Aquarium glossary

Acclimatisation

The process of gradual adaptation of fish and invertebrates to the water parameters of the new aquarium. Skipping acclimatization can cause fatal osmotic shock.

Activated carbon

The most used chemical filter in aquariums. Removes colours, odors, drug residues and organic compounds from water.

Aiptasia

Infesting anemones that arrive with live rock. They reproduce rapidly and sting nearby corals. One of the most hated parasites in the reef.

Algae in aquarium

Algae are photosynthetic organisms that proliferate when light and nutrients are in excess. Some are beneficial (coralline algae), most are unwanted.

Alkalinity

Alkalinity is synonymous with KH in the aquarium context. Indicates the buffer capacity of the water against pH variations.

Alkalinity in marine aquariums (dKH)

The buffer capacity of sea water. Corals consume carbonates to build their skeleton. Critical parameter in the reef.

Allelopathy (chemical warfare between corals)

The release of toxic substances by corals and invertebrates to compete with their neighbors. An often underestimated factor in reef design.

Aluminium in the aquarium

Metal contaminant that should not be present in aquarium water. Even in trace amounts it can damage corals and invertebrates.

Ammonia (NH3/NH4+)

Ammonia is the first product of organic decomposition in the aquarium. In non-ionised form (NH3) it is toxic even at very low concentrations.

Aquarium automation

The set of devices that automate daily management: ATO, dosing pumps, controllers, automatic feeders and remote monitoring.

Aquarium chiller

Device that cools the aquarium water. Indispensable in summer for reef aquariums where the temperature must remain below 27 degrees.

Aquarium controller

Electronic device that automatically monitors and controls aquarium parameters: temperature, pH, ORP, level, pumps and lighting.

Aquarium cycling

The initial period in which a new aquarium develops the bacterial colony necessary to sustain life. It lasts 3-6 weeks and should never be skipped.

Aquarium lighting

Lighting determines the growth of corals and plants. Too much light favours algae. Too little kills photosynthetic organisms.

Aquarium temperature probe and thermometer

Tools for monitoring water temperature. There are immersion thermometers, digital ones with probe, and probes connected to controllers.

Aragonite

Crystalline form of calcium carbonate. It makes up the skeleton of corals, living sand and the substrate of calcium reactors.

Artemia (brine shrimp)

Small saltwater crustaceans used as live food. Newly hatched nauplii are ideal food for fry and small fish.

ATO (Auto Top Off)

Automatic evaporated water refill system. Maintains a constant level in the aquarium by adding osmosis water automatically.

Automated tests (Trident, KH Guardian)

Devices that automatically measure water parameters at programmed intervals. The next level of reef monitoring.

Automatic dosing (dosing pump)

System of peristaltic pumps that automatically dose additives into the aquarium at programmed intervals. Fundamental to maintain stable parameters in the reef.

Balling method

Balling is the most widespread method for integrating calcium, KH and magnesium into a reef aquarium. It is based on three separate solutions dosed in proportion.

Barium

Trace element present in sea water. It is consumed by corals and sponges. Its role is still little understood but must be monitored with ICP.

Bioload (biological load)

The total amount of organic waste produced by living organisms in an aquarium. Excessive bioload overloads the filter and leads to the accumulation of toxic substances.

Biological filter

The heart of the filtration system. It hosts bacteria that make the nitrogen cycle possible by transforming toxic substances into less dangerous compounds.

Blennidae (Blenniidae)

Bottom fish with a friendly and curious behaviour. They perch on rocks and observe the environment. Many species are herbivorous and reef safe.

Boron

Trace element present in sea water. Important for the metabolism of corals and calcareous algae. It is monitored via ICP analysis.

Butterflyfish (Chaetodontidae)

Marine fish with bright colours and an elongated snout. Most are not reef safe because they feed on coral polyps.

Calcium (Ca)

Calcium is the fundamental building block for the growth of corals and invertebrates. In the reefs it is consumed continuously and must be constantly replenished.

Calcium hydroxide (slaked lime)

The chemical compound behind kalkwasser. Provides calcium and KH simultaneously raising pH and precipitating phosphates.

