Bacteria that requires oxygen to survive.

Simple rootless plants that grow in bodies of water in relative proportion to the amount of nutrients available. Algae produce oxygen (photosynthesize) with sunlight (natural or artificial) and use oxygen (respire) during the night hours. Some types of algae are beneficial to aquatic environments while others can be considered a nuisance.

a system of filtration that relies upon the controlled growth of turf algae in a separate compartment attached to the main display that is regularly harvested as a primary means of nutrient export. This system is becoming more accepted by hobbyists as a workable solution

Water tested that is measuring above a neutral pH (7.1-14.0).

The capacity of a system to resist a downward change in pH. Also referred to as carbonate hardness. The recommended range is 8-10 dkh.

A compound of Nitrogen and Hydrogen, formed in the anaerobic decomposition of organic matter. Ammonia can also be added to public water sources to bond with chlorine to form chloramines.

A calcium based sand or substrate using in saltwater aquariums.

An organism capable of synthesizing (making) its own food from inorganic substances. These organisms use light or chemical energy.

A term referring to all animal and plant life in a system. Primarily fish and decomposing organic matter.

The use of media to grow colonies of aerobic or anaerobic bacteria to facilitate the removal of dissolved waste in the form of ammonia and nitrite and conversion to nitrate.

The process in which zooxanthellae expel themselves from the tissue of the corals they are living in causing a lack of pigmentation in the coral. Usually associated with high water temperatures or because of excessive lighting.

Polychaete worms that primarily consuming detritus. Once thought to be harmful to reef aquariums, most now believe they are beneficial to a reef tank.

A chemical filter media used to adsorb odors, dissolved organics, pollutants, medications and discolorations.

An encrusting algae that utilizes calcium to grow. This is a desirable algae and growth demonstrates a healthy aquarium. Typically, purple, pink or red in color.

Live rock that has gone through the curing process (see Curing Live Rock).