Fish Keeping Reference

Aquarium Glossary — Every Term You Need to Know

125+ fish tank terms explained in plain language — from pH and the nitrogen cycle to KH, PAR, TDS, and everything in between. Bookmark this page as your go-to aquarium dictionary.

Nitrogen CyclepHKH / GHPARTDSIchCyclingDenitrification

A10 terms

Acclimatization: The process of slowly adjusting a fish to new water conditions (temperature, pH, salinity) before releasing it into a tank. Drip acclimatization over 30–60 minutes reduces stress and prevents osmotic shock.
Activated Carbon: A porous chemical filtration media that adsorbs dissolved organic compounds, medications, and odors from the water column. It must be replaced every 2–4 weeks as it becomes saturated.
Aeration: The process of increasing oxygen levels and releasing CO2 from aquarium water through water movement or air injection. Adequate aeration is essential for fish respiration and beneficial bacteria.
Airstone: A porous ceramic or stone diffuser attached to an air pump that breaks air into fine bubbles, increasing surface agitation and oxygen exchange. Also used to drive sponge filters.
Algae: Photosynthetic organisms that colonize aquarium surfaces. Green algae indicate good light; brown (diatom) algae occur in new tanks; black beard algae (BBA) signal CO2 fluctuations or excess nutrients.
Alkalinity: The water's ability to resist drops in pH, primarily measured as carbonate hardness (KH). High alkalinity (above 4 dKH) stabilizes pH, while low alkalinity leads to unstable "pH crashes."
Ammonia (NH3/NH4+): A toxic nitrogen compound produced by fish waste, uneaten food, and decaying matter. Ammonia levels above 0.25 ppm are harmful. It is the first compound processed in the nitrogen cycle.
Aquascape: The art and practice of arranging aquatic plants, rocks, substrate, and driftwood into an aesthetically designed underwater landscape. Styles include Dutch, Nature, Iwagumi, and Biotope.
Aufwuchs: A German term describing the community of algae, bacteria, invertebrates, and detritus that grows on hard surfaces (rocks, driftwood) in African rift lake biotopes. Many cichlids feed on aufwuchs naturally.
Anaerobic Zone: A region of substrate or filter media with little to no dissolved oxygen where anaerobic bacteria can convert nitrate to harmless nitrogen gas. Deep sand beds (4+ inches) intentionally create these zones.

B9 terms

Bacteria (Beneficial/Nitrifying): Colonies of Nitrosomonas and Nitrospira bacteria that convert toxic ammonia to nitrite and then nitrite to nitrate. They colonize filter media, substrate, and surfaces — the foundation of a healthy aquarium.
Bare Bottom: An aquarium setup with no substrate on the tank floor. Preferred in quarantine tanks, breeding tanks, and hospital tanks for easy cleaning and monitoring of fish droppings and food residue.
Biofilm: A thin layer of bacteria, algae, and organic matter that coats surfaces in an aquarium. Biofilm is a natural food source for shrimp, snails, and many bottom-dwelling fish.
Biological Filtration: The use of beneficial bacteria on filter media to break down ammonia and nitrite through the nitrogen cycle. This is the most critical filtration stage — never clean all bio-media at once.
Biotope: An aquarium that recreates the exact natural habitat of specific fish, using the correct substrate, water chemistry, plants, and tank mates found in that geographic location (e.g., Amazon blackwater).
Blackwater: Soft, acidic water stained brown by tannins from decaying leaves and driftwood. Natural blackwater environments (like the Rio Negro) have a pH of 4–6 and very low mineral content, ideal for tetras and bettas.
Breeding Cone: A ceramic or terracotta cone-shaped spawning site placed in the aquarium for egg-scatterers and egg-layers such as discus and angelfish. The smooth surface allows parents to lay and tend eggs easily.
Buffer: A chemical substance that resists changes in pH. Carbonate (KH) is the natural buffer in most freshwater tanks. Commercial buffers are used to stabilize pH in tanks with very soft water.
Buffering Capacity: The ability of water to neutralize acids and prevent pH swings. Directly related to KH — water with low KH has poor buffering capacity and is prone to dangerous pH crashes during the night.

