Blog

Tetras in general, and Goldfish are both very popular and renowned fish species in the Aquarium trade. They have striking and bold colors, elegant features, and peaceful friendly personalities that most aquarists and pet owners seem to love.

The question has arisen as to whether you can keep Tetras or Goldfish species together in a communal aquarium, and according to a broad spectrum of scientific resources, the result of Keeping Goldfish and Tetras together has almost always had detrimental results.

It is vital to understand the needs and species specific of both Goldfish and Tetras individually, to comprehend why it is not recommended for them to live together.

Tetras As A Species

The Tetra (Tetragonopterus) is a specific genus referring to fish with square fins, or four-sided wings. Tetra is a more common name for small Characiform freshwater fish, consisting of many different species, originating from Africa, Central and South America, and belonging to the Characidae family, that is distinguished by its small adipose fin situated between the dorsal and caudal fins.

The tetra is an extremely popular fish family in the aquarium trade that many times contributes to unrelated fish including those from other families. The Neon Tetra (Paracheirodon innesi), one of the smaller Tetra species, is the most popular smaller-sized fish species for its vibrant neon blue and red stripes.

Depending on the exact species most Tetras have a lifespan of between 3 and 5 years, and over different resource platforms, there are said to be over 100 other Tetra species, with around 30 that are common in the Aquarium trade.

Tetras come in many sizes, shapes, and color variations, too many to go into detail. However, the common sizes are around 0.8 Inches (2 cm), which is the smallest, and smaller species are around 1 Inch (2.5cm), 1.3 Inches (3.30 cm), 1.5 Inches (3.80 cm), 1.75 Inches (4.5 cm). Slightly larger species of about 2 Inches (5 cm), and 3 Inches (7.6 cm) can be found. The size of Tetras as will be seen further on plays a role in whether they can coexist with Goldfish.

Goldfish Species Information

Goldfish, or (Carassius auratus) as they are scientifically known are freshwater fish from the Cyprinidae family, that is a very common fish kept in both aquariums and ponds, well known all over the world. Goldfish were initially a species of gray and silver Carp found in Asia that developed a tendency to produce either orange, red, or yellow color mutations, further selectively bred into many different species and colors of Common and Ornamental, or Fancy Goldfish species in the pet trade.

Similarly, the sizes of Goldfish may differ according to the specific species, and it plays a role in correlation to their cohabitation with Tetras. Goldfish typically range in size from around 4.7 inches (12 cm) and 8.7 inches (22 cm), though larger sizes of  16 inches (41 cm). Depending on the species Goldfish have a relative lifespan of between 5 and 15 years.

Two Common Goldfish families exist known as the Common Goldfish, consisting of the Wild Type Common Goldfish, Comets, and Shubunkin Goldfish, whereas Ornamental or Fancy Goldfish categorized as Veiltails, Fantails, or Moors, come in a much wider spectrum of variations and species.

Tetra And Goldfish Requirements Compared

Before addressing the Topic of whether Goldfish and Tetras can live together, it is vital to understand the separate needs of each species in basic terms, which will explain the conclusive answer. Keep in mind with so many different Tetra and Goldfish species, only basic care requirements were considered as each species may show slightly different needs or behavioral traits.

Tetras

Tetras are shoaling fish that prefer to be kept in groups. Their natural habitat comprises rivers and streams, with a more tropical climate, and they prefer more acidic soft water conditions. On the other hand, the neon Tetra prefers more densely planted environments and slightly more alkaline water conditions in comparison to most Tetra species. Caring for Tetras is relatively easy with the right tank setup and feeding regime.