Calcium reactor

The calcium reactor dissolves calcareous material (ARM, fossil coral) with CO2 to release calcium and KH into the aquarium water.

Calcium reactor media

Limestone substrate dissolved by CO2 in the reactor. ARM and fossil coral are the standard choices.

Calcium-magnesium ratio

In marine aquariums the ratio between calcium and magnesium must be balanced. Magnesium allows calcium to remain in solution without precipitating.

Cardinal fish (Apogonidae)

Peaceful and easy to breed marine fish. Oral incubators: The male holds the eggs in his mouth until they hatch.

Chemical filter

Uses adsorbent materials to remove dissolved substances from water that mechanical and biological filtration cannot eliminate.

Chlorine and chloramines

Disinfectants present in tap water. Deadly for fish, invertebrates and filter bacteria. They must always be neutralized before use.

Choice of feed

The quality of food influences the health, colours and longevity of fish. Varying between dry, frozen and live is the best strategy.

Circulation pump

Creates water circulation inside the aquarium. Fundamental in marine aquariums for the health of corals and in all aquariums to distribute oxygen and nutrients.

Circulation pump (powerhead)

Submersible pump that creates current in the aquarium. In marine aquariums it is essential for corals.

Clean-up fish and invertebrates

Organisms that help keep the aquarium clean by eating algae, debris and food scraps. A complement to maintenance, not a replacement.

Clownfish (Amphiprion)

Among the most iconic and resistant marine fish. They live in symbiosis with anemones but in the aquarium they also adapt without them. Ideal for those starting with the reef.

Cobalt

Essential trace element in minimal traces. Component of vitamin B12. Important for bacteria and algae, monitored with ICP.

Compatibility between fish

Not all fish can live together. Choosing aquarium companions requires consideration of temperament, size, parameters and diet.

Copper (Cu)

Copper is extremely toxic to invertebrates and corals even at very low concentrations. It serves only as a drug treatment for some fish diseases.

Coral feeding

Corals feed on light (zooxanthellae) and particulate food (phytoplankton, zooplankton, amino acids). Direct feeding improves growth and colours.

Coralline algae

Pink-purple calcareous algae that encrust rocks and glass in marine aquariums. Sign of good health of the aquarium and natural competitors of unwanted algae.

Crabs in the reef

Some crabs are useful scavengers in the reef. Others are predators that attack corals and fish at night. The choice must be made with caution.

CUC (Clean Up Crew)

The set of scavenger invertebrates that keep a marine aquarium clean: snails, hermit crabs, crabs, starfish, urchins, shrimps.

Cyanoacrylate glue for aquarium

Super glue gel used to glue corals, mosses and plants to rocks and wood. Safe for aquariums, polymerizes on contact with water.

Cyanobacteria (cyano)

Cyanobacteria are photosynthetic organisms that form red-brown slimy mats in the aquarium. They are not algae but bacteria capable of photosynthesis.

Cycling (nitrogen cycle)

Cycling is the process by which the colony of nitrifying bacteria is established in a new aquarium. Without complete cycling the fish die.

Denitrification

The biological process that converts nitrates into nitrogen gas. It occurs in anaerobic conditions (without oxygen) within live rock, deep substrates and special filters.

Diatoms

Brown unicellular algae that appear in new aquariums. They form a brown film on glass, substrate and decorations. They disappear on their own as they mature.

Dinoflagellates (dino)

Dinoflagellates are single-celled organisms that can infest a marine aquarium with a mucilaginous brown coating. They often appear in aquariums with ultralow nutrients.

Dip for corals

Preventive or curative bath for corals before introduction into the aquarium. Removes hidden parasites, nudibranchs, flatworms and Aiptasia.

Dissolved oxygen

The amount of oxygen present in the water. Essential for the respiration of fish, corals and filter bacteria.

Dosage of organic carbon (vodka/vinegar)

Dosed vinegar or vodka to feed denitrifying bacteria and reduce nitrates without water changes.

