Rummy-nose tetra

1) Where they come from

Rummy-nose tetras come from the Amazon basin—mainly blackwater tributaries with tea-colored water, leaf litter, and soft, acidic conditions. That “red nose” look is basically their mood ring: if they’re stressed or the water’s off, it fades fast.

2) Setting up their tank

These aren’t “tough it out” tetras. They do best in a stable, mature tank. I’ve had the best luck once a tank is fully cycled and has been running a while—rummy-noses punish new setups.

• Tank size: 20 gallons long is a great starting point, bigger is even easier
• Group size: 10–15+ makes them way more confident (and the school looks amazing)
• Temp: warm side, roughly 78–82°F (they sulk in cooler water)
• pH/hardness: they’ll adapt, but soft to moderately soft water keeps them looking and acting their best
• Filtration: steady flow is fine, just don’t blast them like a river tank
• Lighting: moderate; plants help them relax and bring out color

A sandy or fine gravel substrate works. Add plants (stems, crypts, floating plants), a few bits of wood, and some leaf litter if you like the look. They don’t need caves, but they love visual cover and open swimming lanes.

3) What to feed them

Rummy-noses are easy to feed once they’re settled, but they’re small-mouthed and a little shy the first week or two. Think tiny foods, frequent small portions, and variety.

• Staple: quality micro pellets or fine flake (crush it if needed)
• Frozen: baby brine shrimp, daphnia, cyclops, finely chopped bloodworms
• Live (if you can): baby brine shrimp and daphnia get them fired up fast
• Extras: occasional veggie-based flake for balance (they’re not big plant eaters, but variety helps)

4) Behavior and tankmates

A healthy school is nonstop motion—tight formation, coordinated turns, and that classic black-and-white tail flashing. In small groups they get skittish and scatter; in bigger groups they settle down and act “right.”

• Great tankmates: other peaceful tetras, pencilfish, rasboras, small peaceful barbs, Corydoras, otos, peaceful dwarf cichlids (like rams/apistos in the right setup)
• Usually fine: calm gouramis, small plecos that aren’t jerks
• Skip: fin nippers, big/fast feeders that hog all the food, anything that sees them as snacks (large cichlids, big catfish), or super boisterous fish that keep them pinned in corners

5) Breeding tips (if you want to try)

Breeding them is doable, but it’s a project—more like a weekend science experiment than “oops, free babies.” They scatter eggs and will absolutely eat them if given the chance.

• Use a separate breeding tank (10–20g) with a sponge filter and gentle aeration
• Soft, acidic water helps a lot; warmer temps also encourage spawning
• Give them something to spawn over/into: a mesh, marbles, or a thick clump of fine plants (Java moss works)
• Condition adults on live/frozen foods for 1–2 weeks
• Move a pair or small group in the evening; spawning often happens early morning
• Pull adults right after you see eggs (or as soon as spawning is done)

Fry are tiny. Start with infusoria or a commercial fry food for egglayers, then move to baby brine shrimp once they can take it. Clean water matters a lot here—gentle, frequent small water changes beat big ones.

6) Common problems to watch for

Most rummy-nose “issues” are really tank issues. They’re sensitive fish, and they broadcast stress loudly with color loss and weird schooling.

• Pale red noses: usually stress, temperature too low, or water quality slipping (check ammonia/nitrite first, then nitrates)
• Hiding and not eating: new tank jitters, too small a group, or aggressive tankmates
• Ich outbreaks: they can be ich magnets after shipping stress—quarantine new fish if you can
• Rapid breathing at the surface: low oxygen, high temp with not enough surface agitation, or gill irritation
• Random losses in “new” tanks: unstable cycle or big parameter swings after water changes