish that comes in orange to cherry red colors

Since African cichlids can be territorial with each other, crowding the tank with more cichlids helps bring down the aggression level and eliminate targeting by the dominant fish. We recommend that you start with up to six fish of each species. Ideally, they should all be the same size and added to the tank within the same month to minimize territorial disputes. Some hobbyists like to start with 12 juveniles of each species and then rehome some of the males as they get bigger so that they end up with an ideal ratio of two males and four females for each group.  An African cichlid aquarium is truly one of the closest setups to a saltwater tank with all the bright colors but usually at a lower cost.

3. The Tetra Community Tank

Red phantom, glowlight, and rummynose tetras

The classic community aquarium often has at least one school of tetras in it, but what if you dedicated the whole tank to tetras? The great thing about tetras is that almost any of them can go together — such as neon, rummy nose, black skirt, emperor, and ember tetras. Tetras are relatively inexpensive and usually small in size, so this setup allows you to continually visit your local fish store and slowly add to your collection over time. Plus, you can get your family involved by bringing them along and asking them to choose their favorite tetra to take home. Spice up the rest of the tank with some aquarium plants, decorations, and bottom dwellers like cory catfish and kuhli loaches. Then sit back and enjoy a beautiful display tank with a multitude of different species swimming together in harmony.

4. The Angelfish Aquarium

Silver angelfish

The quintessential angelfish tank usually entails live aquarium plants with one school of angelfish. This school can consist of 6–10 silver, black, koi, or other type of angel. As a point of contrast, add a second schooling fish that is smaller in size. Neon tetras and other similar-sized fish are too small and will likely end up as food for fully grown angelfish. Instead, pick schooling fish that are around 2 inches (5 cm) or larger, like lemon tetras and cherry barbs.

One of our favorite things is turn off all the lights except the aquarium light and watch the angelfish slowly swim back and forth while the schooling nano fish gracefully evade the angels. The tranquil movement of the two groups is mesmerizing to watch, especially after a long day of work or school.

5. The Barb Tank

Gold barbs

If a mellow tank is not your vibe, the opposite would be a “Thunderdome” of barbs. Barbs are often shunned because they are so fast and semi-aggressive, but they are very fun if you’ve never kept them before. Just drop in a cube of frozen bloodworms and watch them go wild. Like African cichlids, they tend to do best when kept in large groups of their own kind. One idea is to make a tank full of tiger barbs, but mix together all the different color variations — such as regular, albino, green, GloFish, and longfin. Another idea is to keep different barbs in your 55-gallon aquarium — like cherry, tiger, rosy, gold, and checker barbs. Since barbs are schooling fish, get at least 6–10 fish per species.

Hopefully, this article has sparked your interest in 55-gallon fish tanks. People rarely keep the same setup forever, so if you find yourself losing interest after 2–3 years, rehome your fish to other hobbyists who will love them as you did and then switch to another kind of setup that you’ve never tried out before. Check out our preferred online vendors to see the latest fish they have in stock.