Tetras are one of the most easily-available groups of fish in the hobby. There are many species of tetras, and some are perfect for newcomers to fishkeeping. Other species are much more challenging, and best avoided unless you’ve kept tetras before.
Before you buy any tetra, know this: tetras are schooling fish. This means they prefer to be kept in a group. Most species of tetras are happiest in groups of six or more of their own kind. Since you are buying multiple fish, it is even more important to check the size the tetras you want will grow to. Six six-inch bucktoothed tetras will need a lot more room than six 1.2-1.5 inch Neon Tetras.
It is also good to know that most tetras are happiest in somewhat acidic water, although water requirements vary greatly by species. Some are a lot more particular about water pH and cleanliness than others.
Good tetras for beginners:
-Black Skirt, Black Widow, White Skirt (they are all the same species)
-Head and Tail Light Tetra
-Serpae Tetra (but can be fin nippers)
-Red-Eye Tetra (but gets bigger than most and can be fin nippers)
This is a partial list, as there are many tetras that some people find easy and others difficult. One reason for these differencs in opinion is local water conditions. Someone in an area with soft, acidic water conditions is likely to find keeping and breeding Cardinal tetras easier than someone in an area with hard, alkaline water. Cardinal tetras really do need the acidic water, while Red-Eye tetras do not.
Other factors: Neon tetra disease
Another factor that makes a difference to whether you’ll have success with a species is disease. Some tetras are more prone to Neon Tetra disease than others. This disease is very difficult to cure, and is impossible to cure with standard propriety aquarium remedies. It is contagious, and can often lie dormant. It then awakens when something stresses the fish. Do not buy fish with visible Neon Tetra disease, or susceptible species from a tank where any fish shows Neon Tetra disease. If you do this, you are setting yourself up for frustration and heartbreak.
Neon tetras used to have a good reputation for hardiness, but now the vast majority of them are mass-bred in the far east with no attention paid to health or quality. This means that the Neon Tetras you buy now are often carrying this parasite when you buy them and die easily. If you can get disease-free Neons they are great fish, but Neons with this disease aren’t worth buying no matter how low the price. I wouldn’t knowingly take Neons with this disease if they were free.
Neon Tetras are notoriously susceptible, but danios, cichlids and most charachins can be susceptible to Neon Tetra disease as well.
The most common recognisable symptom of Neon Tetra disease, Pleistophora hyphessobryconis, is loss of coloration with pale or white patches of skin, most commonly below the dorsal fish. There are also other symptoms that include spinal curvature, emaciation, fin deterioration and erratic swimming. Do not buy any fish that shows these symptoms!
Just to make life more complicated, there is a False Neon Tetra disease that shows many of the same symptoms. This is a bacterial infection that can be cured by antibiotics.
Most tetras you buy will be healthy and hardy when treated right, as well as peaceful and beautiful. Overall, they are good beginner fish if you can avoid those sick with Neon Tetra disease, as well as a few species that have special requirements.
Tetra fish for beginners to avoid:
-Rummynose Tetras (disease prone, sensitive to water quality)
-Cardinal Tetra (needs acidic water, if you have that they are easy)
-Bucktoothed Tetra (grows to 6in and can be predatory)
-Fruit Tetras (these are White Skirt tetras that have been dyed. The process is bad for the fish and they are more likely to get sick than regular White Skirts. The color wears off with time, too.)