Description

Species Background
Rummy nose tetras originate from the Amazon and Orinoco river systems, where they inhabit warm, stable tributaries with consistent water chemistry and high oxygen levels. In their natural environment they move continuously in coordinated schools. The red coloration on the head functions as a visual health indicator and fades rapidly when conditions are unstable.

Behavior and Temperament
Peaceful and highly social. This is a true schooling species that relies on group cohesion for security and normal behavior. When kept in appropriate numbers they display tight, synchronized schooling and constant midwater movement. When kept in small groups they become pale, stressed, and prone to losses.

Adult Size
Adults typically reach 1.75 to 2 inches.

Water Parameters
These ranges reflect modern captive husbandry and long term aquarium success. Stability is more important than exact targets.

Temperature: 75–82°F
pH: 5.5–7.2
GH: 1–8 dGH
KH: 0–4 dKH

Tank raised individuals tolerate the upper end of these ranges well when water conditions remain stable.

Diet
Omnivorous micro feeders. Accept fine flakes, micro pellets, and frozen or live foods such as baby brine shrimp, daphnia, and cyclops. A varied diet supports stronger coloration and sustained activity.

Tank Requirements
Minimum tank size: 20 gallons
Strongly recommended group size: 8 or more
Planted layout with open swimming lanes
Consistent filtration and good oxygenation

Why They’re Popular
Rummy nose tetras are popular because they display some of the tightest schooling behavior among small tetras and visibly reflect aquarium conditions through their coloration. When conditions are right, they move as a single coordinated group and add constant motion to planted community aquariums.