C9 terms

Canister Filter: An external pressurized filter that draws water through multiple media chambers (mechanical, biological, chemical) before returning it to the tank. Ideal for larger tanks due to high flow rate and capacity.
Carbonate Hardness (KH): A measure of the concentration of carbonate and bicarbonate ions in water, expressed in degrees (dKH) or ppm. KH acts as the primary pH buffer — most freshwater fish need 3–10 dKH.
Chemical Filtration: The removal of dissolved pollutants through adsorption using media such as activated carbon, Purigen, zeolite, or phosphate remover. Used to polish water or remove specific compounds after medication.
Chloramine: A compound of chlorine and ammonia added to municipal tap water as a disinfectant. Unlike chlorine it does not evaporate — it must be neutralized with a dechlorinator that specifically targets chloramine.
Chlorine: A disinfectant added to tap water that is toxic to fish and beneficial bacteria. Chlorine dissipates with aeration over 24 hours or is instantly neutralized with sodium thiosulfate dechlorinators.
CO2 Diffuser: A device that dissolves pressurized carbon dioxide into fine bubbles for uptake by aquatic plants. Ceramic diffusers produce the finest mist. CO2 injection is essential for high-tech planted tanks.
Community Tank: An aquarium housing multiple compatible fish species of similar size and temperament. Successful community tanks consider water parameter overlap, territorial behavior, and feeding requirements.
Cycling (Nitrogen): The process of establishing a colony of beneficial bacteria in a new tank that converts ammonia to nitrite and nitrite to nitrate. A full cycle typically takes 4–8 weeks using ammonia dosing.
Columnaris: A bacterial infection (Flavobacterium columnare) appearing as white or gray patches, frayed fins, or cottony growths. Often misidentified as a fungus — it requires antibacterial treatment, not antifungal.

D7 terms

Dead Zone: An area of the aquarium with little or no water circulation where waste accumulates, oxygen depletes, and anaerobic bacteria produce toxic hydrogen sulfide. Powerheads and wavemakers eliminate dead zones.
Dechlorinator: A water conditioner that neutralizes chlorine and chloramine in tap water, making it safe for fish. Premium dechlorinators also detoxify ammonia, neutralize heavy metals, and protect fish slime coats.
Denitrification: The anaerobic bacterial process of converting nitrate (NO3) into harmless nitrogen gas (N2). Occurs in deep sand beds, anaerobic chambers, or refugiums with little oxygen.
Diatoms: Brown single-celled algae that coat substrate, glass, and decorations with a dusty brown film in newly set-up tanks or tanks with high silicate levels. They typically disappear on their own within weeks.
Driftwood: Natural wood used as hardscape in aquariums. It releases beneficial tannins that lower pH and soften water. New driftwood must be soaked for days to weeks to remove excess tannins and prevent buoyancy.
Drop Checker: A glass device filled with 4 dKH reference water and a pH indicator (bromo blue) that hangs inside the tank to visually monitor CO2 levels. Yellow = too much CO2; green = optimal; blue = too little.
Dwarf Species: Small fish or shrimp species suited to nano or community tanks due to their compact size (usually under 3 inches). Examples include dwarf gouramis, pygmy corydoras, and Neocardinia shrimp.

E3 terms

Eutrophication: A condition of excessive nutrient enrichment (nitrate, phosphate) that causes explosive algae growth, depletes oxygen as algae decompose, and can crash the entire tank ecosystem.
Evaporation: Water loss from the aquarium surface due to heat and air movement. As water evaporates, mineral concentrations rise (TDS increases). Top-offs should use RO or dechlorinated water, not tank water.
External Filter: A canister or sump filter located outside the aquarium connected by inlet and outlet pipes. External filters allow large media volumes and are virtually silent, making them popular for large display tanks.

F6 terms

Filter Media: Materials inside a filter that perform mechanical (sponge, filter floss), biological (ceramic rings, bio-balls), or chemical (activated carbon, Purigen) filtration. Layer in the correct sequence for best results.
Fin Rot: A bacterial or fungal infection causing progressive deterioration of fins, starting at the edges and moving toward the body. Caused by poor water quality, stress, or injury. Treated with water changes and antibiotics.
Flashing: A behavior where fish rapidly rub themselves against surfaces (substrate, decor). It indicates irritation from parasites (ich, flukes), gill damage, or poor water quality and requires immediate investigation.
Fry: Newly hatched or very young fish that are still at the early larval or juvenile stage. Fry require specialized fine foods (infusoria, egg yolk, microworms) and protection from adult fish.
Full Spectrum Light: An aquarium light that emits wavelengths across the full visible spectrum (400–700 nm), supporting plant photosynthesis and rendering fish colors accurately. Look for lights with a CRI above 90.
Flow Rate: The volume of water a pump or filter moves per hour, measured in liters per hour (LPH) or gallons per hour (GPH). A general rule is to filter the full tank volume 4–10 times per hour.

