Optimal Tank Conditions for Rummy Nose Tetras

Rummy nose tetra (lat. Hemigrammus rhodostomus) is a fish with bright red spot on its head, its fluke has black and white stripes and the body is silvery. At that tetra is quite small fish – about 4.5 cm long, with a peaceful temper and it can be a good tank mate for any peaceful fish.

Habitat in the wild

Rummy nose tetra (Hemigrammus rhodostomus) belongs to the family Characidae, which is a large family of freshwater fish commonly known as characins or characids. Characidae is one of the most diverse fish families and includes numerous popular aquarium species like tetras, hatchetfish, piranhas, and pencilfish, among others.

Rummy nose tetra habitat is in South America. The fish comes from the river Rio-Vaupes, Colombia and the Rio Negro river in Brazil. Also inhabits in the Amazon river tributaries. These rivers water has brownish tint and is highly acidic, since there are a lot of fallen leaves and other organics on their bottom.

In fact, there are 3 types of rummy nose tetra that can be encountered with such a name. The classical Hemigrammus rhodostomus actually is a rummy-nose tetra. Brilliant rummy-nose (Hemigrammus bleheri) was discovered later and it inhabits in other parts of Brazil. And one more fish – Petitella georgiae or false rummy-nose, which inhabits in water with higher hardness level.

Though the fishes have different requirements as for their care, they are very much alike and only true specialists can see between them.



Rummy nose tetra body is semi-transparent with greenish tint. When the fish is stressed, its red coloring gets pale significantly. The fish’s flesh fin and fluke are whitish, when the other fins are completely transparent. There are three wide black stripes on fluke, they go between four more thin white stripes. There are three black elongated spots on the fish’s tail-stem.

The most significant feature of rummy nose tetras is their bright-red spot on the head, due to which the fish got its name. Is your rummy nose tetra not red? It has a unique ability to change its bright red color into pale color, if the tank water is too contaminated or has a big amount of nitrates and ammonia in it.


Rummy nose tetras are relatively small fish. On average, they grow to be around 1.5 to 2 inches (3.8 to 5 centimeters) in length. Their small size makes them a popular choice for community aquariums, as they can comfortably coexist with a variety of other peaceful fish species.


When kept in a well-maintained aquarium with suitable water conditions and a balanced diet, rummy nose tetras can live for 3 to 5 years. As with any fish, providing them with proper care and a suitable environment is crucial for their overall health and well-being.

Scientific NameHemigrammus rhodostomus
Common NameRummy nose tetra
OriginSouth America (Amazon River basin and its tributaries)
Maximum SizeApproximately 2 inches (5 centimeters)
Lifespan3 to 5 years
TemperamentPeaceful, non-aggressive
Schooling BehaviorActive schooling fish, prefers groups of at least six
Water ParameterspH: 6.0 – 7.5, Temperature: 72°F – 82°F (22°C – 28°C)
Tank SizeMinimum 15 gallons for a small group
DietOmnivorous – Accepts both flake and live/frozen foods
ColorsSilver body with red coloration on the nose
CompatibilityGenerally peaceful and compatible with most community fish

Difficulties in keeping

Is rather demanding fish and it’s not for unexperienced aquarists. To keep this fish in a tank you should be very attentive to water purity and parameters, besides the rummy nose tetra is very sensitive to ammonia and nitrates content in the water.

Care and keeping in a tank

School size

The number of rummy nose tetras (Hemigrammus rhodostomus) you can keep in an aquarium depends on the tank size and the available space for the fish to swim comfortably. These tetras are schooling fish, which means they prefer to be kept in groups. Keeping them in groups allows them to feel more secure and reduces stress, resulting in more natural behavior and better overall health.

As a general guideline, you should aim to keep a group of at least six rummy nose tetras. This will provide them with a sense of security and allow them to display their natural schooling behavior. However, if you have a larger aquarium, you can certainly keep more than six. In larger tanks, you could have a school of 10 to 15 rummy nose tetras, or even more, depending on the tank size and compatibility with other fish species in the aquarium.

Remember that providing ample swimming space and hiding spots through the use of plants, rocks, and decorations is essential for creating a comfortable environment for your rummy nose tetras. Proper filtration and regular water changes are also crucial for maintaining good water quality and ensuring the health of your fish.

Tank size

As a general guideline, a minimum tank size of 30 gallons (approximately 114 liters) would be suitable for a small group of rummy nose tetras, such as six individuals. However, if you plan to keep a larger group or add other fish species to the tank, you will need a bigger aquarium to accommodate them all comfortably.

For larger groups of rummy nose tetras or if you want to have a more diverse community tank, consider getting a larger aquarium. A tank size of 30 to 50 gallons or more would be appropriate for a larger school of rummy nose tetras along with some compatible tank mates.

It’s essential to ensure that the tank provides ample swimming space and enough hiding spots through the use of live plants, driftwood, and decorations. Keeping the water quality pristine with proper filtration and regular water changes is also crucial for the health and well-being of your rummy nose tetras.

Water parameters

Rummy nose tetra is more demanding to the tank conditions than other fishes. Maintaining proper water parameters is crucial for the health and well-being of rummy nose tetras (Hemigrammus rhodostomus) and other aquarium inhabitants. The fishes show the best of their coloring and activity in the water with parameters close to the ones they have in the wild. This is soft and acidic water typical for rain forests – blackwater. That’s why it’s not sensible to put fish into a new not balanced tank, where water parameters are still changing.

Here are the recommended water parameters for rummy nose tetras:

  • Temperature: 72°F to 82°F (22°C to 28°C)
  • pH: 6.0 to 7.5
  • Hardness: 2 to 10 dGH (general hardness)
  • Ammonia and Nitrite: 0 ppm (parts per million)
  • Nitrate: Below 20 ppm (regular water changes can help control nitrate levels)

It’s desirable to use an external filter, since they are sensitive to ammonia and nitrates content in the water. That’s why the water should be regularly renewed: 30% of water capacity should be added once a week as well as the external filter should be used – this is how your fish will surely get its initial coloring back.


The tank lights should be dim, because in the wild rummy nose tetra lives in the areas with a lot of trees and leaves above the water surface. School will feel comfortable in well balanced, thickly planted tank.


Rummy nose tetras are omnivorous fish, which means they eat a combination of plant matter and small animal food. In the wild, they primarily feed on small insects, insect larvae, zooplankton, and plant matter.

In the aquarium, you can provide a varied diet to ensure their nutritional needs are met. Rummy nose tetra can eat all types of live, frozen and artificial feed. A balanced diet for rummy nose tetras may include the following:

  1. High-quality Flakes or Pellets: You can feed them specially formulated tropical fish flakes or pellets. Look for products that contain a variety of nutrients and are suitable for small tropical fish.
  2. Live or Frozen Foods: Offer them occasional treats of live or frozen foods like brine shrimp, daphnia, mosquito larvae, or bloodworms. These foods provide essential proteins and nutrients.

It’s essential to feed them in small portions that they can consume within a few minutes. Overfeeding can lead to poor water quality and health problems. Feed them 2-3 times a day, adjusting the amount based on their appetite and the number of fish in the tank.

By offering a diverse diet, you can ensure that your rummy nose tetras get all the necessary nutrients for their health, vibrant colors, and overall well-being.

Tank mates

Is a peaceful and schooling fish. Care should be very delicate, since the rummy nose tetra gets scared when transferring and transporting it (it may be shocked – it may freeze and stop moving or move harshly and uncoordinated, the body gets dark).

The rummy nose tetra may die because of this. Of course, rummy nose mustn’t be kept in one tank with large and predatory fishes. Tank mates can be:

Gender differences: male vs female

Distinguishing between male and female rummy nose tetras can be quite challenging, as they exhibit minimal sexual dimorphism. Sexual dimorphism refers to the physical differences between males and females of the same species.

In the case of rummy nose tetras, both males and females have similar body shapes and coloration. They are generally small, with a silver body and a striking red coloration on their nose and face. The red color is more intense and covers a larger portion of the nose in healthy and well-maintained individuals.

The most reliable way to determine the sex of rummy nose tetras is by observing their behavior during spawning. During the spawning process, females will become noticeably plumper as they fill with eggs. Additionally, males may show more intense red coloration on their nose and body to attract females and establish dominance.

However, unless you are a seasoned breeder or observe spawning behavior, it’s challenging to visually differentiate between male and female rummy nose tetras. In most community aquariums, knowing their sex may not be essential, as they are usually kept for their striking appearance and schooling behavior rather than for breeding purposes. If you are interested in breeding rummy nose tetras, creating specific breeding conditions and closely observing their behavior during spawning will be necessary to determine their sex more accurately.


Becomes reproductive depending on the tank conditions they live in, in the average it’s the age of 8-12 month. Optimal size of a spawning pond tank is 50×40×40 cm and the water level in it should be about 15 cm.

The main difficulty in breeding is to choose the rummy nose tetra males correctly. The fishes that are about to breed are usually put apart before spawning. During this time their diet should include different live feed. Water temperature should be risen at 1-2°, hardness is gradually decrease up to 4-6°, pH level 6.6-6.8.

For breeding rummy nose tetras you’ll definitely need a protective net. The water should be prepared by mixing the equal amount of rainwater, settled water and some turfy brew.

This water has to be thoroughly filtered and poured into the tank prepared several days earlier than the breeding fishes will be put in it. At this time water parameters are to be the following: hardness 2-4°, pH 6-6.2, temperature 25-27 °C. If the fish didn’t start spawning in 1-2 days, rise the temperature at 1-2° and than gradually decrease it at 2-3° with simultaneous adding of osonized settled water through a drop bottle. At first male actively haunts the female.

She goes to the water surface and it seems that she stops vertically under a tank plant leaf. At that the male comes close to her and bends and turns the female. When they part about 6-7 large transparent eggs fall on the tank plants and bottom.

The number of eggs depends on how strongly the male turns the female. This happens about several dozen times. After spawning the rummy nose tetras hide in the tank plants and their coloring gets pale. At this moment they should be removed from the spawning pond and the tank should be shaded with some dark paper.

Juveniles incubation time is 24 hrs and start to swim just in 6 days after they appear from eggs. Compared to other species of tetra fishes these juveniles are very large. Now you can remove the plants and net from the tank and feed the fishes. As a rule rummy nose tetra juveniles are not demanding to the feed: they eat cyclops dust, rotifers. Fishes grow very fast.

Just when being 1 month old the juveniles get the coloring of adult species: their head becomes red and black and white stripes are seen on their tail.

In 4 month their gender can be defined and in 6-8 month rummy nose is ready for breeding. Spawning period is the same as all tetra fishes have – 7-10 days. While the juveniles grow you can gradually make the tank water harder.