Harlequin rasbora Tank Mates

Short answer: the best harlequin rasbora tank mates are Betta fish, Dwarf gourami, Guppy, Bristlenose pleco, Molly, Neon tetra. Harlequin rasboras need 70–82 °F (21–28 °C), pH 5–7.5 and at least 20 gallons. Keep them in a group of 6 or more.

Trigonostigma heteromorpha · rated against 71 species · check your own combination

Harlequin rasbora care at a glance

Adult size2.0 in (5 cm)
Minimum tank20 US gallons
Temperature70–82 °F (21–28 °C)
pH5–7.5
TemperamentPeaceful
Swims inMiddle
Group sizeGroups of 6+
Care levelEasy

Sources: Seriously Fish · FishBase. Last reviewed 2026-11-04.

gallon tank

✅ Compatible tank mates (50)

⚠️ Possible with caution (12)

❌ Not recommended (9)

How many harlequin rasboras per tank?

20 gal 29 gal 40 gal 55 gal 75 gal — see what else fits with our stocking calculator.

FAQ

What fish can live with harlequin rasboras?

Good matches include Betta fish, Dwarf gourami, Guppy, Bristlenose pleco, Molly, Neon tetra. They share a temperature range with harlequin rasboras (70–82 °F (21–28 °C)), are a similar temperament, and are not big enough to eat each other or nip fins.

What fish should not live with harlequin rasboras?

Avoid Fancy goldfish, Oscar, Pea puffer, White cloud mountain minnow, Electric yellow cichlid, Paradise fish.

What size tank do harlequin rasboras need?

We recommend at least 20 US gallons for a group of 6 harlequin rasboras, more if you add tank mates.

Can harlequin rasboras live alone?

No. Harlequin rasboras are social and should be kept in groups of at least 6.

Note: Compatibility depends on individual temperament, tank size, decor and how fish are introduced. Our verdicts use conservative rules applied to published care data (see methodology). They are guidance, not a guarantee. Quarantine new fish and watch for chasing, torn fins or hiding.