Loaches make up a group of largely bottom-dwelling fish from the families Balitoridae, Botiidae, Cobitidae, Gastromyzontidae, Nemacheilidae, Serpenticobitidae and Vaillantellidae. Few aquarium fish exhibit the level of personality that many loach species are known for and many aquarists frequently interact with their loach pets. Loaches are found throughout most of Asia, from tropical to temperate zones and range in size from under 2” to nearly a foot long.
Loaches occur in rivers, as well as a variety of slow and swift moving streams, depending on species. The bottom is frequently strewn with gravel, pebbles and smooth boulders, but sandy areas are also present. In most habitats plants are scarce to non-existent.
Loaches come from a variety of water conditions, but most will thrive in the average aquarium. The pH level should be maintained between 6.0 and 8.0, with alkalinity between 3° and 10° dKH (50 to 175 ppm). All loaches require clean, well oxygenated water with moderate to strong flow. Temperature requirements vary depending on species.
Loaches are gregarious, and if possible, should be purchased in groups of 6 or more. With so many species to choose from, no matter what size aquarium or type of fish you own there is one just right for you. Most loaches are quite peaceful and do well in community tanks, however, some members of the family Botiidae can become boisterous and may go after smaller or slower moving fish. These species are best kept with larger, more active fish.
While most loaches will accept a wide variety of foods, special consideration should be given to those species that come from fast moving water, such as the Hill Stream loaches. Many of these fish feed on algae, cyanobacteria and other micro-organisms that colonize rocks on the bottom. These fish should only be placed in mature aquariums with plenty of appropriate rockwork.