Glossary
Plain-language definitions of the terms used across Gallons and Fins.
- Alkalinity (KH)
- The water's capacity to resist pH drops. Nitrifying bacteria don't work effectively below about 20 mg/L.
- Ammonium (NH4+)
- The ionized, much less toxic form of ammonia, dominant at lower pH.
- Biofilter
- The surfaces in a filter and tank where nitrifying bacteria live. A new biofilter takes about six to eight weeks to establish.
- Bioload
- The amount of waste produced in a tank, mainly from fish and food.
- Chloramine
- A disinfectant made from chlorine and ammonia used by many water utilities. It must be neutralized before tap water goes into an aquarium. Read more
- Consumer Confidence Report
- The annual water quality report that community water systems publish for their customers. Read more
- Cycling
- The process of establishing nitrifying bacteria in a new aquarium so ammonia and nitrite stay at zero.
- General hardness (GH)
- The amount of dissolved calcium and magnesium in water.
- Gravel vacuum
- A siphon tube used during water changes to lift debris from the substrate.
- New tank syndrome
- Fish deaths in a new tank from ammonia and nitrite building up before the biofilter is established.
- Nitrate
- The end product of nitrification, much less toxic than ammonia or nitrite, removed mainly by water changes and plants. Read more
- Nitrite
- The intermediate product of the nitrogen cycle, toxic to fish at levels as low as 0.10 mg/L. Read more
- Nitrogen cycle
- The bacterial conversion of ammonia to nitrite and then to nitrate in an aquarium. Read more
- pH
- A measure of how acidic or alkaline water is. Higher pH increases the toxic share of ammonia.
- Total ammonia nitrogen (TAN)
- The combined amount of un-ionized ammonia and ionized ammonium in water, as measured by most ammonia test kits, in mg/L or ppm. Read more
- Un-ionized ammonia (NH3)
- The highly toxic form of ammonia, about 100 times more toxic than ammonium. Its share of total ammonia rises with pH and temperature. Read more
- Water conditioner
- A product that neutralizes chlorine and, if labeled, chloramine in tap water for aquarium use.