Can Cardinal Tetra Live With Harlequin Rasbora?
Yes, cardinal tetras and harlequin rasboras thrive together in 15 gallons or larger, with overlapping soft-water preferences and matching care requirements.
Why
- Cardinal tetras reach 2 inches and harlequin rasboras grow to 2 inches as well.
- Both species school in the middle water column, creating a combined display of coordinated movement.
- Temperature overlap spans 73-81F, matching both species' preferred ranges.
- Both prefer slightly acidic to neutral water in the 6-7 pH range.
- Neither species nips fins or displays aggression toward tankmates.
What could go wrong
Both species need schools of 8 or more, so a 15-gallon tank fills up fast if you want a proper group of each.
Gear for a shared tank
Sized for the 15 gallon minimum this pairing needs. Affiliate links — we earn a small commission if you buy through them.
AquaClear 30 Power Filter
Oversized filtration is what lets you stock two species together without water quality crashing. Rated for a tank slightly larger than the 15 gallon minimum.
Eheim Jager 150W Thermostat Heater
Holds a steady temperature inside the 73-81°F window both species need.
API Freshwater Master Test Kit
Keep ammonia, nitrite, and nitrate in check. Two-species tanks have more bioload and less margin for error than single-species setups.
Related compatibility questions
Keep reading
Planning a community tank?
Check compatibility for any two freshwater species before you buy. Stop guessing, stop returning fish.
Open the compatibility chart →