Reduction is a chemical reaction in which a substance gains electrons, the paired counterpart to oxidation. Together these two processes underlie ORP measurements and various natural water quality dynamics within a reef tank.

Lithium is a trace element present in natural seawater in very small amounts, with a still poorly understood role in reef tank biology. It’s rarely tested or dosed directly, typically appearing only as one line item on a comprehensive ICP report.

Element accumulation refers to the gradual buildup of a trace or major element in aquarium water beyond its natural or intended range, often from over-dosing or an imbalanced salt mix. Left unchecked, it can become harmful to sensitive corals and invertebrates.

Temperature is a fundamental water parameter affecting metabolic rate, oxygen solubility, and overall livestock health in a reef tank. Most reef tanks target a stable range closely mirroring natural tropical reef conditions year-round.

Chlorine is a chemical disinfectant commonly added to municipal tap water to control bacteria and pathogens. While effective for drinking water safety, it’s toxic to fish, invertebrates, and beneficial bacteria, so it must be fully removed before that water is used in a reef tank.

Kalkwasser, German for lime water, is a calcium hydroxide solution used to simultaneously raise calcium and alkalinity while buffering pH. It’s a traditional, cost-effective supplementation method still popular in the reef keeping hobby.

Reef chemistry refers to the broad study and management of water parameters that support coral health, from major elements like calcium to trace elements and nutrients. It’s the foundational knowledge base behind successful reef keeping.

Organic carbon refers to carbon-containing compounds from living or once-living sources, present in aquarium water as dissolved waste and decaying matter. It’s central to both natural bacterial processes and deliberate carbon dosing for nutrient export.

A TDS meter is a handheld device that measures total dissolved solids in water by reading its electrical conductivity. Reef keepers use it primarily to verify RODI purification equipment is producing adequately pure water.

Chloramine is a compound of chlorine and ammonia used by many municipal water systems as a more stable disinfectant than chlorine alone. Because it’s harder to remove and toxic to aquatic life, source water needs proper filtration before it’s used in a reef tank.

Bicarbonate is one of the two key ions, along with carbonate, that make up a reef aquarium’s alkalinity. Together they help buffer pH and supply the raw material corals use to build their calcium carbonate skeletons.

A cleanup crew is a group of snails, hermit crabs, and other grazing invertebrates added to a reef tank to consume algae, detritus, and leftover food. They play a hands-on role in nutrient control, working alongside filtration to help keep the tank clean.

Tissue growth refers to the expansion of a coral’s living soft tissue, distinct from but closely related to skeletal growth beneath it. It reflects overall coral nutrition, health, and favorable environmental conditions over time.

Bioavailable nutrition refers to coral foods and supplements formulated for direct, efficient absorption, minimizing the need for digestion or processing. These highly accessible nutrients, like amino acids and dissolved proteins, help support fast, effective uptake for corals and other reef organisms.

Reef nutrition refers to the broad practice of meeting the dietary needs of corals, fish, and invertebrates through appropriate feeding and supplementation. It’s foundational to coral growth, coloration, and overall tank health, alongside stable water chemistry.

ORP, or oxidation reduction potential, measures the overall oxidizing or reducing capacity of aquarium water, reflecting its ability to break down organic contaminants. It’s a useful indicator of overall water quality and stability.

Element consumption refers to the rate at which corals and other organisms draw a specific trace or major element from the water. Understanding consumption for key elements helps reef keepers dose accurately rather than relying on generic guidelines.

Chromium is a trace element present in natural seawater at very low concentrations. Like several other trace elements, its precise biological role in coral health isn’t fully understood, but it’s tracked through ICP testing as part of a tank’s overall mineral profile.

Live sand is aquarium sand that comes populated with beneficial bacteria and microfauna, offering an immediate biological boost similar to live rock. It’s commonly used to help jump-start a new tank’s nitrogen cycle.

Test kits are chemical reagent-based products used to measure specific water parameters like calcium, alkalinity, and nitrate in a reef tank. They form the foundation of informed dosing and troubleshooting decisions for every reef keeper.