Green neon tetras are a favorite fish for aquascapers because their glowing blue stripe is so eye-catching yet doesn’t take away from the beauty of the aquarium plants. As the little cousin of the more common neon tetra, you can easily fit a small school of green neon tetras in a planted nano aquarium or get a huge swarm to fill a larger tank for an amazing visual impact. Find out what makes this species so special and how to keep them happy and healthy in your home.

What are Green Neon Tetras?

Paracheirodon simulans has many common names — such as the false neon tetra, green neon tetra, and blue neon tetra. They are known for the iridescent blue-green line running down the side of their body that seems to change hues depending on their mood, the environment, and the viewing angle. At night when the lights are off, the stripe becomes darker but is still clearly visible as a glittery royal blue or indigo shade. This color change is useful for hiding in the blackwater river basins of Brazil, Colombia, and Venezuela where they are commonly found.

What is the difference between cardinal tetras, neon tetras, and green neon tetras? These similar-looking relatives all have a blue horizontal stripe with a red stripe underneath it. The cardinal tetra is the biggest, grows up to 2 inches (5 cm) long, and has a full red stripe that stretches from the eye to tail. In the middle is the 1.5-inch (3.8 cm) neon tetra with a half red stripe that starts in the middle of their body and reaches the tail. The smallest is the 1-inch (2.5 cm) green neon tetra that has an iridescent turquoise stripe with only the faintest amounts of red.

Left to right: cardinal tetra (Paracheirodon axelrodi), neon tetra (P. innesi), and green neon tetra (P. simulans)

How to Set Up an Aquarium for Green Neon Tetras

The natural habitat of this South American tetra is surrounded by shady trees and other vegetation with tons of leaf litter, fallen branches, and other rotting organics that release acids into the water. Therefore, they can live in highly acidic waters between pH of 3.0–6.5 with very soft to moderately soft GH. That being said, they are a fairly hardy species that we have successfully kept in pH levels of 7.0–8.0 in our home aquariums, so talk to your local fish store to see what water parameters they are being held in.

Green neon tetras enjoy typical tropical temperatures between 74–82°F (23–28°C), so get an aquarium heater to keep them warm and cozy. Since they are used to slower flow, use a gentle sponge filter, or put a pre-filter sponge on your hang-on-back or canister filter to prevent them from being sucked up. Nano fish can often be shyer from fear of would-be predators, so consider creating an environment with dimmer lighting and lots of plants (especially floating ones) that offer shaded areas and hiding spots. A darker background and substrate will also help to make their colors really pop. To recreate a blackwater biotope with brown-tinted waters, cover the substrate with catappa leaves and driftwood that will release tannins over time.

How many green neon tetras should be kept together? With most schooling fish, we recommend keeping a group of six or more fish of the same species. That being said, they will feel a lot more comfortable if you increase their numbers to at least 10 green neons in a 10-gallon aquarium or larger.

What fish can live with green neon tetras? This peaceful nano fish can be kept with other friendly community species that are not too big to eat them. Since they mainly swim in the midwater region of the tank, try mixing them with bottom dwellers such corydoras catfish or a mild-mannered centerpiece fish like a honey gourami. The warm, sunshine yellow of the gourami visually pairs well with the cool colors of the green neons. Given their diminutive size, these tetras are usually safe to keep with adult dwarf shrimp, but they may try to snack on any babies that cross their path.

Green neon tetra in a planted aquarium

What Do Green Neon Tetras Eat?

This little omnivore is fairly low on the food chain, so in the wild, they opportunistically go after tiny crustaceans, worms, insects, algae, and various types of plankton. To make sure they get a full range of healthy nutrients and vitamins, feed a variety of small foods that can fit in their mouths — such as crumbled flakes, nano pellets, freeze-dried tubifex worms, and Easy Fry and Small Fish Food. Besides dry, prepared fish foods, they would love it if you offered live baby brine shrimp, frozen cyclops, and daphnia.

How to Breed Green Neon Tetras

Egg-scattering fish tend to be harder to successfully breed in general, since there is such a high rate of predation on the eggs. An added difficulty with breeding cardinal, neon, and green neon tetras is that the eggs are sensitive to light and must be kept in darkness. If you are up for the challenge, set up a seasoned, 10-gallon blackwater aquarium with very low pH and GH. You may need to use RO (reverse osmosis) water with blackwater extract, catappa leaves, and other pH-lowering substances. To prevent the adults from eating their own eggs, create a grid-like barrier — using plastic craft mesh or egg crate wrapped with netting — that covers the entire footprint of the tank. Set the barrier on four PVC pipes that are about 3–4 inches (7.5–10 cm) tall so that the eggs can fall through to the bare bottom of the aquarium. Then place lots of java moss on top of the barrier as spawning sites, and weigh them down with small stones if needed.

The adults should be conditioned for breeding in a separate tank with heavy feedings of live foods. Isolate the males from the females if needed to increase egg production. Once the females are swollen with eggs, place at least one male and one female (or a whole group of conditioned adults) in the special spawning tank in the evening and do not feed them. By the next day, the adults should have released their eggs and you can remove them from the spawning tank. Keep the lights off for the first 5 days, and then the fry should be free-swimming and ready to be fed. Because they are so small, offer them miniscule foods — like green water, infusoria, and live vinegar eels — multiple times a day to keep their bellies full. Once they are large enough, switch over to live baby brine shrimp to help them grow strong and healthy.

School of green neon tetras with driftwood

Hopefully, you have fallen in love with the beautiful green neon tetra like we have. While we do not ship live fish, you can shop with our preferred online retailers and see the latest aquatic animals they have in stock. To learn about other types of popular tetras, read about the top 10 tetras that will look amazing in your next community tank.