Dropsy (ascites)

Condition in which the fish swells with raised scales (pine cone appearance). Often a sign of kidney failure or serious bacterial infection.

DSB (Deep Sand Bed)

Deep sand bed (10-15 cm) creating anaerobic zones for denitrification. A natural method to remove nitrates.

Epoxy putty for aquarium

Two-component moldable used to create structures, glue rocks and modify the hardscape underwater. Reef safe after hardening.

Evaporation and refilling (ATO)

Aquarium water evaporates continuously. Topping up must be done with fresh water (RO) because the salt does not evaporate. ATO systems automate this.

Filamentous algae

Green algae that form tufts and filaments on rocks, plants and decorations. Sign of imbalance between light and nutrients.

Fish diseases

Fish get sick due to stress, wrong parameters, bacteria, parasites or viruses. Recognizing symptoms early makes the difference between an easy treatment and a fatality.

Fish feeding

One of the most important aspects of managing an aquarium. Proper nutrition keeps fish healthy and reduces water pollution.

Fluoride in the aquarium

Naturally present in sea water. In the aquarium it mainly comes from synthetic salt and tap water. Toxic in excess.

Fragging (coral propagation)

The technique of cutting fragments from a mother coral to create new colonies. It allows you to multiply corals without taking them from nature.

GFO (Granular Ferric Oxide)

Antiphosphate resin based on iron oxide. The most widespread method for controlling phosphates in marine aquariums.

Gobies (Gobiidae)

Small bottom fish perfect for the reef. Some species sift through the sand, others live in symbiosis with pistol shrimp.

Gravel vacuum (siphon)

Wide bell tube used to vacuum debris from the substrate during water changes. The most used maintenance tool.

Gyre pump (laminar flow)

Laminar flow circulation pump that moves water along the entire length of the aquarium. More efficient than traditional powerheads.

Hardscape

The set of rocks and wood that form the supporting structure of the aquatic landscape. The foundation on which to build aquascaping.

Heater

Maintains the water temperature constant at the desired value. Indispensable for tropical aquariums in environments where the ambient temperature drops below 24 degrees.

hospital aquarium

A separate aquarium dedicated to the treatment of sick fish. Allows you to use medications without contaminating the main aquarium.

How to choose the right aquarium

Choosing the volume, shape and material of the aquarium is the first step. The larger the aquarium, the easier it is to manage.

Ich (white spot disease)

The most common disease of aquarium fish. Caused by a parasitic protozoan that manifests itself as white dots on the body and fins.

ICP-OES analysis

Inductively Coupled Plasma (ICP) analysis very precisely measures dozens of elements in aquarium water with a single sample mailed.

ICP-OES protocol

Laboratory analysis that measures dozens of elements in aquarium water with very high precision. The most complete diagnostic tool for the reef.

Iodine (I)

Iodine is essential for the moulting of crustaceans and for the health of some soft corals. It is consumed quickly and must be replenished in aquariums with many invertebrates.

Ion exchange (DI) resins

Final stage of the RO/DI system. They remove the last traces of impurities from osmosis water, bringing the TDS to zero.

Iron (Fe)

Iron is an essential micronutrient for aquatic plants. The deficiency causes pale leaves with green veins. In marine aquariums it is less critical.

Kalkwasser (lime water)

Kalkwasser is a saturated solution of calcium hydroxide used to supplement calcium and KH simultaneously. An ancient but still effective method.

KH (carbonate hardness)

KH measures the ability of water to resist changes in pH. In practice it indicates how stable the system is from a chemical point of view.

Lead in aquarium

Highly toxic heavy metal. It should never be present. Deadly for invertebrates and fish even at very low concentrations.

Light spectrum

The colour composition of the light emitted by the lamp. Each wavelength has different effects on plants, corals and colour perception.

Lighting timer and controller

Device that turns the aquarium lights on and off at scheduled times. Fundamental for a constant photoperiod and for the health of plants and corals.

Lionfish (Pterois)

Predatory marine fish with poisonous spines. Beautiful but not reef safe: eats shrimp, crabs and small fish.

