Rummy-nose tetra

Where they come from

Rummy-nose tetras come from the Amazon basin, mostly blackwater tributaries where the water is tea-colored from leaves and wood. Think soft, acidic water, dim light, lots of submerged roots, and a gentle current. That background explains a lot about why they look and act the way they do in our tanks.

Setting up their tank

If you want rummies to look their best, give them room to school and stable water. I have had the best luck in longer tanks with open swimming space in the middle and plants and wood pushed to the sides.

• Tank size: 20 gallons long works, but 29 gallons and up makes their schooling behavior way more satisfying
• Group size: 10-12 is where they really click, 6 is the bare minimum
• Flow and oxygen: they appreciate a bit of current and high oxygen, so a decent filter and surface movement help
• Lighting: not too bright, or at least break it up with floaters or tall plants
• Decor: driftwood, leaf litter (optional), fine gravel or sand, and plants around the edges

They are a little more sensitive than a lot of other tetras, so I would not toss them into a brand new setup. Let the tank mature, keep nitrates low, and avoid big temperature or pH swings. Soft to moderately soft water tends to make life easier with them, but the real secret is consistency.

What to feed them

They are easy to feed once they settle in. In the wild they pick at tiny bugs and micro-crustaceans, so think small foods that drift in the water column.

• Daily staples: quality micro pellets, small flakes, crushed flake for younger/smaller fish
• Best color and condition boosters: frozen daphnia, cyclops, baby brine shrimp, and finely chopped bloodworms
• For picky new arrivals: live baby brine shrimp or live daphnia gets them eating fast

How they behave and who they get along with

Rummy-nose tetras are classic tight schoolers. In a good-sized group they move like one fish, and it never gets old. If the group is too small, they get shy and scatter, and they also look washed out more often.

They are peaceful and spend most of their time midwater. They do not usually nip fins, but stressed fish can get a little twitchy, so focus on giving them a calm environment and enough of their own kind.

• Great tankmates: other calm tetras, pencilfish, corydoras, small rasboras, otocinclus, kuhli loaches
• Works with care: angelfish only if they are small and the tank is roomy (adult angels may view them as snacks)
• Avoid: aggressive barbs, big cichlids, fin-nippers, anything large enough to eat them

Breeding tips

Breeding rummy-nose tetras is doable, but it is fussier than breeding something like neon tetras. The eggs and fry do better in very clean, soft, acidic water, and the adults will absolutely eat the eggs if you give them a chance.

• Use a separate breeding tank (10-20 gallons) with a sponge filter and gentle aeration
• Keep lighting dim, and use a spawning mop or fine-leaved plants so eggs can fall out of reach
• Condition adults with live/frozen foods for a week or two
• Many people have better luck with very soft water (often RO mixed) and a lower pH
• Pull the adults right after spawning, or use a mesh/egg crate barrier

Common problems to watch for

Most rummy-nose issues trace back to stress and water swings. They are not fragile once settled, but they do not forgive sloppy maintenance the way hardier fish might.

• Faded red nose: often water quality, temperature drop, bullying, or too small a group
• Losses right after purchase: shipping stress plus moving into an immature tank or big parameter swing
• Ich outbreaks: they can be one of the first fish to show spots after a stressful event
• Wasting/skinny fish: internal parasites are not rare in new stock, especially if appetite is weird

If you keep them in a stable, clean tank with a real school and decent oxygen, they reward you with nonstop synchronized swimming and that bright red face. They are one of those fish that quietly tells you how your tank is doing.