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Tetra Fish Care Sheet

Developed with and approved by a qualified veterinarian.

tetra care sheet

This care sheet covers a variety of tetra species, including: 



Scientific names: Paracheirodon innesi, Hyphenssobrycon callistus, Hyphessobrycon herbertaxelrodi, Paracheirodon acelrodi, Megalamphodus megalopeterus, Prionobama fillgera, Moenkhausia pittieri, Hyphessobrycon erythrostigma, Hemigrammus erythrozonus, Phenacogrammus interruptus, Petitella georgiae

Tetras are a very diverse group of small fish who belong to the order of Characiformes and are extremely popular in the aquarium hobby. Tetras are close relatives to pacus and piranhas. A community-based species, these schooling fish do best in odd-numbered groups of five or more.  Most of these colorful fish species have a calm, peaceful disposition.

Typical appearance and behavior

  • Very active. Most species will swim in the middle to lower levels of the aquarium
  • Tetras do best when kept in schools of five or more of the same species; odd numbers are recommended to prevent pairing and aggression
  • Tetras are omnivores, feeding on items from meat to plant-based foods
  • Tetras possess an adipose fin and homocercal caudal fin


Care Difficulty Beginner to intermediate, depending on the species
Average Life Span Up to 10 years, with proper care. Depends on species
Average Adult Size 1 1/2-5 inches long, depending on the species
Diet Omnivore
Minimum Habitat Size 10+ gallons, depending on the species
Water Temperature 72-82°F


Habitat size

Keep in an appropriate-size aquarium for the species selected, which can range from 10 gallons for smaller species to a much larger aquarium for a school of tetras.

Building your habitat

Water health -

  • Provide proper filtration to ensure optimal water quality to help maintain health. Slow to moderate water circulation should be provided to mimic water currents and high oxygen levels found in the tetra’s natural habitat. Stable water quality (pH, ammonia, nitrate, nitrite) and water temperature are critical to the health of aquatic life. If you are unsure of your water quality, bring a sample to Petco for free testing
  • An aquatic heater should be used to stabilize water temperature, ensuring it does not fluctuate more than 2 degrees in either direction in a 24-hour period
  • Many tetras will benefit from the addition of freshwater salt to the aquarium; the specific gravity should be kept at 1.004. Always research your species-specific needs before adding freshwater aquarium salt. Do not allow specific gravity to fluctuate more than 0.001 in either direction in a 24-hour period

Décor- Provide plenty of space for swimming and hiding places, as well as plants, rocks and décor for hiding

What do tetras eat?

A well-balanced tetra diet consists of:

  • Pellets, flakes, frozen or freeze-dried food
  • Treats, including bloodworms or brine shrimp (frozen or live)

Things to remember when feeding your tetras:

  • Feed small amounts one to two times a day. No more than fish will eat in 1 to 2 minutes.
  • Thaw frozen food before feeding

Tetra care

Maintaining great water quality with regular water changes and adequate filtration is important to help keep your tetras healthy

  • Daily: Check filter, water temperature and other equipment
  • Weekly: Test water quality at least once a week
  • Weekly to monthly: Change 10 to 25% of the total volume of water every two to four weeks or as needed; change filter media monthly

Avoid overcrowded conditions, which are a major cause of stress and disease

Where to buy tetras

Various tetras are available for purchase at Petco online and in store; availability varies by location. If visiting your local Petco Pet Care Center, please call ahead to check availability


Tank mates

  • Danios
  • Rasboras
  • Guppies
  • Mollies
  • Platies
  • Swordtails
  • Gourami
  • Cory catfish
  • Hatchets
  • Rainbowfish
  • Glofish


Signs of a healthy fish

  • Eats vigorously
  • Clear eyes
  • Swims actively
  • Regular breathing
  • Bright, even coloring
  • Free of parasites or disease

Red flags (If you notice any of these signs, contact your local aquatic specialist or aquatic veterinarian.)

  • Loss of color
  • Spots or fungus on body or mouth
  • Erratic swimming
  • Labored breathing
  • Elevated scales
  • Frayed fins
  • Weight loss
  • Bloating
  • Cloudy eyes or pop-eye
  • Loss of appetite

Common tetra health issues

Health Issue Symptoms or Causes Suggested Action
Health IssueFin rot Symptoms or CausesFrayed or disintegrating fins; the base of the fins usually reddens. Suggested ActionImprove water quality; consult your local aquatic specialist or aquatic veterinarian for treatment.
Health IssueIch Symptoms or CausesWhite spots appear on fins and body; fish rubs against hard objects or swims erratically. Suggested ActionTreat entire aquarium with a commercial parasite remedy and improve water quality; freshwater or saltwater (depending on specific gravity being kept at) dips can help dislodge the parasites; consult your local aquatic specialist or aquatic veterinarian for treatment.
Health IssueFungus Symptoms or CausesWhite, cottony growth and/or discoloration of the eyes. Suggested ActionQuarantine fish; use a commercial antifungal remedy as directed; consult your local aquatic specialist or aquatic veterinarian for treatment.
Health IssueBacterial infections Symptoms or CausesCloudy eyes, open sores and/or reddening of the skin. Suggested ActionImprove water quality; add freshwater aquarium salt; use a commercial antibacterial remedy as directed; consult your local aquatic specialist or aquatic veterinarian for treatment
Health IssueCottonmouth or columnaris Symptoms or CausesCottony white growths along the body and/or gills, frayed fins and gills turn brown and necrotic in late stages; caused by bacterial infection. Suggested ActionQuarantine fish; improve water quality; lower aquarium temperature to 72°F to deter bacteria from growing; medicate as directed; consult your local aquatic specialist or aquatic veterinarian for treatment.


  • How big do neon tetras get? Neon tetras can reach an adult size of 1.5 inches.
  • What type of fish are compatible with neon tetras? Species like rasbora, zebra danios, guppies, dwarf gouramis and platies are some of the fish who make good tank mates for neon tetras.
  • How big do tetra fish get? Tetras can reach an adult size of 1.5 to 5 inches depending on the species.
  • How many tetra fish can live together per gallon of aquarium? You should utilize the rule of 1 inch of adult fish per gallon of water when adding aquatic life to an aquarium.
  • What do you feed tetra fish? A well-balanced diet for tetras consists of a variety of flakes, pellets, freeze-dried and frozen diets.
  • Is a betta a tetra fish? Bettas are not a member of the tetra family but a member of Osphronemidae.
  • What are the different types of tetra fish? There are several different species of tetras, including neon tetras, serpae tetras, black neon tetras, cardinal tetras, black phantom tetras, bloodfin tetras, diamond tetras, bleeding heart tetras, glowlight tetras, Congo tetras and rummy nose tetras.

Additional care sheets

Notes and resources

Ask a Pet Care Center associate about Petco's selection of products available for the care and happiness of your new pet. All products carry a 100% money-back guarantee.

Because all aquatic life are potential carriers of infectious diseases, such as atypical mycobacterium and salmonella, always wash your hands before and after handling your aquatic life and/or habitat contents to help prevent the potential spread of diseases.

Pregnant women, children under the age of 5, senior citizens and people with weakened immune systems should contact their physician before purchasing and/or caring for aquatic life and should consider not having aquatic life as a pet.

Go to the Centers for Disease Control at for more information about aquatic life and disease.


The information on this Care Sheet is not a substitute for veterinary care. If you need additional information, please contact your veterinarian as appropriate.