G4 terms

General Hardness (GH): A measurement of calcium and magnesium ion concentration in water, expressed in degrees (dGH) or ppm. GH affects fish osmoregulation, plant health, and shrimp molting success.
Gill Flukes: Microscopic parasitic flatworms (Dactylogyrus) that attach to fish gills, causing rapid breathing, flashing, and lethargy. Treated with praziquantel or formalin-based medications.
Gravel Vac: A siphon device used during water changes to vacuum debris, uneaten food, and waste from the substrate. Regular gravel vacuuming prevents nitrate buildup and hydrogen sulfide in deep gravel beds.
Green Water: A bright green cloud in tank water caused by a bloom of free-floating single-celled algae (phytoplankton). While harmless to fish, it is eliminated by UV sterilizers, blackout periods, or water changes.

H5 terms

Hardscape: The non-living structural elements of an aquascape including rocks, stones, driftwood, and roots. Hardscape defines the layout and flow of the aquascape design before plants are added.
Heavy Metal Toxicity: Poisoning from copper, lead, zinc, or iron in tap water or leaching decor. Copper is especially toxic to invertebrates at even trace levels. Premium dechlorinators and RO water prevent heavy metal issues.
Herbivore: A fish that primarily eats plant material including algae, vegetables, and aquatic plants. Examples include plecos, goldfish, and silver dollars. Herbivores may damage live plants in planted tanks.
HOB Filter: Hang-On-Back filter — a compact, easy-to-maintain power filter that hangs on the tank rim. Water is drawn up a tube, passed through media, and returned via a waterfall. Ideal for tanks up to 200 liters.
Hospital Tank: A separate bare-bottom quarantine aquarium used to isolate, observe, and treat sick fish without exposing the main display tank to disease or medications that harm beneficial bacteria.

I3 terms

Ich (Ichthyophthirius): One of the most common fish diseases, presenting as white spots resembling grains of salt on fins and body. Caused by the protozoan parasite Ichthyophthirius multifiliis. Treated by raising temperature and adding salt or medication.
Internal Filter: A submersible filter unit that operates inside the aquarium, typically driven by an impeller. Less powerful than external canisters but practical for small tanks, quarantine setups, and hospital tanks.
Invertebrate: Animals without a backbone kept in aquariums including shrimp, snails, crabs, crayfish, and clams. Invertebrates are highly sensitive to copper and many medications — always check labels before dosing.

J2 terms

Java Fern (Microsorum pteropus): A hardy, slow-growing aquatic fern that attaches to rocks and driftwood rather than being planted in substrate. It tolerates low light and a wide range of water parameters, making it ideal for beginners.
Java Moss (Taxiphyllum barbieri): A versatile, fast-growing aquatic moss that clings to any surface and thrives in low to medium light without CO2. It provides shelter for fry and shrimp, and is widely used in breeding setups.

K2 terms

KH (Carbonate Hardness): See Carbonate Hardness. KH is a measure of carbonate and bicarbonate ions that stabilize pH. Freshwater tanks typically need 3–8 dKH; African cichlid tanks benefit from 8–15 dKH.
Killifish: A diverse family of small, colorful egg-laying fish found in temporary water bodies worldwide. Many species are annual killifish that lay eggs in mud that survive the dry season — eggs can be stored in peat.

L4 terms

L-Number Plecos: A designation system for undescribed plecostomus catfish (family Loricariidae) where each species is given an L-number (e.g., L046 Zebra Pleco) until formally described. Many are highly sought-after by collectors.
Lateral Line: A sensory organ running along the sides of fish that detects vibration, pressure changes, and water movement. It helps fish navigate, find food, and detect predators in murky water.
Livebearer: Fish species that give birth to free-swimming young rather than laying eggs. Common livebearers include guppies, mollies, platies, and swordtails. They are among the easiest fish to breed in captivity.
Low-Tech Tank: A planted aquarium that relies on low to moderate lighting, no injected CO2, and a nutrient-rich substrate. Suited to slow-growing, low-demand plants like Anubias, Java fern, and Crypts.

