Myth: Betta-in-a-vase products mimic the betta's natural environment and create a stable internal ecosystem
Reality: One of the most dangerous elements of the betta fad is the betta-in-a-vase craze. These vases are undersized, over-exposed, fail to maintain adequate temperature, and often do not provide space for air-breathing. It should be easy to see through the suggestion that they mimic the betta's natural environment; what natural environment could a tall, narrow container half-filled with marbles with a plant plopped on top possibly be emulating? Certainly not a rice paddy, that's for sure! What's more, the assertion that the plants roots will sufficiently manage ammonia and waste production in the small container is preposterous; even in aquariums filled with aquatic plants, filtration and gravel cleaning are required.
Myth: Bettas kept in vases survive by eating the plant's roots; feeding and cleaning is not needed since this is a self-sustaining environment.
Reality: Bettas are carnivores (insectivores) by nature; in the wild, they eat a variety of insects, and occasionally the eggs and fry of other aquatic species. While they might will intermittently nibble at plant matter if hungry enough, they can not obtain adequate nutrition from plants. Any betta actively consuming the roots of a plant is likely doing so as a last resort while attempting to stave off starvation. They absolutely must be fed an appropriate carnivore diet. Furthermore, as mentioned above, the vase is not a self-sustaining environment. True, a starved betta will not produce as much waste as a well fed one, but bettas absolutely need water changes - especially when kept in inadequately sized containers like a vase.
Myth: Bettas, even in small and unfiltered tanks, do not require frequent water changes as they thrive in unclean conditions.
Reality: Tying back to the myth regarding the ideal water conditions of bettas, it is a common misconception that the species is found in dirty, muddy puddles, which has convinced some novice aquarists that clean water is not demanded of the species and could even be harmful. In reality, the opposite could not be more true. The selection for decorative and show finnage types in bettas has created fish that are in fact highly sensitive to water quality; unless conditions are pristine (right down to hardness and pH, even!), you can expect crown tails, half moons, and other long finned bettas to suffer deterioration of the finnage. The poor circulation to the extremities of these lofty fins also makes them a prime target for bacterial infections, a problem only exacerbated by unclean water. Make no mistake: there is no such thing as a fish that thrives in waste-laden, filthy water!
Myth: Bettas do not require heating or filtration.
Reality: While this is technically a myth, there is no simple counterpoint for a number of reasons.It is true that bettas can survive without a heater or filter, but only under highly specific conditions. For example, in a room heated to at least 76 degrees, a betta does not need an actual heater, but under normal room temperature conditions, they absolutely do. The ideal range of the species is 76-82 degrees (with a survival range of around 72-86), which under most conditions demands a heater. In regards to filtration, opinions are split. The benefits of a cycled, filtered tank are numerous and well supported. Unfortunately, the combination of yielding from stagnant water and having large, cumbersome fins can make filtration stressful, so many keepers (including traditional thai breeders) do not filter or cycle. Both methods seem to work so long as clean water and consistent water parameters are maintained.
Myth: Bettas are not tropical fish.
Reality: Many pet stores will tell customers that cold cups are not problematic because bettas are not tropical fish. I'm sure the people of Thailand would be interested to learn that they are living in a temperate climate! Bettas, like many other tropical fish, have an ideal temperature range of 76-82 degrees. They survive perfectly well in temperatures upwards of 86 degrees, but they can not thrive in temperatures below 72. While they may be hardy enough to survive outside of their ideal range, cool temps typically result in lethargy, constipation, fin rot, and an increased susceptibility to disease.