Threadfin rainbowfish tank mates
A 3.5 cm rainbowfish with spectacular trailing fin extensions on males. Peaceful and very slow-moving. Extremely vulnerable to active tank mates that shred the threadfins.
Common mistakeHousing threadfins with cherry barbs or tiger barbs because the tank looked peaceful is how keepers invent shredded fin extensions within days. Those long threads are irresistible targets. Keep calm nano neighbours and a real school — not active barbs for ‘interest.’
Each name below opens a pair check with Threadfin rainbowfish. That check is the decision, not the list itself.
Usually safer companions
Conservative shortlist from this profile. Open a pair page before you buy.
The Threadfin rainbowfish profile lists Chili Rasbora as both safe and a recommended pairing. Chili Rasbora schools in groups of 8 or more, so plan room for the whole group rather than one fish.
The Threadfin rainbowfish profile lists Dwarf Gourami as a recommended pairing. Dwarf Gourami grows bigger than Threadfin rainbowfish (8cm vs 3.5cm). Stock the Threadfin rainbowfish group large enough to outnumber the Dwarf Gourami, or the smaller fish ends up bullied or off food.
The Threadfin rainbowfish profile lists Ember Tetra as both safe and a recommended pairing. Ember Tetra schools in groups of 8 or more, so plan room for the whole group rather than one fish.
The Threadfin rainbowfish profile lists Sparkling Gourami as a recommended pairing. Sparkling Gourami schools in groups of 6 or more, so plan room for the whole group rather than one fish.
Risky or situational
May work with more water, a mature system, or a species-only setup. Read the pair page before you experiment.
Both species defend territory. The pairing needs a long footprint and rockwork or planting that breaks the sightline between two defended spots. Betta is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Threadfin rainbowfish. Run the pair checker before stocking.
Marked risky or situational on the profile. Tank length and group size change the outcome more than a temperament label does.
Marked risky or situational on the profile. Tank length and group size change the outcome more than a temperament label does.
Tiger Barb is flagged as a fin-nipper and Threadfin rainbowfish carries the long-finned risk profile (veil tails, trailing fins). Expect torn fins within days unless the nipper is in a proper group and the long-finned fish has plenty of cover. Tiger Barb is rated semi-aggressive, so expect chasing, fin damage, or display behaviour directed at Threadfin rainbowfish. Run the pair checker before stocking.
Fish to avoid with Threadfin rainbowfish
Predation, aggression, or space rules on this profile. Treat these as poor default mixes.
African Cichlid reaches 15cm and is flagged predatory. Threadfin rainbowfish at 3.5cm is prey-sized for it. African Cichlid needs at least 200L, far above the 60L minimum for Threadfin rainbowfish. The tank that houses one stresses the other. African Cichlid is rated aggressive and Threadfin rainbowfish is rated peaceful. No community-style planning carries that gap.
Angelfish reaches 20cm and is flagged predatory. Threadfin rainbowfish at 3.5cm is prey-sized for it. Angelfish needs at least 150L, far above the 60L minimum for Threadfin rainbowfish. The tank that houses one stresses the other.
Oscar reaches 35cm and is flagged predatory. Threadfin rainbowfish at 3.5cm is prey-sized for it. Oscar needs at least 300L, far above the 60L minimum for Threadfin rainbowfish. The tank that houses one stresses the other. Oscar is rated aggressive and Threadfin rainbowfish is rated peaceful. No community-style planning carries that gap.
Tank size and groups
- Published minimum for Threadfin rainbowfish: 60L. Group minimum 8 (schooling).
- Compatibility changes when the tank is too short for turning, too little for a real school, or too warm for one species and not the other. That is why pair checks include tank context, not only temperament.
- Nearest litre hub to this minimum: 60L hub.
Plan before you buy
Start a pair check with Threadfin rainbowfish, or open a starter plan with the top safer companions in the builder.
Tank hubs: 60L
Related reading
Guides that list other fish with the same trait, so you can plan around the group rather than one row.
- Schooling & group fish →
Plan the group of 8+ before choosing tank mates.
- Beginner-friendly freshwater fish →
Threadfin rainbowfish is on this list. Hardier options for a first stock.
- Peaceful community fish →
Other peaceful species to shortlist beside Threadfin rainbowfish.
Filtration & heating
A 60L minimum tank for Threadfin rainbowfish needs a filter rated for at least 240L/hr turnover and a heater maintaining 25–30°C.
Similar fish (same category)
- Celebes Rainbowfish · min 80L
- Dwarf Neon Rainbowfish · min 100L
- Boesemani Rainbowfish · min 150L
- Turquoise / Lake Kutubu rainbowfish · min 200L
Related (care + temperament)
Threadfin rainbowfish tank mates — quick answers
- What fish can live with Threadfin rainbowfish?
- Usually safer companions on this hub include Chili Rasbora, Dwarf Gourami, Ember Tetra, Sparkling Gourami. Open each pair check before you buy — the list is a shortlist, not a guarantee.
- What tank mates should you avoid with Threadfin rainbowfish?
- Avoid African Cichlid, Angelfish, Oscar based on size, temperament, or predation risk on this profile.
- What size tank do Threadfin rainbowfish need for a community?
- 60L is the planning floor for adult swimming space and bioload. A 73L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.