M5 terms

Mechanical Filtration: Physical removal of suspended particles (waste, uneaten food, debris) from tank water using filter sponges, filter floss, or filter socks. The first stage of filtration — must be cleaned regularly to prevent clogging.
Mini Cycle: A temporary spike in ammonia and nitrite that occurs after cleaning filter media, removing a large portion of substrate, adding new fish, or treating with antibiotics that kill beneficial bacteria.
Molting (Shrimp): The process by which shrimp shed their exoskeleton to grow a new, larger one. During molting shrimp are extremely vulnerable and must not be disturbed. Adequate calcium (GH) is critical for successful molts.
Moss Ball (Marimo): A dense ball of Aegagropila linnaei algae native to cold lakes in Japan and Iceland. Marimo balls slowly rotate toward light, absorb nutrients, and provide grazing surfaces for shrimp without contributing to algae problems.
Multiplex (Multi-Tank System): A centralized fish room setup where multiple tanks share a common sump or filtration system, allowing water quality to be managed at scale. Common in fish farms and dedicated hobbyist fish rooms.

N6 terms

Nano Tank: A small aquarium typically under 40 liters (10 gallons). Nano tanks require more frequent water changes, precise stocking, and careful monitoring as water parameters fluctuate rapidly in small volumes.
New Tank Syndrome: A condition in newly set-up aquariums where ammonia and nitrite spike due to the absence of established beneficial bacteria, causing fish stress or death. Prevented by fishless cycling before adding fish.
Nitrate (NO3): The final relatively low-toxicity product of the nitrogen cycle produced by Nitrospira bacteria from nitrite. Nitrate accumulates over time and is managed through regular water changes. Keep below 20 ppm for sensitive species.
Nitrite (NO2): An intermediate compound in the nitrogen cycle that is highly toxic to fish, interfering with oxygen transport in the blood. Nitrite spikes occur during the initial cycling phase and mini cycles.
Nitrogen Cycle: The biological process converting toxic ammonia (fish waste) → nitrite (Nitrosomonas bacteria) → nitrate (Nitrospira bacteria). Establishing this cycle is the most important step in setting up any aquarium.
NTD (Neon Tetra Disease): A fatal parasitic infection (Pleistophora hyphessobryconis) causing color loss, bloating, and curved spine in neon tetras. There is no effective treatment — infected fish should be removed immediately.

O4 terms

Omnivore: A fish that eats both plant matter and animal proteins. Most common aquarium fish are omnivores (tetras, guppies, angelfish) and benefit from a varied diet of flakes, pellets, live or frozen foods.
Osmosis: The movement of water across a semi-permeable membrane from an area of lower solute concentration to higher concentration. Fish use osmosis to regulate water and salt balance — changes in TDS cause osmotic stress.
Over-Stocking: Adding more fish than the tank filtration and volume can support, resulting in elevated ammonia/nitrate, oxygen depletion, increased disease, and aggression. Follow the guideline of 1 inch of fish per gallon as a starting point.
Oxygen Depletion: A critical drop in dissolved oxygen caused by overstocking, algae crashes, high temperatures, or poor surface agitation. Fish gasp at the surface during oxygen depletion — immediately increase aeration.

P9 terms

PAR (Photosynthetically Active Radiation): A measurement of light energy available for plant photosynthesis in the 400–700 nm wavelength range, expressed in micromoles per square meter per second (µmol/m²/s). Low-tech plants need 20–50 PAR; high-tech planted tanks need 50–150+ PAR.
Peat: Decomposed sphagnum moss used as a substrate additive or filter media to soften water, lower pH, and release tannins. Useful for blackwater biotope setups and breeding soft-water species.
pH: A logarithmic scale (0–14) measuring the acidity or alkalinity of water. pH 7 is neutral; below 7 is acidic; above 7 is alkaline. Most freshwater fish thrive between pH 6.5–7.5. A change of 1 pH unit = 10× change in acidity.
Photoperiod: The duration of daily light exposure in the aquarium. Most planted tanks benefit from 8–10 hours of light per day. Excessive photoperiod (12+ hours) promotes algae growth without increasing plant growth.
Planted Tank: An aquarium that incorporates live aquatic plants as a central element. Planted tanks provide oxygen, nutrient export, hiding places for fish, and natural water filtration when well established.
Powerhead: A submersible water circulation pump used to create water flow, eliminate dead zones, and improve oxygenation. Often used in conjunction with undergravel filters or to create current for rheophilic fish.
Pre-filter: A sponge or mechanical filter fitted over an inlet tube or powerhead to catch large debris before it reaches the main filter, protecting the impeller and extending service intervals for primary filtration.
Protein Skimmer: A device that uses air bubbles to remove dissolved organic compounds (proteins, waste) before they break down into ammonia. Essential equipment for marine reef tanks; rarely used in freshwater.
Purigen: A premium synthetic polymer filter media by Seachem that removes nitrogenous waste, tannins, and impurities, producing exceptionally clear water. Purigen can be recharged with bleach solution when exhausted.

