Betta Fish and Aquarium Glossary
Every specialist term this site uses, defined in plain English.
Aquarium writing is full of jargon, and most of it is never explained. Any term on this list is linked to its definition the first time it appears in an article, so you never have to leave the page guessing.
- Ammonia
The waste product fish excrete, also produced by uneaten food. Toxic at any detectable level, it burns gills and fins. In a cycled tank it should always read zero.
- Biofilm
A thin, slippery layer of bacteria and microorganisms that grows on aquarium surfaces. Usually harmless and often beneficial, though a heavy surface film can indicate poor gas exchange.
- Bubble nest
A raft of saliva-coated bubbles a male betta builds at the surface for eggs. It often indicates a comfortable fish, but its absence does not mean anything is wrong.
See also: flaring
- Cycling
The process of growing bacteria that convert ammonia to nitrite and then to nitrate. A tank is cycled when it can process a dose of ammonia to zero, with zero nitrite, within about 24 hours.
- Flaring
When a betta spreads its gill covers and fins to look larger, usually at a rival, its reflection, or something unfamiliar. Brief flaring is normal; constant flaring is a sign of stress.
- GH(general hardness)
The concentration of dissolved calcium and magnesium in your water. Bettas tolerate a wide range, but sudden changes stress them more than the absolute value does.
See also: kh
- KH(carbonate hardness)
The capacity of water to resist pH change, sometimes called buffering capacity. Low KH lets pH swing quickly, which is harder on fish than a stable pH at an imperfect value.
See also: gh
- Labyrinth organ
An air-breathing organ that lets bettas and gouramis take oxygen directly from the water surface. It solves oxygen, not water quality, so it does not make small or dirty water safe.
- New tank syndrome
Fish loss caused by stocking a tank before it has cycled, so ammonia and nitrite climb with no bacteria to process them. It is the most common cause of early betta deaths.
- Nitrate
The final stage of the nitrogen cycle and much less harmful than ammonia or nitrite. It accumulates over time, which is the main reason for routine water changes.
- Nitrite
The second stage of the nitrogen cycle, produced as bacteria break down ammonia. Still toxic to fish, and it should read zero in a cycled tank.
- ppm(parts per million)
The unit most aquarium test kits use, equivalent to milligrams per litre. A reading of 0.25 ppm ammonia means a quarter milligram of ammonia per litre of water.
See also: ammonia