Lithium in the aquarium

Trace element present in natural sea water. Its biological role in the aquarium is little known. It is monitored with ICP.

Live rock

Limestone rocks colonised by bacteria, sponges, microorganisms and small invertebrates. In marine aquariums they are the main substrate for biological filtration.

LPS corals (Large Polyp Stony)

Hard corals with large polyps. More resistant than SPS, with showy tentacles and intense colours. Also suitable for those starting out in the marine world.

Magnesium (Mg)

Magnesium stabilises the balance between calcium and KH preventing spontaneous precipitation. Without adequate magnesium the Balling method does not work.

Magnesium chloride

The salt used to supplement magnesium in reef aquariums. Component of the third solution of the Balling method.

Management of starfish in the aquarium

Starfish are fascinating but challenging. Serpentine stars are the most suitable for the reef.

Mandarin fish (Synchiropus splendidus)

One of the most beautiful and colourful marine fish. Difficult to feed: eats only live copepods. Requires mature aquariums with abundant microfauna.

Manganese

Essential microelement for aquatic plants and for some enzymatic processes in corals. Required in minimal traces.

Mangroves in aquarium

Mangrove seedlings grown in the sump or aquarium with submerged roots and emerged leaves. They absorb nitrates and add a unique natural element.

Marine invertebrates

The set of corals, anemones, shrimps, crabs, snails, stars and urchins that populate a reef aquarium. Often more demanding than fish.

Mechanical filter

Removes suspended particles from the water: debris, uneaten food, plant residues. It makes the water clear and protects the biological filter.

Mediterranean aquarium

Cold sea water aquarium that replicates the Mediterranean ecosystem. A fascinating alternative to the tropical reef with local fauna.

Molybdenum

Trace element essential for nitrogen metabolism in plants and bacteria. Required in microscopic quantities.

Nano aquarium

small volume aquariums, generally under 60 litres. They require more attention because the parameters oscillate more rapidly in small volumes.

Nano reef

Small volume marine aquarium (30-80 litres) with corals and invertebrates. A fascinating challenge that requires compact equipment and frequent maintenance.

Nickel in the aquarium

Contaminating heavy metal. Even in small quantities it can damage corals. Its presence almost always indicates a problem to be solved.

Nitrates (NO3)

Nitrates are the end product of the nitrogen cycle. Less toxic than ammonia and nitrites but harmful if they accumulate over time.

Nitrification

The bacterial process that converts toxic ammonia to nitrites and then to nitrates. It is the crucial half of the nitrogen cycle in any aquarium.

Nitrites (NO2)

Nitrites are the intermediate product of the nitrogen cycle. Like ammonia they must be at zero in a mature aquarium.

Nitrogen cycle

The biological process that transforms toxic fish waste into less dangerous substances. Without a mature nitrogen cycle no aquarium can function.

Ocellaris clownfish

The most widespread clownfish in aquariums, made famous by the film Nemo. Easy, resistant and available in many captive bred varieties.

Ornamental shrimp

Freshwater and marine crustaceans farmed for their bright colours. Neocaridina and Caridina are among the most popular inhabitants of nano aquariums.

ORP (redox potential)

ORP measures the oxidizing power of water in millivolts. A high ORP indicates clean, well-oxygenated water. A low ORP indicates accumulation of organic substances.

Overflow

The system that transports water from the aquarium to the sump by gravity. It can be internal (weir box) or external (hang on). Determines the maximum flow rate of the system.

Ozone in the aquarium

Powerful oxidizing gas used to sterilize water and improve its clarity. Effective but dangerous: must be used with ORP controller and activated carbon.

PAR (Photosynthetically Active Radiation)

PAR measures the amount of light that can be used for photosynthesis. It is the most important parameter for positioning corals and aquatic plants.

Peristaltic pump (how it works)

The mechanism behind dosing pumps. A rotor compresses a hose, pushing the liquid precisely.

pH

The pH indicates how acidic or alkaline the water is on a scale from 0 to 14. For aquariums the ideal value depends on the type of aquarium and the species hosted.

pH probe for aquarium

Electronic probe for continuous pH monitoring. Connected to a controller it allows automatic alarms and control of the CO2 or calcium reactor.

