The rummy-nose tetra is a long-time favorite in the hobby because of its unique colors and tight schooling behavior, which is why it ranks in the top 20 fish sold at our retail fish store. This outgoing fish gets its common name comes from the reddish flush on its face, and there’s nothing like seeing a large group of gorgeous redheads darting back and forth amidst an emerald forest of live aquarium plants. Learn more about this dazzling tetra and how to best bring out its crimson colors.

What are Rummy Nose Tetras?

These 2-inch (5 cm) South American characids have a torpedo-shaped profile typical of tetras. While the body is shiny and silvery, the snout is red-orange and the tail has horizontal, white and black striping. Other color variants, such as albino and golden types, are also available. The three main species that are commonly sold as rummy-nose tetras include:

• Hemigrammus rhodostomus (true rummy-nose tetra): standard red nose and striped tail
• Hemigrammus bleheri (firehead or brilliant rummy-nose tetra): more redness on the head that goes past the gill plate and sometimes has a tapered, diamond shape
• Petitella georgiae (false rummy-nose tetra): the middle black stripe on the tail extends onto the back half of the body and looks like a short, horizontal line

Besides their striking appearance, they are known for three interesting characteristics. First off, they tightly school together and change directions like a giant flock of birds. This behavior is useful for confusing predators, who will have a tougher time pinning down an individual tetra that is surrounded by a swarm of doppelgangers. Secondly, they can live in higher-than-normal temperatures in the low to mid 80s°F and therefore are often paired with other warmer water fish like discus, German blue rams, and Sterbai corydoras. Finally, they often get called the “canary in the coal mine” of aquariums because their noses lose their color when stressed. This visible indicator can help warn you of bad water quality, low temperatures, disease, bullying, or other problems in the aquarium. This happiness gauge is great for both beginners and veterans because you can instantly tell at a glance when things are going well or not.

How to Set Up an Aquarium for Rummy-Nose Tetras

The care requirements for these three species are very similar because they all come from blackwater rivers and streams in the Amazon basin. The water in these areas is very soft and acidic from fallen leaves, rotting wood, and other organics. However, we have found that they can do well in pH levels of 5.5–7.5 with soft to moderately hard GH. Despite their small size, a 20-gallon tank or bigger is more suitable because rummy nose tetras are active schooling fish that prefer a longer tank to swim back and forth. Plus, they enjoy warmer waters between 74–84°F (23–29°C), so get an aquarium heater if needed.

If you want to make a biotope setup that imitates their natural environment, cover the ground with catappa leaves, driftwood, and botanicals like alder cones. These organic materials will break down over time, tinting the water brown and gradually lowering the pH. Personally though, we find that their red and silver colors look amazing in a planted aquarium with lots of greenery. A darker background and substrate seem to make the tetras stand out even more.

How many rummy nose tetras should be kept together? While six is the typical number suggested for a school of fish, rummy-nose tetras need a bigger group to see their special swimming behavior. Get at least 8–12 tetras and you won’t regret it.

What fish can live with rummy nose tetras? They get along with any peaceful community fish that are similar-sized, such as other tetras, rasboras, and corydoras. Their bold personality makes them great dither fish for shy or territorial fish like Apistogramma dwarf cichlids. And as mentioned before, you can keep them at higher temperatures with other warmer water species. Conversely, do not put them with cooler water fish because of the mismatched temperature requirements. Like most fish, they will opportunistically snack on baby shrimp and fry, but they tend to leave the adult dwarf shrimp and snails alone.