• Aquarium – The tank size will mostly depend on the size of the Tetra species, You also need to consider that they must be kept in groups of six or more of their species. A tank of between 10 and 20 Gallons for smaller tetras and 20 – 30 gallons for larger Tetra species is required. In general, most Tetras require water temperatures of around 20 and 28 °C (68–82 °F) and a pH of between 5.0 and 6.0, with some species such as the Neon Tetras that prefer temperature ranges of 72–76 °F (22–24 °C), and a pH between 6.0 and 7.0. A fine gravel or sandy substrate is ideal, with ornaments such as terracotta pots, caves, rocks, and natural driftwood for a more natural feel. Synthetic or Live plants can be used, Neon Tetras prefer more dense vegetation, whereas other species enjoy open spaces for swimming.
• Feeding – Teras as a species are Omnivores and rely on a diet with some variety. They can be fed quality flakes or fine pellets, and a mix of balanced vegetables, along with protein-rich Brine Shrimp, Blood Worms, Daphnia, and Aquatic Larvae. They enjoy two meals a day, one being a main meal and the other a snack of meat-based and vegetable-based foods.
• Temperament and Behaviour – Most tetras are peaceful shoaling fish that prefer to be kept in larger groups as a natural instinct to ward off predators. If kept alone they quickly become stressed and slightly aggressive. Tetras usually get along with most other fish species, however, they have been known to nip at the fins of slow-moving fish with long-flowing fins. Tetras are fairly active and love to swim in hypnotic patterns through caves, plants, and gaps in their aquarium. An important fact is that tetras are excellent jumpers, thus a lid on your aquarium is a necessity.
• Breeding – Tetras are fairly easy to breed, though they do not provide any parental care whatsoever. They are egg scatterers laying between 300 and 600 eggs at a time. If you plan on breeding Tetras it is vital to have a separate breeding tank to keep the eggs and young fry safe.

Goldfish

Goldfish are hardy fish that can grow quite large, and easily survive in cooler water conditions in unheated aquariums and ponds, though it is not always optimal, especially not for Ornamental Goldfish. Goldfish are extremely easy to care for and one of the more sociable and intelligent fish species in the aquarium trade.

• Aquarium – Goldfish are known for producing plenty of waste, and thus need an aquarium with a strong filter and moderate current. For one or two Common Goldfish species a tank of at least 20 – 30 gallons is required. Goldfish are well known for adapting to the size of their living quarters, and will only grow to a mature size if given enough space. Generally, water temperatures of between 65 to 75 °F (18 to 24 °C) are preferred and pH levels of around 6.5 to 8.0. Goldfish can survive in ponds and unheated aquariums given that water temperatures do not fall too low below the required parameters. You can use a fine or medium gravel substrate in your Goldfish tank, and they enjoy toys and ornaments such as rocks, caves, PVC pipes, shipwrecks, and caves. Goldfish are highly intelligent with a well-developed sense of sight and hearing, thus they will need stimulation to keep them entertained. Live or synthetic plants can be used, though it is advised to use more robust Live plants as Goldfish can be slightly destructive.
• Feeding – Goldfish are natural omnivores enjoying plant material, along with small crustaceans and insects. Feeding them a balanced diet of fish flakes or pellets, blanched vegetables, and meat-based foods including blood worms, brine shrimp, and insect larvae is ideal. However, an important factor is that they require food low in protein, starch, and sugar consequently, as they are prone to digestive issues as they age.
• Temperament and Personality – Goldfish are known to be intelligent, social, and friendly creatures that can become quite tame, taking an interest in their human companions. On the other hand, they can be territorial during the spawning season.
• Breeding – With ample space and proper nutrition Goldfish can grow mature and will easily breed in captivity, given that the right water conditions are achieved. Though, like the Tetra they do not offer much parental care and may even eat their young fry.

Common Health Concerns In Goldfish And Tetras

In terms of health concerns, Common Goldfish are more robust than Ornamental Goldfish and less likely to become ill. Unfortunately, Tetras, on the other hand, are more likely to contract a disease, and much more fragile in this regard. A few main Health concerns in both Tetras and Goldfish include;

• Ich – A protozoan parasite that is mainly caused by introducing new tank mates or plants, and poor water conditions. It causes small white spots on the fins and body of a fish. Ich can be treated with proper quarantine for a week and medication.
• Swim Bladder Infections – The swim bladder, which is an organ that keeps fish afloat can become infected due to bacteria or a fungus, usually because of poor nutrition and water conditions. Depending on the infection it can be treated with antibiotics. The symptoms include lethargy, inability to stay upright or swim, and a loss of appetite.
• Fin or Tail Rot – Fin or tail rot causes a ragged and discolored appearance in the fins and sometimes the body of a fish. It is mainly caused by Ammonia burns or physical damage that has resulted in an infection. The condition can similarly be treated by antifungal or antibiotic medication, and quarantine is needed.
• Digestive Issues – Goldfish are more prone to irritable bowels and digestive issues, especially as they age. Feeding them a diet lower in protein, carbohydrates, and sugars will help. Goldfish also tend to overeat, thus they should be fed just enough to finish in a few minutes, twice a day.

Housing Tetras And Goldfish Together

It is only natural that individuals choose to house different fish species together, and given the sociable and friendly nature of both Tetras and Goldfish, along with their striking colors, the temptation to house them together may be irresistible.