Phosphates (PO4)

Phosphates are nutrients that in excess fuel algae growth. On the reef they must be kept very low. In planted freshwater aquariums they are needed for the plants.

Photoperiod

The daily duration of lighting in the aquarium. It influences the photosynthesis of plants and zooxanthellae, the behaviour of fish and the growth of algae.

Phytoplankton

Unicellular microalgae cultivated as food for filter-feeding corals, bivalves, zooplankton and invertebrate larvae.

Planarians

Flatworms that infest freshwater and marine aquariums. In freshwater aquariums they threaten shrimp colonies. In marine aquariums they attack corals.

Potassium (K)

Potassium is an often overlooked trace element in marine aquariums. It contributes to the colour of corals, especially intense reds and purples.

Protein skimmer

The skimmer removes organic compounds from seawater before they decompose. It is considered the most important filter for a reef aquarium.

Quarantine

The quarantine is a separate aquarium where new arrivals (fish, corals, plants) are kept under observation before entering the main aquarium.

Quarantine protocol for marine fish

Quarantine is even more critical in marine aquariums than in freshwater aquariums. A comprehensive protocol includes observation, therapeutic copper, and praziquantel.

Red Sea Reefer (complete aquariums)

Complete reef aquarium systems (tank + sump + mobile + system) ready for use. The most popular choice for those who want a reef without building it from scratch.

Reef aquarium controller

Electronic control unit that monitors and controls all the parameters of the aquarium. The brain of reef automation.

Reef integration programs

Complete dosing systems that provide calcium, KH, magnesium and trace elements in a balanced way. Each brand has its own philosophy and products.

Reef safe

Indicates that a product, a fish or an invertebrate is compatible with a reef aquarium without damaging corals, anemones and other invertebrates.

Refractometer

Optical instrument for measuring the salinity of sea water. More precise than the hydrometer, it is considered the minimum standard for a reef aquarium.

Refugium

The refugium is a section of the sump where macroalgae (typically Chaetomorpha) grow with dedicated lighting. It is used to export nitrates and phosphates naturally.

Refugium and remote DSB

A compartment of the sump dedicated to natural filtration with macroalgae, deep sand and microfauna. Separate the process from the display for added security.

Refugium macroalgae

Marine algae grown in the refugium to absorb nitrates and phosphates naturally. A biological alternative to chemical filters.

Return pump

Pump that transports water from the sump to the main aquarium. Correct sizing is essential for the circulation and functioning of the system.

Reverse osmosis (RO) water

Water purified by reverse osmosis. The basis for preparing synthetic seawater and for water changes in freshwater aquariums when pure water is needed.

Reverse osmosis (RO/RODI)

The reverse osmosis system purifies mains water by removing chlorine, heavy metals, silicates and other substances. Produces basic water for each aquarium.

Reverse osmosis membrane

The heart of the RO system. A semi-permeable membrane that removes 95-98% of impurities from tap water.

Roller mat (roller filter)

Automatic mechanical filtration system that replaces filter socks. A roll of non-woven fabric filters the water and advances automatically.

Rotifers

Microscopic planktonic animals used as first food for fish larvae and marine invertebrates. Essential for marine breeding.

RTN and STN (coral necrosis)

Rapid (RTN) or slow (STN) tissue loss in corals. Causes include stress, unstable parameters, bacterial infections and contamination.

Salinity

Salinity indicates the total concentration of salts dissolved in water. It is measured in PSU, ppt or by specific gravity (SG).

Sea anemones

Stinging invertebrates that host clownfish in symbiosis. Beautiful but demanding: they require intense light, perfect water and a mature aquarium.

Sea urchins

Voracious herbivores that control algae in the reef. Useful but can damage corals with thorns and move fragments.

Silicates (SiO2)

Silicates fuel the growth of diatoms (brown algae). They are common in new aquariums and can enter from unfiltered mains water.

