Can Chili rasbora live with Harlequin rasbora?

Temperature. Chili rasbora does best at 25–28 °C (77–82 °F) and Harlequin rasbora at 22–25 °C (72–77 °F). They share only 25 °C, which leaves almost no margin for a heater swing.

Water. Their pH ranges overlap at 6–7.

Temperament and size. Chili rasbora is peaceful and grows to 2 cm; Harlequin rasbora is peaceful and grows to 4.5 cm. Both use the mid of the tank, so give them room and cover.

Tank size and groups. Plan on at least 15 US gallons, the larger of the two cautious minimums. Keep Chili rasbora in a group of 8+. Keep Harlequin rasbora in a group of 8+. A starter mix of 8 Chili rasbora and 8 Harlequin rasbora in 15 gallons uses about 90% of the tank’s bioload capacity under our rules and grades A.

Keeping them together

• Feeding: both feed in open water. Feed small amounts two or three times a day so the slower eater gets its share.
• Aquascape: both are calmer with cover. Plants and floating cover make shy fish come out more, not less.
• Group size: a full group is not optional. A schooling fish kept in too small a group is stressed and more likely to nip or hide.
• Adding them: add the calmer species first and let it settle for a week or two before adding the other, and only once your tank has cycled.

Better matches for Chili rasbora

These pass every rule with Chili rasbora: Cardinal tetra · Cherry barb · Guppy · Molly · African dwarf frog · Amano shrimp · Assassin snail · Banjo catfish.

Open this pair in the checker Add your other fish to grade the whole tank.

Quick facts

Data from the Species Ledger, checked November 9, 2026, with at least two sources per species. Cautious community guidelines, not guarantees: individual fish vary. Not veterinary advice. Disagree? Tell us.