Can Tetras Live With Goldfish?

In contrast with the basic care information given regarding tetras and Goldfish, it is clear why they cannot be housed together. So, unfortunately, NO tetras and Goldfish can live together in the same aquarium.

To recap here are the main reasons why you cannot keep tetras of any species or Goldfish together.

Reasons why tetras and goldfish are not compatible tank mates

• Tetras prefer higher water temperatures than what Goldfish can tolerate.
• Though tetras and Goldfish have the same diet, Goldfish tend to be prone to digestive disorders that can be affected by eating food meant for Tetras.
• On the other hand, because of their size, Goldfish may be prone to eat smaller tetra species such as the Neon Tetra.
• Goldfish generally require much larger tank space than Tetras, especially smaller Tetra species. In turn, the Goldfish will grow to their full size, which is much larger than that of Tetras.
• Goldfish produce plenty of waste, and thus regular water changes and cleaning are required, which is detrimental for tetras as they require a more constant living environment with few water changes.
• Teras is well known for being more prone to disease, and placing them with Goldfish will increase the risk of the Goldfish contracting the disease.
• Tetras prefer to travel in schools of their species and avoid other larger fish species. They will quickly become stressed and feel unsafe in a tank environment with larger Goldfish.
• Thus, so far it should be evident that the Living requirements and behavioral instincts of tetras and Goldfish are vastly different from each other, and therefore they should not be housed together.

In Which Circumstances Can Goldfish Live with Tetras?

Though not advised, the only circumstance where you can keep tetras and Goldfish together is when the Goldfish are still small and young. They could essentially live with your tetras for a few months but will have to be removed once they grow larger.

Can Neon Tetras Live with Goldfish?

There are a few instances where individuals have thought it appropriate to keep Neon tetras with Goldfish. Unfortunately either one of the species will be left with suboptimal living conditions. Even though Neon Tetras can survive in slightly lower temperatures, it will still be too high for Goldfish, and not optimal for the tetras.

Larger Goldfish may similarly resort to eating smaller Neon Tetras, and in contrast, Neon Tetras can become stressed and fearful of larger Goldfish. This difference in water temperature means that these two fish cannot live in the same tank.  As with most Tetra species, Neon Tetras are even more sensitive to water changes, and dirty water, thus living with Goldfish will not be ideal.

So conclusively as studies and established with much research on the subject, tetras of any size, and even smaller and faster moving Neon Tetras CANNOT be kept together.

What Species Of Fish Can Live With Tetras And Goldfish

According to research most Common Goldfish species are ideally not even suited to be kept with ornamental species. Essentially Goldfish species are better kept within their own species, and category.

So with that settled, all is not lost, and there are some options for more ideal companions for your Tetras or Goldfish:

1. Compatible Tank Mates For Tetras

Most Tetras will easily get along with other peaceful bottom-dwelling fish or shoaling fish that are similar to the size of the specific Tetra species in question, in general here are a few good choices in companions for your Tetras, though keep in mind the best tank mates for Tetras, are more tetras of the same species.

• Dwarf Peaceful Gouramis
• Rasboras
• White Cloud Minnows
• Zebra Fish
• Danios
• Bottom Feeding Loaches and Corydoras

For much smaller Tetra species the following tank mates can be considered:

• Neon Tetras
• Guppies
• Kuhli Loaches
• Endler’s Livebearers
• Danios

2. Compatible Tank Mates For Goldfish

According to many studies, it is strictly recommended that Ornamental or Fancy Goldfish should never be kept with Common Goldfish, as they are much more delicate and prone to fin nipping from Common Goldfish species. Most bottom feeders, especially Plecos are similarly not a good choice, as they tend to feed on the slime coat and even eyes of slower moving Goldfish.

All in all the choices of companions for Goldfish are few, and it is well advised to stick to common Goldfish species as companions, or certain Ornamental Goldfish as companions for each other. Other than that here are a few acceptable options:

• Platys
• Giant Danios
• Hillstream Loaches
• Rosy Barbs
• Banded Corydoras
• Zebra Danios
• Larger Snail Species

To Conclude

To conclude the discussion, there have been many studies done and resources provided that do NOT recommend housing Goldfish and Tetras of any species together, unless and also highly unadvised, the Goldfish are young and small enough. Goldfish and Tetras have immensely different care requirements and are conflicting species that should never be housed together.

Frequently Asked Questions