CheckMyFishTankThreadfin Rainbowfish care
Iriatherina werneri · Freshwater · Intermediate level care
A delicate rainbowfish with long, wispy fins that needs gentle company.
Feeding
Twice a day. A small pinch they finish in about 2 minutes. Micro pellets, baby brine shrimp, crushed flakes.
Has long fins that fin nippers target.
Good tank mates
Fish that pass every check with Threadfin Rainbowfish in a 40 gallon tank: same water, overlapping temperature, nobody gets eaten and no bullies.
Do not mix with
- Silver Dollar: Silver Dollar grows big enough to eat Threadfin Rainbowfish.
- Tinfoil Barb: Tinfoil Barb grows big enough to eat Threadfin Rainbowfish.
- Angelfish: Angelfish grows big enough to eat Threadfin Rainbowfish.
- Discus: Discus and Threadfin Rainbowfish need different water temperatures.
- Convict Cichlid: Convict Cichlid grows big enough to eat Threadfin Rainbowfish.
- Oscar: Oscar grows big enough to eat Threadfin Rainbowfish.
- Jack Dempsey: Jack Dempsey grows big enough to eat Threadfin Rainbowfish.
- Firemouth Cichlid: Firemouth Cichlid grows big enough to eat Threadfin Rainbowfish.
Questions
What size tank does a Threadfin Rainbowfish need?
At least 20 gallons for a group of 6. Adults grow to about 2 inches, so plan for the adult size, not the size at the store.
What temperature does a Threadfin Rainbowfish like?
72 to 80 degrees Fahrenheit, with a pH of about 6.5 to 7.5. A steady temperature matters more than hitting one exact number.
How many Threadfin Rainbowfish should I keep together?
Keep 6 or more. They feel safe in a group and show better color and behavior.
What do Threadfin Rainbowfish eat?
Micro pellets, baby brine shrimp, crushed flakes. Feed twice a day: a small pinch they finish in about 2 minutes.
Sources
Checked against these sources on 2026-11-10. When sources disagree we use the safer number.