Neon tetra care for beginners

Neon tetras are tiny, peaceful and one of the most popular aquarium fish in the world. They are easy to keep once your tank is settled, but they don't do well in a brand-new tank. Here's how to keep a school healthy.

Neon tetra facts

• Size: about 1.5 inches
• Tank: 10 gallons or more, and 20 is better for a proper school
• Temperature: 72–80°F
• Water: soft to medium, with a pH of about 6 to 7.5
• Group: 6 or more, and they look best in groups of 10 or more
• Lifespan: about 5 years with good care

Neon or cardinal tetra?

They look alike. On a neon tetra, the red stripe runs only along the back half of the body. On a cardinal tetra, the red runs the whole length. Cardinals grow a little bigger, like warmer water (75–82°F) and need at least 20 gallons. Neons are the hardier choice for a first school.

Only add neons to a settled tank

This is the most important rule. Neons are sensitive to the ammonia and nitrite spikes that happen in new tanks. Cycle the tank first, and ideally let it run with a few hardier fish for a month before adding neons. Test the water before you buy, and acclimate them slowly.

Setting up a neon tank

• Plants and shade. Neons come from dim, plant-filled streams and show their best color with cover. Easy live plants and some floating plants are ideal.
• A dark substrate makes the blue and red stand out. See the best gravel and sand.
• A gentle filter. They're small swimmers, so avoid strong currents. See the best aquarium filters.
• A heater to keep the water steady. Use the heater calculator for the right size.

Feeding neon tetras

Neons have tiny mouths. Feed small flakes or micro pellets once or twice a day, only what they eat in about two minutes, and add frozen or freeze-dried bloodworms or daphnia once or twice a week. See how often to feed fish.

Tankmates

• Good: other small peaceful fish such as harlequin rasboras, pygmy corydoras, honey gouramis, otocinclus, cherry shrimp and snails.
• Avoid: anything big enough to swallow them, including adult angelfish, and fin nippers such as tiger barbs. Bettas sometimes work, but they may chase neons.

Common neon tetra problems

• Faded color. Neons go pale at night and when stressed. Color that stays faded in the day usually means poor water, so test it. See ammonia in a fish tank.
• Deaths in the first weeks. Usually from a tank that isn't cycled or a big change in water. See why are my fish dying?
• Neon tetra disease. A parasite that makes a pale patch under the skin, a lumpy or curved spine and a fish that swims alone. There's no reliable cure, so move the fish out quickly to protect the rest. Quarantining new fish is the best protection.
• White spots are ich, which is treatable. See ich: white spots on fish.

Related: Best fish for beginners · 20 gallon stocking ideas · Corydoras care