Care Guide for Dwarf Neon Rainbowfish – Housing, Food, And Breeding


Care Guide for Dwarf Neon Rainbowfish – Housing, Food, and Breeding

The neon dwarf rainbowfish is a beautiful, almond-shaped fish with an iridescent blue sheen that flashes under the light. This robust species is very active and pairs well with many peaceful, semi-aggressive and calm tank mates. This beginner-friendly rainbowfish is easy to care for.

What are Neon Dwarf Rainbowfish and How Do They Work?

Melanotaenia praecox is a 3-inch (8 cm) rainbowfish found in streams and tributaries of the New Guinea rainforest. The males have a shiny blue body with red-orange fins, whereas the females have a silvery body with yellow fins. These fish are one of the smallest Melanotaenia varieties and can be bought for around $5-$7.

How to Set Up an Aquarium for Neon Rainbowfish

Since they are a fast-swimming fish, we recommend keeping them in a longer aquarium, such as a 20-gallon long or 29-gallon tank at the minimum. Dwarf neon rainbows are native to tropical areas and can be kept at 74-80degF (23-25degC). While they can handle a wide range of pH and GH, they prefer harder, alkaline water. We like to add crushed coral to buffer the pH.

Neon rainbows look amazing in planted aquariums, and taller plants can help block line of sight when the males are tussling with each other. Rainbowfish love to swim freely, so make sure that the foliage isn’t too dense.

How many praecox Rainbows should you keep together? Rainbowfish are schooling fish that need at least six of the same species. While males are more brightly colorful than females, make sure to keep at least 1-2 females for every male to minimize their squabbling. Males are more expressive and have a shiny stripe on the top of their heads when they display their best colors in front females.

Can dwarf rainbowfish be kept with another fish? Because of their deep-bodied and quick speed they can get along with many other similar-sized tank mates. Their temperaments range from calm to aggressive. We have kept them with angelfish, pearl gouramis, tetras, corydoras catfish, and smaller cichlids. While they will make a meal out of your cherry shrimp, they seem to leave larger amano shrimp and filter shrimp alone.

What are Praecox Rainbowfish’s Favorite Foods?

These fish are easy to care for and will eat anything that is put in their tank. We give them small, slow-sink foods like frozen cyclops, brine shrimps, and nano pellets. They love bloodworms, flakes and fish food. It is important to offer a wide variety of food to ensure that they get all the nutrients they need.

How to Breed Dwarf Neon Rainbowfish

Rainbowfish are egg scatterers and do not require any parental care. As long as you have fish of both sexes and feed them well, they can easily spawn every day, but their 1 mm eggs produce very tiny fry that can be hard to raise. A floating spawning mop is placed in the tank. This allows the adults to lay eggs in the yarn strands. After a few days, fill a catch cup with water from the breeding tank and hang it on the inside of the tank in order to keep the water warm. Place the spawning mop full of eggs inside the catch cup and add an air stone to keep the water well-oxygenated. To prevent fungal growth, some breeders add a couple of drops of methylene blue or even a few cherry shrimp to help clean the eggs.

The eggs should be ready to hatch within a week. Fry must be fed with very small amounts of food, such as vinegar eels and microworms. Frequent water changes are also necessary to keep the water quality high. Two weeks after hatching, rainbowfish fry will be large enough for them to consume live baby brine shrimp. This is the best food available to promote healthy and quick growth.


The neon dwarf rainbow is a favorite because of its energetic behavior, iridescent scales and small size. Check out our list to find the best online vendors if your local fish market doesn’t stock them. However, if you’re looking for an even more petite species, read our care guide on the forktail blue-eye rainbowfish.