Can Blue Emperor Tetra Live With Molly?
Yes, blue emperor tetras and mollies coexist peacefully in 20 gallons or larger, with tetras schooling in the middle and mollies using the upper water levels.
Why
- Blue emperor tetras are small mid-water schooling fish at 1.5-2 inches, while mollies grow much larger at 4-5 inches but are peaceful upper-level swimmers that ignore smaller fish.
- Mollies are active swimmers but are not predators and pose no threat to properly-schooled blue emperor tetras of 6 or more individuals.
- Temperature overlap of 73-81 degrees Fahrenheit suits both species, with blue emperor tetras preferring the cooler end around 76-78 degrees.
- Both species tolerate the pH overlap of 7.0-7.5, though mollies prefer harder, more alkaline water at pH 7.5-8.5 if kept long-term without tetras.
- A 20-gallon minimum provides enough space for blue emperor tetras to school comfortably while giving mollies room to swim without crowding.
What could go wrong
Mollies are enthusiastic surface feeders that may outcompete blue emperor tetras for food if feeding is not managed, so use sinking pellets for tetras and floating food for mollies to ensure all fish eat.
Gear for a shared tank
Sized for the 20 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 20 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
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