Neon Tetra Care: Tank Size, Tank Mates, and Water Conditions

Neon tetra fish are freshwater schooling fish in the family Characidae. As one of the most popular aquarium fish in the world, 2 million of them are imported into the USA each year. 

As peaceful community fish and active swimmers, they are excellent choices for beginners and experts alike. Neon tetras are one of the hardiest tetra species. Care is simple but breeding them takes more effort. The average neon tetra lifespan is 5 to 10 years.

• Common Names: Neon Tetra; Glow Neon Tetra; Neon Fish
• Scientific Name: Paracheirodon innesi
• Origin: Amazon River basin (North & West region)
• Length: 1 to 1½ inches
• Aquarium Size: 10+ gallons
• Temperament: Peaceful; Schooling
• Ease of Care: Easy

Neon Tetra Species Summary

Neon tetras were first described in 1936 and named after William T. Innesi, author and avid aquarist. They were an instant favorite and one of the many new tropical fish imported from South America. 

Wild neon tetra fish come from the rainforests of Brazil, Colombia, Peru, and Ecuador. Blackwater and clearwater streams in the Amazon rainforest are their preferred habitat. The majority of tetras in the pet trade are captive-bred in Southeast Asian fish farms.

Neon Tetra Appearance

Neon tetras are distinctive, with contrasting red and blue stripes along their flanks. The back is dark gray while the belly is silver. Neon tetras get their name from their bright blue stripe. It is iridescent and reflects even faint light like a safety vest. 

These stripes help a neon tetra school coordinate its movements in dark water. Predators that try to single out a fish also become confused by the flashing lights of the school. Many tetra species have a similar neon stripe, including glowlight tetras and black neon tetras. 

Reflective guanine crystals catch the light even when levels are low. When you turn the aquarium lights on, you’ll notice that your neon tetra’s stripes have a purple hue that’s more effective in the dark. The color then shifts to light blue to better reflect illumination during the day.

Neon Tetra vs Cardinal Tetra

The type of tetra that is most often confused with true neon tetras is the cardinal tetra (Paracheirodon axelrodi). Both species have blue and red stripes and are close relatives

Cardinal tetras are named for the red hats of Roman Catholic cardinals. That feature is the first clue: the red stripe of a cardinal tetra runs all the way to its gills. On a neon tetra the red stripe stops halfway along the body. 

Cardinal tetras have a chocolate brown back while neon tetras have a steel gray back. Neon tetras are smaller than cardinal tetras, which reach up to 2½ inches. 

Cardinal tetras are wild caught and are more expensive than captive bred neons. Since they come to the trade as imports, cardinal tetras are more sensitive to poor water conditions.

Neon Tetra Male vs Female

Neon tetras do display some sexual dimorphism. Males are smaller and slimmer than females of the same age. Females have a thicker stomach even when they don’t have eggs. The silver of their bellies ends up being more pronounced and the blue stripe has a slight bend in a female neon tetra. 

Neon Tetra Tank Size

A neon tetra tank does not need to be large. 10 gallons of space is enough for a school of 10 tetra fish. Fewer fish is acceptable so long as you keep at least 6 neon tetras together. Any fewer and they will hide from stress.

5-6 gallon aquariums are too small for neon tetras as these fish are active swimmers. The more water volume you provide them, the better. A 20 gallon tank is even better and ensures you have enough room for a diverse community of tank mates.

Water Conditions

Tetra fish prefer acidic to neutral water chemistry (pH 5.5-7.0). Neon tetras are found in blackwater streams as well where decaying plant material lowers the pH to 4.0-5.0. High acidity brightens their colors, increases their hardiness, and makes breeding possible. Water hardness should be at or below 10 dGH and 1-2 dKH for spawning.

Neon tetras kept in alkaline conditions (pH 7.0+) will live for years but show reduced appetite. They become more susceptible to aquarium fish ich and neon tetra disease.

The water temperature should stay elevated and stable at 75-80℉. Sudden temperature shifts are stressful or fatal. When performing a water change use a thermometer. Bring the water as close as possible to the aquarium’s current temperature before adding it to your tank.

Neon tetras are less sensitive to nitrogenous waste (ammonia, nitrite, and nitrate) than other tetras. Levels should still be kept low as they are not as hardy as livebearers and other beginner aquarium fish. 

Never add neon tetras to the tank first when cycling a new aquarium. Sudden rises in ammonia are dangerous to them. Tetras should be the last fish added to a new setup.

