Small aquariums are cute and easy to set up, but choosing the right tank mates for them is tricky. The majority of beginners mix random fish together and hope everything will work. However, real fish have different personalities, space needs, and behavior: some of them are peaceful, while others are fast swimmers and may become aggressive if the tank is too small.
The good thing is, there are literally scores of varieties of fish that can live quite happily in smaller tanks when chosen correctly. This guide will help you understand which fish do well together, what to avoid, and how to keep a peaceful community tank without fights or stress.
1. Understanding “Small Aquarium” Firstly
A small aquarium usually means anything between 20 to 60 liters. These tanks require fish that:
• Remain small throughout their lives.
• Do not contribute to excessive garbage generation
• Not in need of large territories
• Peaceful and schooling fish
If a fish grows above 6–7 cm, it usually becomes uncomfortable in small tanks.
2. Best Peaceful Tankmates for Small Aquariums
Star 1. Neon Tetras
Neon tetras are one of the most popular small fishes due to their good-looking appearance and peaceful behavior.
• Keep in groups of at least 8–10
• They like planted and tranquil tanks
Mix well with most small peaceful species
Blue and red colors also make the tank bright.
2. Ember Tetras
Ember tetras are much smaller than neon tetras and, therefore ideal for very small tanks.
• Very peaceful
• Dazzlingly bright orange in colour
• Thrive well with shrimp and snails
They are also low maintenance and perfect for beginners.
3. ⭐ Guppies (best in a male-only tank)
The reasons for choosing guppies are because they are colorful, active, and breed easily.
They are safer for community tanks because females contribute to overpopulation.
• Amicable
• Add plenty of colour
• Work well with tetras and mollies
Just don’t mix them with fin-nipping fish.
4. Corydoras Small Cory Cats
Corydoras are bottom feeders that help clean up food from the substrate.
Best for small tanks:
Pygmy corydoras
• Panda corydoras
They remain docile and stir up the bottom.
5. ⭐ Harlequin Rasboras
These fishes remain small and look beautiful in shoals.
• Hardy
• Serene
• Low maintenance
They also do not bother the other tankmates.
⭐ 6. Dwarf Gourami (Only One!)
One dwarf gourami could be enough to steal the show as a centerpiece fish.
• Docile if left alone
• Likes plants
• Peaceful in community, gets along with: Tetras, mollies, and rasboras
Never keep two males in a small tank, as they will be aggressive to each other.
⭐7. Snails (Nerite or Mystery Snails)
Snails are good for cleaning.
Algae consumption by
• Don’t disturb fish
• Low maintenance
Nerite snails are especially good because they don’t breed in freshwater.
8. ⭐ Shrimps - Cherry or Amano Shrimp
Shrimps add vitality and motion in the tank.
• Alga clean
• Consume left-over food
• Safe for peaceful fish
Avoid having shrimps with a predator or any large fish that may attack them.
Conclusion
Small aquariums can be peaceful, beautiful, and full of life if you choose the right tank mates. The key is selecting species that stay small, stay calm, and enjoy schooling. With the right mix of fish, plants, and a good filter, your small tank can look like a mini underwater world full of color and activity.
A peaceful tank is not about size—it’s about balance.