Rasbora

Rasbora key facts

Care level

Beginner-friendly

Lifespan

3-5 years

Size

2-5cm

Diet

Pellets, frozen food

Tank

45cm+ for schooling

Schooling

10+ for beautiful schooling display

Water Quality

Soft, slightly acidic water best

Temperature

24-28°C

Notes

Small size — avoid keeping with large fish

About Rasbora

Rasboras are a group of small fish from the carp family found across Southeast Asia, including Thailand, Malaysia, and Indonesia, and have been a staple of the aquarium hobby for decades. Among the most beloved species are the Lambchop Rasbora (Trigonostigma espei), with its warm orange body and distinctive black patch, and the Harlequin Rasbora (Trigonostigma heteromorpha), recognized by its striking triangular marking. Though small at 2–5 cm, a school of ten or more moving in unison brings remarkable energy and visual beauty to any aquarium. Their peaceful nature makes them ideal companions for other calm, similarly sized fish, allowing them to serve as either a centerpiece species or a graceful supporting cast in a community tank. They are particularly well-suited to planted aquariums, where their vivid colors contrast beautifully against lush green vegetation. With a lifespan of three to five years and straightforward care requirements, Rasboras offer lasting enjoyment for fishkeepers of all experience levels.

7 things to know before welcoming a Rasbora

1. 1Keep Them in Groups

   Rasboras are schooling fish and thrive best in groups of six or more of the same species. Keeping them alone or in small numbers can cause stress, leading to timid behavior and faded coloration. Aim for a larger group to enjoy their natural schooling behavior.

2. 2Ideal for Planted Tanks

   Rasboras are exceptionally well-suited for planted aquariums, where their vibrant colors stand out beautifully against lush greenery. The hiding spots created by plants help the fish feel secure and display more natural behavior. They won't damage plants, making them ideal for aquascape setups.

3. 3Prefer Soft, Slightly Acidic Water

   Most rasboras prefer soft, slightly acidic to neutral water (pH 6.0–7.5), similar to their native Southeast Asian rivers. Matching these conditions enhances their coloration and breeding readiness. Regular water quality checks are important, as unsuitable parameters can cause stress and disease.

4. 4Optimal Temperature: 25–28°C

   As tropical fish, rasboras require a stable water temperature of 25–28°C. Temperatures dropping below 20°C weaken their immune system and increase susceptibility to diseases like ich. Always use a reliable heater and thermometer to maintain consistent conditions year-round.

5. 5Choosing Tank Mates Carefully

   Rasboras are peaceful and generally compatible with many small fish, but they may be eaten by larger, predatory species. Conversely, aggressive or large fish like angelfish can stress rasboras. Stick to similarly sized, peaceful species when choosing tank mates.

Frequently asked questions about Rasbora

Q.Are Rasboras easy to keep for beginners?

A.Rasboras are hardy and adaptable, making them one of the most recommended starter fish in the tropical aquarium hobby. As long as you maintain stable water parameters — consistent pH and temperature — they are relatively easy to keep healthy. Introducing at least six fish at once helps reduce stress and encourages natural schooling behavior from the start.

Useful tools for Rasbora care

Learn more about Rasbora in the encyclopedia

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