Small fish tanks between 20-75 litres are among the most popular sizes in the freshwater aquarium hobby because they take up less space and are more affordable. Despite their size limitations, these nano tanks offer endless possibilities for species, layouts, and purposes. Here are five inspiring ideas to help you plan your next small aquarium.
Nano Aquascape
A small aquarium is an excellent starting point for aquascaping, which involves creating a stunning underwater landscape with a mix of hardscape materials, live plants, and animals. Begin by looking online for aquascaping inspiration, sketching a design, and making a list of needed materials. Arrange the rocks and driftwood in the empty tank to form the structure of your design, using consistent materials for a cohesive look.
Next, plant your greenery, placing smaller plants in the front and taller ones in the back for visibility. Choose fish that complement the aquascape without overwhelming it. Rasboras Galaxy, with their vibrant fins and dotted bodies, or tiny chili rasboras, with their striking red hue, make great choices. For the lower levels, consider nano bottom dwellers like rosy loaches or habrosus corydoras. To keep the tank clean, add algae eaters such as amano shrimp, otocinclus catfish, or nerite snails. This mix will add dynamic activity to your planted aquarium.
Centerpiece Tank
In contrast to a nano aquascape, this setup features a single standout fish as the focal point. Ideal for a tank holding 20-75 litres, choose a species that grows to a maximum of 8 cm. The decorations and plants should be sparse to avoid overshadowing the centerpiece fish.
A betta fish is a popular choice due to its striking colours and hardy nature. A single betta can thrive in a 20-litre tank with a gentle sponge filter and heater. For a more sociable tank, consider increasing the size to 75 litres, adding taller plants to provide hiding spots, and pairing the betta with peaceful schooling fish that stay out of its way.
Alternatively, smaller gouramis like honey gouramis or sparkling gouramis can serve as excellent centerpiece fish. Their vibrant colours and bold personalities make them stand out, and they can coexist peacefully with small schooling fish such as tetras, danios, and cory catfish.
Shrimp Tank
Dwarf shrimp are best kept away from betta fish and gouramis, as most fish view them as food. A dedicated 40-75 litre tank is ideal for a shrimp-only setup or a breeding project. Neocaridina shrimp, or cherry shrimp, are great for beginners due to their resilience and variety of colours.
Prepare a mature, seasoned aquarium with plenty of microfauna and algae for grazing. This ensures a stable environment with healthy, growing plants and a well-developed biofilm. Shrimp thrive in slightly higher pH and GH levels, which help them develop strong exoskeletons. For more detailed information on shrimp care, refer to our comprehensive guide.
Shell Dweller Tank
African cichlids like Neolamprologus multifasciatus and N. similis are perfect for a 75-litre species-only tank. These shell dwellers are fascinating due to their unique breeding behaviours. Set up the aquarium with a sandy substrate, tall rocks to block sightlines, and multiple large snail shells for hiding and spawning.
These busy little fish will rearrange their shells and sand to create the perfect environment. Feed them a varied diet of crushed flakes, Repashy gel food, nano pellets, baby brine shrimp, and frozen bloodworms. With proper care, you'll soon see tiny fry exploring the tank. Learn more about shell dwellers in our detailed care guide.
Breeding Pair Setup
For those looking for a more challenging breeding project, consider the Apistogramma genus, which includes around 100 species of colourful South American dwarf cichlids. A pair of apistos can breed in a 60-75 litre tank if given the right conditions.
Start with a group of young apistos to allow natural pairing, then rehome the extras. Set up the breeding tank with caves for spawning and plenty of plants for comfort. Maintain high water quality and provide ample food to encourage breeding. With the right setup, you'll soon see parents guarding their eggs and guiding their fry.
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