A water change is the routine process of removing a portion of tank water and replacing it with freshly mixed saltwater, diluting accumulated waste and replenishing depleted elements. It’s one of the most fundamental reef maintenance practices.

Zinc is a trace element that supports enzymatic function and immune health in corals and fish, present naturally in seawater at very low concentrations. It’s typically replenished passively through water changes rather than dosed directly.

RODI water is water that has passed through both a reverse osmosis membrane and a deionization resin, removing nearly all dissolved impurities. It’s the gold-standard source water most reef keepers rely on for mixing saltwater and topping off.

Wet skimming is a protein skimmer operating style that produces a wetter, more liquid foam with less air contact time, removing a larger volume of less concentrated skimmate. It’s a less aggressive nutrient export approach than dry skimming.

Reverse osmosis is a water purification process that forces tap water through a semipermeable membrane to remove dissolved impurities. It’s the first major stage in producing the pure source water reef tanks require.

A wave maker is a powerhead or pump designed to create randomized or pulsing water movement within a reef tank, mimicking natural ocean current patterns. Strong, varied flow benefits coral health and detritus control.

Freshly mixed saltwater is newly prepared synthetic seawater made by dissolving salt mix into RO/DI water, used for water changes and top-off. Proper mixing and matching parameters to the display tank are essential before use.

A refractometer is a precision optical instrument used to measure salinity by detecting how light bends passing through a water sample. It’s generally considered more accurate than a hydrometer for reef tank salinity testing.

Water testing is the practice of regularly measuring a reef tank’s key parameters using test kits, meters, or ICP analysis to monitor water quality. It’s a foundational habit that informs virtually every other reef keeping decision.

A frag rack is a perforated stand or tray used to hold multiple frag plugs upright and organized within a reef tank or dedicated frag system. It keeps growing coral fragments stable, visible, and easy to manage.

Specific gravity is a measurement comparing the density of aquarium water to pure freshwater, commonly used to express salinity. Reef tanks typically target a specific gravity range around 1.025 to 1.026, checked regularly with a hydrometer or refractometer.

Skeletal growth refers to the ongoing process by which scleractinian corals build and expand their calcium carbonate skeleton over time. It’s directly supported by stable calcium, alkalinity, and magnesium levels, and reflects overall coral health.

Zoanthids are colonial soft corals known for their vibrant colors and hardy, fast-growing nature, forming mat-like colonies of small polyps. They’re a popular choice for both beginner and experienced reef keepers alike, valued for covering rockwork.

Photosynthesis is the process by which the symbiotic algae living within coral tissues convert light into energy. This relationship provides corals with a significant portion of the energy they need for growth, metabolism, and overall health.

Zooxanthellae are microscopic algae that live within the tissues of many reef-building corals. Through photosynthesis, these algae produce energy that helps support coral growth, metabolism, coloration, and overall health.

Zooplankton are microscopic animals that drift through the water column and serve as one of the most important natural food sources for corals and many other reef inhabitants. Rich in proteins, amino acids, fatty acids, and other nutrients, zooplankton plays a vital role in reef nutrition.

Vitamins are essential organic compounds that support coral health, growth, metabolism, and overall biological function. Although required in small amounts, vitamins play a critical role in helping corals maintain normal cellular processes and respond to environmental stress.

Trace elements are minerals that corals and other reef inhabitants require in very small amounts to support growth, coloration, metabolism, and overall health. Although needed in tiny quantities, these elements play essential roles in many biological processes within a reef aquarium.

Torch corals are popular LPS corals known for their long flowing tentacles, vibrant colors, and dramatic movement in the aquarium. Through a combination of photosynthesis and feeding, torch corals obtain the energy and nutrients needed for growth, coloration, and overall health.

Target feeding is a coral feeding method where food is delivered directly to a specific coral using a feeding tool such as a pipette, turkey baster, or syringe. This approach allows reef keepers to provide nutrition precisely where it is needed while minimizing food distribution throughout the aquarium.