Q2 terms

Quarantine Tank: A separate aquarium used to isolate new fish for 2–4 weeks before adding them to the main display tank, allowing observation for disease and parasite treatment without contaminating the main system.
Quick-Release Coupler: Inline valves fitted to canister filter hoses that allow the filter to be disconnected for maintenance without draining hoses or causing water spillage. A standard feature on most modern canister filters.

R5 terms

Ram Cichlid (Mikrogeophagus ramirezi): A small, colorful dwarf cichlid from soft, acidic South American waters. Rams are delicate — they require warm water (27–30°C), low pH (6.0–7.0), and pristine water quality to thrive and breed.
Refugium: A separate compartment connected to the main tank (usually in the sump) where macroalgae grow to export nutrients, and live organisms like copepods, amphipods, and worms reproduce safely.
Remineralization: The process of adding minerals back to RO/distilled water using mineral salts (e.g., Seachem Equilibrium, Ca/Mg supplements) to reach the target GH and KH required for specific fish or shrimp.
Reverse Osmosis (RO): A water purification process that forces tap water through a semi-permeable membrane, removing up to 99% of dissolved minerals, chlorine, heavy metals, and contaminants. RO water has near-zero TDS.
Root Tabs: Fertilizer capsules pressed into the substrate near plant roots to supply iron, potassium, and micronutrients directly to root-feeding plants such as Crypts, Amazon swords, and Vallisneria.

S7 terms

Sand Substrate: Fine-grained substrate (0.5–1.5 mm) that provides a natural look and suits bottom-dwelling fish like corydoras and loaches. Sand must be stirred or planted regularly to prevent compaction and anaerobic pockets.
Softwater: Water with low GH (0–8 ppm or 0–4 dGH) and low mineral content. Natural softwater environments include the Amazon basin. Soft water is preferred by discus, angelfish, tetras, and many shrimp species.
Sponge Filter: A simple, air-driven filter that draws water through a sponge for mechanical and biological filtration. Inexpensive, gentle, and safe for fry — the preferred filter for breeding tanks, shrimp tanks, and quarantine setups.
Stock Level: The number of fish relative to tank volume and filtration capacity. Overstocking leads to water quality issues and stress. A practical baseline is 1 cm of adult fish body length per 2 liters of water.
Surface Agitation: Disruption of the water surface by filter output, powerheads, or airstones, which promotes gas exchange — releasing CO2 and absorbing oxygen. Essential for all fish; must be balanced in high-tech CO2 planted tanks.
Substrate: The material covering the bottom of an aquarium, including gravel, sand, soil, and crushed coral. Substrate choice affects water chemistry, plant growth, fish behavior, and tank aesthetics.
Specific Gravity: A measurement of water density relative to pure water, used in marine and brackish aquariums to measure salinity. Freshwater = 1.000; marine reef tanks = 1.025–1.026. Measured with a hydrometer or refractometer.

T6 terms

Tank Cycling: Establishing the nitrogen cycle in a new aquarium by growing beneficial bacteria colonies before adding fish. Fishless cycling with pure ammonia is the safest method, typically taking 4–8 weeks.
Tannins: Organic compounds leached from driftwood, botanicals, and peat that turn aquarium water amber-brown, lower pH, and soften water. Tannins have mild antimicrobial and antifungal properties beneficial to blackwater species.
TDS (Total Dissolved Solids): A measurement of all dissolved substances in water (minerals, salts, organics) in parts per million (ppm) or mg/L. TDS is important for shrimp (optimal 150–250 ppm for Neocaridina) and discus (80–120 ppm).
Thermal Shock: Rapid temperature change that causes stress, immune suppression, and potentially death in fish. Always match new water to within 1°C of the tank temperature before adding it during water changes.
Thermometer: An essential instrument for monitoring aquarium temperature. Digital thermometers with probes are most accurate. Temperature fluctuations greater than 2°C per day stress fish and promote disease.
Top-Off: Adding water to the aquarium to replace volume lost through evaporation. Top-offs should use pure RO water or dechlorinated fresh water — never saltwater — to avoid gradual mineral concentration buildup.