Neon Tetra Disease

Neon tetra disease is a fast progressing and fatal illness caused by a microsporidian parasite (Pleistophora hyphessobryconis). It was first identified in neon tetras and is also seen in other fish species. The source is spores that spread through contaminated fresh food or via the bodies of infected dead fish that a tetra nibbles on.

 Neon tetras are more prone to catching the disease when kept in alkaline water conditions and in the presence of elevated nitrogenous waste. These chemistry parameters lower disease resistance in tetras.

The disease manifests as pale cysts that develop under the skin. Scales start to become discolored and colors fade as the disease takes its toll. The affected fish spends less time swimming, eats less, and soon dies. 

The best medicine is preventing exposure to Pleistophora spores and clean aquarium conditions.

Aquascaping and Decorations

Neon tetra fish do best in well planted aquariums with driftwood and low light conditions. Plants give tetras a sense of safety. They will dart in and around them, displaying to each other. Tetras are egg scatterers that need plants for spawning as well.

Plants provide several water quality benefits; they consume nitrogenous waste as fertilizer. Plants provide extra dissolved oxygen and absorb carbon dioxide. The shade they provide keeps algae growth to a minimum. 

A mixture of stem, rosette, and floating plants works best for a neon tetra tank. Thick bunches of hornwort, moneywort, water wisteria, or eelgrass grow fast and need minimal care. Mix in Amazon sword plants, Cryptocoryne, and Java fern. 

For the surface, floating plants like red root floater and duckweed enhance your Amazonian swamp neon tetra habitat. Last, you’ll need driftwood pieces. Driftwood slow-releases tannins into the water, lowering the pH further.

What Do Neon Tetras Eat?

Neon tetras are carnivorous micro predators that eat small invertebrates in their natural habitat. Water fleas, worms, baby shrimp, and mosquito larvae are their usual prey. Captive bred neon tetras eat flakes and micro pellets and should be fed frozen or live food a few times per week. 

Brine shrimp, bloodworms, and tubifex worms are all easy to find at local pet stores. They offer extra fat and micronutrients that dried blends lack. Worms too large for a neon tetra to swallow need to be cut into smaller pieces first.

A neon tetra’s stomach is about the same size as its eye. Aim to feed that much food to your fish to avoid overfeeding. Feed these active animals 2 to 3 times per day.

Neon Tetra Tank Mates

Tank mates for neon tetras should be small and peaceful. Large fish that are peaceful are often predatory. Full grown angelfish aren’t aggressive yet they will still eat a neon tetra. Fish with small mouths that are big will intimidate smaller fish, causing stress. 

Neon tetra tank mates should be 1 to 4 inches in length, no larger. These fish should prefer soft, acidic conditions. Guppies and platies prefer hard water but are flexible enough to thrive in acidic conditions. More good neon tetra tank mates include:

• Betta Fish
• Other Tetras
• Guppies
• Platy Fish
• Zebra Danios
• Cherry Barbs
• Dwarf Gouramis
• Harlequin Rasboras
• Cory Catfish
• Kuhli Loaches
• Taiwan Bee Shrimp
• Aquarium Snails

Neon tetras are also safe with invertebrates. They won’t try to eat baby freshwater shrimp and don’t pick at the soft parts of snails.

Breeding Neon Tetra Fish

Spawning neon tetras is the one aspect of their care that is difficult. These fish have demanding chemistry needs for breeding. You have to provide an acidic pH that is low in dissolved minerals. Live plants are essential as a place for egg scattering. Provide live or frozen foods as well to ensure female tetras have enough fat for egg production.

Sexual characteristics are subtle in neon tetras so the best way to ensure a successful spawn is to keep as many of them together as possible. Keep 10 or more neon tetras in a mature, planted aquarium. Perform frequent water changes and keep light levels low using heavy floating plant cover.

Males will start to challenge one another and chase pregnant neon tetra females around. A gravid female will dart among plants with her chosen male during the early morning hours. They embrace and release fertilized eggs in bursts. Neon tetra eggs are pale yellow, sticky, and attach to the first thing they touch. 

Once your neon tetras spawn remove any plant stalks with eggs attached to a fry rearing aquarium. If you leave them the other fish in the aquarium will eat them, including the parent neon tetras. Tetra fish provide no parental care for their eggs or fry.

Neon tetra fry hatch in 24-48 hours. They are too small for crushed flakes or baby brine shrimp. Feed them live cultured infusoria for the first two weeks. Then switch to live brine shrimp nauplii and powdered flake food.