Rummy-nose tetras are silver torpedoes with a glowing red face and a boldly striped tail, famous for schooling more tightly than almost any other aquarium fish.
A group moving as one is a genuine spectacle.
They carry a built-in diagnostic: the red nose drains to washed-out pink when the fish are stressed or the water deteriorates, making the school a live water-quality gauge.
Housing
Keep a school of ten or more in a mature, cycled aquarium of 75 litres (20 gallons) or larger — bigger groups in longer tanks school more impressively.
Provide open swimming length with planted flanks.
Hold the temperature at 24-28C.
They come from soft, acidic blackwater, and while tank-bred stock adapts to moderately hard water, what they cannot forgive is instability: drift and spikes show in the noses immediately.
Diet
Offer fine flake or micro-pellets as the staple, with regular frozen or live treats such as daphnia, cyclops, baby brine shrimp, and chopped bloodworm.
Their mouths are small, so size food accordingly.
Feed once or twice daily in small amounts.
A well-fed, settled school shows saturated red noses at every feed.
Health
Rummy-noses are not delicate once settled, but they ship poorly and resent new, unstable tanks; add them to mature aquariums only and quarantine first.
Losses in the first fortnight usually mean the tank, not the fish, was not ready.
After that, standard tetra care applies: watch for ich after temperature dips and keep nitrate low with steady weekly water changes.
Faded noses are the early-warning sign — investigate before anything else goes wrong.
Temperament
Completely peaceful, rummy-noses spend the day cruising in formation through the lower midwater.
The tighter the school, the more secure the fish — small groups huddle and hide instead.
They are ideal companions for other gentle blackwater species: cardinal tetras, corydoras, dwarf cichlids, and pencilfish.
Nothing about them threatens shrimp colonies beyond the odd newborn.
A good fit for
Keepers who want true, dramatic schooling behaviour
Mature planted aquariums with stable parameters
Communities with dwarf cichlids and corydoras
Aquarists who like visible feedback on water quality
Common mistakes to avoid
Adding them to brand-new, unstable tanks
Groups under 8-10 that huddle rather than school
Temperature and parameter swings — noses fade fast
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate