How big do rainbow fish get

How big do rainbow fish get?

How big do rainbow fish get?

The habitat of the fish is the mouth of rivers in Australia.

How big do rainbow fish get? They can get very large, 25 cm long depending on the species, there are also “dwarf” rainbow fish who are on average 3-5 cm long. This fish has a broad, flattened body of silver-blue color, rather a shade that cuts four longitudinal stripes. The dorsal and ventral fins are red, forked, like much other marine fish.

The fish is fast-moving, not aggressive, and does not touch any other fish of its kind. It eats any live and vegetable food.

The aquarium should be large enough, and there should be an open space in the middle, so this type of fish needs plenty of space to swim. Water should be well filtered and ventilated. Regular water exchange is required (once a week, 15-20% of the aquarium volume).
Water temperature: 22-28 ° C. water parameters: PH 6.0-7.5, DH: up to 10-12 °

Melanotaenia trifasciata is perhaps one of the most fertile species in the family Melanotaeniidae. It spawns very often and usually in a common aquarium. The incentive to spawn is the rays of the morning sun. The female lays eggs on Java moss. Immediately after spawning, the clutch should be moved to another aquarium, as parents often do not mind eating their eggs. Fry appears in about a week and the first food for you is small plankton and other crustaceans.

Boesemani Rainbowfish - Amazing Freshwater Aquarium Fish


For manufacturers of three-lane rainbows take an aquarium with a capacity of 60 liters depending on how big your rainbow fish get. The substrate is small-leaved plants in an aquarium with weight or in pots. On the leaves of these plants, the female hangs eggs, where they mature later. You can attach a washcloth made of nylon threads, knocked into a bundle, to the glass in the middle layers of water. The water in the spawning area is softer than in the aquarium where fish were kept before spawning.

The parent nest consists of one male and two or four females. During spawning, the male chases the female squeezes and knocks out her eggs. Every day the female lays 10-100 eggs.

Washcloth with caviar is taken and placed in an incubator. The maturation process of the embryo lasts 12 days. Fry are fed” living dust ” and tetramine, growing broods-live food, and compound feed. Feeding with dry and vegetable food is mandatory. They reach sexual maturity by six months.

Aquarium for rainbow fish

The purpose of this version of the aquarium is the same as the previous one – to achieve the coexistence of different fish species.

Soil – small pebbles. Lay there (at the edge of the sidewalls of the tank) Vallisneria. Leave the front part of the soil without soil and protect the pebbles with a stone barrier. Place the ambulance at the edge of the opposite side window. In the middle, on the back wall, you can place Elodea or ludwigia.

The composition of the fish in this aquarium features a black molly, Xiphophorus, Guppies, Poecilia, the dwarf gourami.

The water parameters are the same as in the previous aquarium.

For the successful development of plants, it is necessary to provide the aquarium with a good lighting device consisting of two types of lamps – luminescent (40 W) and incandescent (25-40 W). Replace the water in the aquarium is not more than a third of the water (lower layers) and not more than twice a month.


The main diseases affecting the rainbow fish relate to the diet and quality of food. If you mainly feed with mosquito larvae and bloodworms, it is possible to introduce parasites or infections into the intestines. Skin parasites are also introduced with live feed or with new neighbors who have not passed quarantine. If live food is excluded, the fish does not have enough immunity to fungal diseases. Prevention of diseases can be called the maintenance of the necessary water parameters, regular cleaning, aeration, and filtration of water.

Living in nature

Rainbow fish Melanotenia was first described by Weber in 1922 but appeared in aquariums in the 90s. They live in small rivers and streams in western New Guinea and in the Mamberamo region of West Papua. The water in these rivers is clear, with a rapid current, a temperature of 24-27C, and a pH of about 6.5. they feed on plants, food, insects, fry, and caviar. Fortunately, these areas are still among the worst explored on the planet, and the rainbow fish population is not yet threatened.


How big do rainbow fish get? It reaches a length of 5-6 cm, rarely more, for which it is also called a dwarf. The life expectancy is about 4 years but can vary between 3-5 depending on the aquarium conditions. Its body is elongated, laterally compressed, with wide anal and dorsal fins, and the dorsal fin is forked. The rainbow fish has bright fins, red in males, and yellowish in females. The color of the body is pinkish-gray, but the scales are blue and create a neon effect in different light angles depending on the species it can be anything.

Complexity in rainbow fish care in general

It will not be difficult for an experienced fishkeeper to contain a big rainbow fish. However, they cannot be recommended for beginners as rainbows are very sensitive to fluctuations in the aquarium and changing water parameters like the nitrogen cycle. In addition, despite their small size, they need a spacious aquarium. This is because it is better to keep them in packs of 10 pieces or more and the rainbow fish itself can get big.


Rainbow fish in nature eating both plant and animal food. In the aquarium, they like to eat high-quality artificial food, but it is important not to over-feed and use food that is slowly sinking. Rainbow fish collects almost no food from the bottom, so quickly sinking food is not suitable.

In addition, you need to feed live or frozen food: mosquito larvae, bloodworms, Artemia. You also like vegetable food, you can give precooked lettuce leaves, zucchini pieces, cucumbers, or feed with spirulina.

Rainbow fish care

Although these rainbow fish are called dwarfs because they are not so big, they are very active and live in a flock, so it is better to keep them in a spacious aquarium with a volume of 100 liters or more. Also, the aquarium must be tightly covered, as they are excellent jumpers and can die.

They like clean, fresh water with parameters: temperature 24-26C, ph: 6.5-8.0, 5-15 dGH.

All You Need to Set Up Your First Rainbow Fish Aquarium

It is advisable to use a powerful filter and generate a current in which neon rainbows like to frolic around. They look best in an aquarium that resembles their natural habitat. Sandy substrate, abundant plants, and driftwood as in their native rivers in Borneo.

Most rainbow fish feel good among a variety of plants. But at the same time, you need a lot of space for free swimming. It is most advantageous to have an aquarium with a dark bottom, and the sun rays would fall on it. It is in these hours that rainbow fish colors will look the most beautiful and brightest.


They are well suited to keep small and peaceful fish in a common aquarium. This is a school fish and the ratio of males to females is very important for breeding. If you think only of beauty, then men are preferable as they are more brightly colored. Depending on the size of the pack is the best ratio:

  1. 5 neon rainbows-of the same sex
  2. 6 neon rainbows – 3 males + 3 females
  3. 7 neon rainbows — 3 males+ 4 females
  4. 8 neon female rainbows — 3 males + 5 females
  5. 9 neon rainbows — 4 males + 5 females,
  6. 10 neon rainbows-5 males + 5 females.

Make sure there are more females per male, otherwise they will be under constant stress. Dwarf rainbows eat almost everything, but they almost never take food from below. So you need to clean the soil more often than with ordinary fish or speckled catfish or thoracata that absorb the remains of food. As for other fish, it is better to keep them with small and fast: Sumatra Barbus, fire-Barbus, black Barbus, Black tetra, etc. gender differences male strip and fins are reddish, while the female yellow or orange fins are. The older the fish, the more noticeable the difference. Also females are silvery.


Rainbowfish is a strange guest in our aquaria, which came from the lakes and rivers of Australia, New Zealand, and new Guinea. It is interesting that the number of species discovered and described is growing, but at the same time, some of them are not even given to one person. Civilization destroys the habitat of the rainbow fish. In aquariums, these small fish become wonderful inhabitants: active, mobile, and quite unpretentious. Water parameters are actually quite easy to maintain.