Snails in the aquarium

Gastropods useful as scavengers and algae eaters. Some species are introduced voluntarily, others arrive as stowaways on the plants.

Sodium

The most abundant element in sea water after chlorine. It contributes to the salinity and osmotic balance of aquatic organisms.

Sodium bicarbonate in aquarium

Economical product for raising KH and pH in freshwater aquariums. Basic ingredient of Balling solution for KH In marine aquariums.

Soft corals

Corals without rigid calcareous skeleton. They are the easiest to maintain in marine aquariums, with bright colours and rapid growth.

Specific gravity (SG)

Specific gravity is an alternative way to measure salinity. Indicates the ratio between the density of salt water and that of pure water.

SPS (Small Polyp Stony) corals

Hard corals with small polyps. They are the builders of coral reefs and represent the greatest challenge in marine aquariums.

Starfish in the aquarium

Fascinating invertebrates but often difficult to keep in captivity. Serpentine stars are the most suitable for the reef.

Strontium (Sr)

Strontium is a trace element that contributes to the calcification of corals. It is consumed slowly and must be replenished in intensive reef aquariums.

Substrate (aquarium bed)

The material that covers the bottom of the aquarium. It influences aesthetics, water chemistry, plant growth and fish well-being.

Sulfates

Ions naturally present in sea and fresh water. In marine aquariums they are the third most concentrated component after chloride and sodium.

Sump

The sump is an accessory aquarium located under the main aquarium. It houses the technical equipment (skimmer, heater, rise pump) and increases the total volume of water.

Synthetic sea salt

Mixture of mineral salts that recreates the composition of natural sea water. It dissolves in osmosis water to obtain salt water for the aquarium.

Tang (surgeon fish)

Herbivorous marine fish with a compressed body and bright colours. Essential for algae control in the reef but require large aquariums.

Tank Score

The Tank Score is the health score of the aquarium from 0 to 100 calculated by Coralia Lab's artificial intelligence. It analyzes all the parameters to give you an immediate picture.

Temperature

Temperature influences every biological process in the aquarium: metabolism, dissolved oxygen, bacterial activity, growth of corals and plants.

Tin (Sn) in aquariums

Contaminating heavy metal. It should not be present in the aquarium water. Toxic for corals and invertebrates.

Triton method and other no-water-change systems

Reef management methods that aim to eliminate or drastically reduce water changes, replacing them with regular element dosing and ICP analysis.

Tunicates (sea squirts)

Brightly coloured filter-feeding marine invertebrates. They are often found on live rock. Some are beautiful, others haunting.

UV sterilizer

Device that exposes water to ultraviolet rays to kill pathogenic bacteria, free-phase parasites and suspended unicellular algae.

Valonia (bubble algae)

Spherical green algae growing on rocks in marine aquariums. Unsightly and difficult to remove. Emerald crab is the best organic remedy.

Vanadium in aquarium

Trace element present in sea water in traces. Limited but monitored biological role in ICP analyzes as a quality indicator.

Velvet (Oodinium/Velvet Disease)

Parasitic disease that coats fish in a golden or gray powder. More dangerous than stroke because it is often diagnosed too late.

Water change

Changing the water is the most important maintenance in aquariums. Removes accumulated waste products and restores consumed trace elements.

Water test

Analysis kit to measure the chemical and physical parameters of water. They are the eyes of the aquarist: without tests you are sailing blind.

Wavemaker (wave generator)

Device that creates a wave movement in the aquarium simulating natural marine conditions. Different from traditional powerheads.

Wrasse (Labridae)

Colourful and active marine fish. Many species are reef safe and useful for controlling parasites and weeds.

Zeolite

Natural porous mineral used as a chemical filter. Removes ammonia from fresh water. In marine aquariums the ZEOvit system is a complete aquarium management method.

Zinc in the aquarium

Essential trace element in minimal traces for enzymes and biological processes. In excess it becomes toxic, especially for invertebrates and corals.

Zooxanthellae

Symbiotic microalgae that live in coral tissues. They provide energy through photosynthesis in exchange for protection and nutrients.