U2 terms

UV Sterilizer: A device that exposes aquarium water to ultraviolet light as it passes through a chamber, killing free-floating bacteria, algae, and parasites. UV sterilizers control green water and reduce disease transmission but do not eliminate established infections.
Undergravel Filter (UGF): A filter plate positioned under the substrate that draws water through the gravel using uplift tubes and air pumps, turning the substrate itself into biological filter media. Now largely replaced by modern canister and sponge filters.

V3 terms

Vallisneria: A fast-growing background plant with long ribbon-like leaves that propagates via runners across the substrate. Vallisneria tolerates hard, alkaline water and bright light, making it ideal for cichlid and goldfish tanks.
Venturi Effect: The drop in fluid pressure created when water flows through a constriction, used in protein skimmers and CO2 reactors to draw air into water flow. Also used in some filter designs to passively inject CO2.
Velvet (Oodinium): A protozoan parasitic infection causing a gold or rust-colored dust on the body and fins, similar to ich but finer. Fish flash and may show rapid breathing. Treated with copper-based medications or acriflavine.

W5 terms

Water Change: The replacement of a portion of tank water (typically 20–30% weekly) with fresh conditioned water to dilute nitrate, replenish minerals, and remove dissolved organic compounds. The single most important maintenance task.
Water Hardness: A combined measure of dissolved minerals in water, split into General Hardness (GH = Ca/Mg) and Carbonate Hardness (KH = buffers). Hardness affects fish osmoregulation, breeding success, and plant nutrient uptake.
Water Movement: The circulation and flow of water throughout the aquarium created by filters, powerheads, and wavemakers. Adequate movement distributes heat, nutrients, and oxygen while eliminating dead zones.
Wavemaker: A submersible pump that creates rhythmic or randomized wave-like water movement in the aquarium. Wavemakers simulate natural currents, improve oxygenation, and benefit rheophilic species that prefer strong flow.
Wet/Dry Filter (Trickle Filter): A sump-based filter where water trickles over bio-media exposed to air (the "dry" zone), maximizing nitrification by providing both water and oxygen to beneficial bacteria. Highly efficient for heavily stocked tanks.

X2 terms

Xiphophorus (Swordtail/Platy Genus): A genus of livebearing freshwater fish native to Central America including swordtails (X. hellerii) and platies (X. maculatus). They are beginner-friendly, peaceful, and available in dozens of color morphs.
Xenia: A genus of soft coral in marine reef tanks known for its pulsating, rhythmic pumping motion. While visually captivating, Xenia can grow aggressively and overtake other corals in the reef tank.

Y2 terms

Yield (Biological Filter Capacity): The maximum ammonia processing rate a mature filter's bacterial colony can handle before the tank shows a positive ammonia reading. Adding fish faster than yield can increase triggers mini cycles.
Yellow Tang: A vibrant yellow surgeonfish (Zebrasoma flavescens) from Hawaiian reefs, one of the most popular marine aquarium fish. It grazes algae actively and requires a tank of 200+ liters with excellent water quality.

Z3 terms

Zeolite: A natural mineral used as a chemical filter media to absorb ammonia from water through ion exchange. Useful as an emergency measure in new tanks before beneficial bacteria establish, but must be recharged or replaced regularly.
Zero Ammonia Target: The goal of maintaining ammonia at 0 ppm in an established aquarium at all times. Any detectable ammonia above 0.25 ppm signals a problem — overfeeding, filter failure, overstocking, or a dead fish.
Zooplankton: Microscopic aquatic animals including copepods, daphnia, rotifers, and cyclops that serve as live food for fry and small fish. Culturing zooplankton at home provides highly nutritious live food on demand.

125+

Terms Defined

Letters Covered

A-Z

Complete Alphabet

Free

No Sign-Up Needed

Start Your Aquarium Journey

Now that you know the terms, it is time to put them to use. Browse our fish catalog, explore in-depth care guides, or read our expert blog — all free from 4848 One Shop.

Browse Fish Products Read Care Blog 90-Topic Care Guides