Dissolved oxygen is the amount of oxygen gas present in aquarium water, essential for fish, invertebrates, and beneficial bacteria to survive and function. Adequate flow and surface agitation are key to keeping levels consistently high.

Supplementation refers to the practice of adding elements, compounds, or nutrients to a reef tank to replenish what natural consumption depletes over time. It spans major parameter dosing, trace elements, and nutritional additives.

Ion exchange is a water treatment process that swaps unwanted dissolved ions for more benign ones, commonly used in RO/DI systems and specialized resins. It’s a key mechanism behind purifying source water and certain nutrient export methods.

Chemical filtration uses media like activated carbon and GFO to adsorb dissolved organic compounds, toxins, and excess nutrients from aquarium water. It’s one of three core filtration categories, working alongside mechanical and biological filtration to maintain overall water quality.

Barium is a trace element present in natural seawater in very small quantities. While its exact biological role in corals isn’t fully understood, it’s monitored through ICP testing as part of a broader picture of trace element balance in a reef aquarium.

A quarantine tank is a separate, smaller aquarium used to observe and treat new fish or coral before introducing them to a main display. It’s a key preventive tool for keeping pests and disease out of an established reef tank.

Nutrient import refers to all the ways nutrients enter a reef tank, primarily through feeding, livestock waste, and source water. Understanding nutrient import helps reef keepers manage the other side of the nutrient balance equation.

The Balling Method is a dosing technique that uses separate solutions of calcium, alkalinity, and trace elements to replenish what corals consume, without mixing them together and risking precipitation. It’s a precise, scalable way for reef keepers to maintain stable major parameters in growing systems.

Dinoflagellates are single-celled organisms that can form brown, tan, or rust-colored mucus-like outbreaks in a reef tank, often in low-nutrient systems. Unlike many other nuisance algae, dinoflagellates can be genuinely challenging and stubborn to fully eliminate once they become established in a system.

Sulfur is an element present in seawater and reef tank organic matter, involved in various biological processes and certain bacterial denitrification methods. It’s rarely tested directly but plays a background role in several reef keeping practices.

Chelation is a chemical process in which an organic molecule binds tightly to a metal ion, keeping it dissolved and bioavailable rather than allowing it to precipitate out of the water. It’s commonly used in trace element supplements to improve stability and uptake.

Nutrient uptake refers to the process by which corals, algae, and bacteria absorb dissolved nutrients like nitrate and phosphate from aquarium water. It’s a key natural mechanism working alongside active nutrient export methods.

A reef aquarium is a marine tank specifically designed to house and support live coral alongside fish and other invertebrates. It requires more specialized equipment and closer attention to water chemistry than a standard fish-only tank.

Iron is a trace element that supports certain algae and coral pigmentation processes, though it’s more commonly discussed in reef keeping for its role in GFO media. Supplementation is generally approached conservatively and based on testing.

A dosing pump is a piece of equipment that automatically delivers precise, scheduled amounts of liquid supplements like calcium and alkalinity into a reef tank. It removes the need for manual daily dosing, improving consistency and convenience.

Base rock is the dry, structural rock used to build the physical foundation of a reef aquascape. Typically made from calcium carbonate material, it starts out biologically inert but gradually becomes colonized by beneficial bacteria and coralline algae as the tank matures.

TDS, or total dissolved solids, measures the combined concentration of all dissolved minerals and impurities in water. Reef keepers use TDS readings primarily to verify that RODI purification equipment is performing effectively before use.

A chiller is a piece of equipment that actively cools aquarium water to maintain a stable, appropriate temperature. It’s especially important in warm climates or systems with significant heat output from lighting and pumps, where water can otherwise run too warm.

Ionic balance refers to the proper ratio of major ions in reef tank water, closely mirroring natural seawater’s composition. Maintaining this balance supports stable water chemistry and healthy biological processes throughout the tank.

Nutrient limitation occurs when available nutrients like nitrate or phosphate become too scarce to support healthy coral growth and function. It’s the opposite extreme of nutrient excess, and can be just as harmful to reef tank health.