Deciphering Hobby Talk: Acronyms and Commonly Used Terms

We've all been there - the daunting reply to a thread in which every other word is an acronym or a term that everyone else but you seems to...
  1. confusion.jpg

    We've all been there - the daunting reply to a thread in which every other word is an acronym or a term that everyone else but you seems to understand. Here is an attempt to clear up and define some more of the commonly used terms in the hobby and on the forums. Ive searched through the forums and combined some of the older acronym lists that have been buried and included some of the more current terminology as well as chemical formulas, coral names, people, vendors and treatments that are commonly seen on Reef2Reef. This alphabetical list should make it much easier to navigate the lingo for beginners and seasoned veterans alike!


    A / Amp – Ampere. A measure of electricity
    AA - Amino Acid
    ABT - Atlantic blue Tang
    AC - Activated Carbon
    AC - Alternating Current
    Acan Lord – Acanthastrea coral, scientific name: Micromussa lordhowensis
    Acro- Acropora coral

    AcroASD (1).jpg

    AEFW - Acropora Eating Flatworms
    AGA - All-Glass Aquarium
    AIO – All in One – typically in reference to an aquarium
    Alk – Alkalinity
    Alkalinity - The measure of carbonate (HCO3) and bicarbonate (H2CO3) in solution
    Algae Reactor – A media reactor filled with macro-algae (generally Chaetomorpha) and wrapped in LED lights in order to speed growth and nutrient removal. This is essentially a type of refugium
    Apex – A popular aquarium controller made by Neptune Systems
    Aquacultured – A coral/fish that has been grown in captivity, rather than in the ocean
    ASW – Artificial Sea Water
    ATC – Automatic Temperature Compensation
    ATO - Auto Top Off
    ATS - Algae Turf Scrubber
    Aussie – Slang for coral gathered in Australian waters


    BA - Bubble algae (Valonia ventricosa)


    BB - Bare Bottom
    BBT – Bare Bottom Tank
    BC – BattleCorals (.com)
    Bean / Beananimal – A drain set up with three stand pipes, one at full siphon, one open channel and an emergency drain
    Big 3 – Refers to common parameters of a reef tank: Calcium, Alkalinity & Magnesium
    Biofilter – Refers to the bacteria that converts ammonia into nitrite/nitrate/nitrogen in the aquarium
    Biological Filtration – Refers to the nitrifying bacteria within an aquarium that breaks down waste into less harmful by products. Can also refer to macroalgae filtration, deep sand beds, carbon dosing and/or biopellets.
    BioWheel – A cylinder of filter media that is generally a part of a hang on back filter to host bacteria
    Blasto – Blastomussa. Blastomussa is a genus of large polyp stony corals. Some members of this genus are sometimes found in reef aquariums
    Bleaching – Refers to the loss of coloring pigments in corals, generally due to undesirable lighting or nutrient levels
    BLC – Blue Legged Hermit Crab
    BOGO - Buy One, Get One (Free). A term used in sales of livestock
    Bonded Pair – Refers to a pair of fish that have paired off into a male/female pair. These may not yet be of breeding age
    BR – Base Rock
    BRS – Bulk Reef Supply
    BTA – Bubble Tip Anemone
    BTU - British Thermal Unit


    C2C – Coast to Coast Overflow
    Ca – Calcium
    CaCl2 – Calcium Chloride
    CaCO3 – Calcium Carbonate
    Ca(OH)2 – Calcium Hydroxide
    CaRx – Calcium Reactor
    Cali – California
    CB – Cornbred a well-known coral vendor/propagator
    CBB - Copper Band Butterfly


    CC - Counter Current
    CC - Crushed Coral
    CFL - Compact Fluorescent Lamp
    CH – Carbonate Hardness
    Chaeto – Chaetomorpha. A macro algae
    CL - Closed Loop
    CL - Craigslist
    CO2 - Carbon Dioxide
    Colony – An aggregate of individual organisms, generally used to refer to a number of coral polyps
    Conductivity – A measure of a solutions ability to conduct electricity. Generally used as a fast and reliable way to measure the ionic content in the solution. The conductivity of reef tank water is not equal to the salinity of the same water.
    Cooking – Typically a slang term used to describe a method of soaking rock to leech off any unwanted or undesirable compounds (such as Phosphates) or detritus. It generally does not refer to literally cooking rocks.
    CP – Chloroquine Phosphate, a medication used to treat Ich and Velvet
    Crypto – See Ich
    Cu - Copper
    CUC - Clean Up Crew
    CWC - Continuous water change
    Cyano – Cyanobacteria. Cyanobacteria are a group of photosynthetic, nitrogen fixing bacteria that live in a wide variety of moist soils and water
    Cycle – Typically refers to establishing the nitrogen cycle in conjunction with starting a new aquarium. We establish the nitrogen cycle, not end it


    DC - Direct Current
    DD - Downdraft
    DD - Diver's Den - a specialize subset from that sells WYSIWYG items that go through a heightened quarantine and acclimation. Often are harder to find fish/corals/invertebrates
    DE - Double Ended
    Detritus - Dead particulate organic material (as opposed to dissolved organic material). It typically includes the bodies or fragments of dead organisms as well as fecal material. Detritus of aquatic ecosystems is organic material suspended in water and piles up on seabed floors
    DFS - Drs. Foster and Smith
    DI – Deionization
    DI water - Deionized water
    Digi – Montipora digitata
    Dinos – Dinoflagellates
    Dirty – Generally referring to high nutrient levels in an aquarium
    DIY - Do It Yourself
    dKH - German Degrees of Hardness, units used in alkalinity measurements
    DO - Dissolved Oxygen
    DOC - Dissolved Organic Carbon
    Dory – Reference to the Disney movie “Finding Nemo”, Dory is a Paracanthurus hepatus – commonly called a hippo tang, blue tang, or palette surgeonfish
    DSB - Deep Sand Bed
    DT - Display tank
    Durso – A type of drain system utilizing two stand pipes, one at full siphon and the other with an open channel.


    EB – Electronic Ballast
    EC – End Cap
    ESV – A commonly used brand of Alkalinity and Calcium supplement
    ETA - Estimated Time of Arrival
    Eurobrace – A glass or acrylic brace that is attached to the top of an aquarium to structurally reinforce it



    FB – Facebook
    Fe - Iron
    Feeler – A thread where the originator is asking for opinions on a selling price for an item
    FO - Fish Only
    Foot – Generally a term used in respect to anemones, this is the basal disc, or part that attaches to the rock or substrate
    FOWLR - Fish Only With Live Rock
    Frag - Fragment (a small part of a coral colony removed in order to grow another colony)
    Frag Plug – A piece of ceramic, plastic or stone used in coral propagation. Frags are mounted on frag plugs
    FTS - Full Tank Shot
    FTW- For the win
    Fuge - Refugium
    FW – Freshwater
    FWD – Freshwater Dip
    FWE - Flat Worm Exit
    FWIW -For what its worth


    G- Gallon (ex. 60g)
    GAC - Granular Activated Carbon
    GBP – Green Button Polyps
    GBR – Great Barrier Reef
    GBTA - Green Bubble Tip anemone
    GFCI - Ground Fault Circuit Interrupter
    GFI - Ground Fault Interrupter
    GFO - Granular Ferric Oxide
    GHA - Green Hair Algae


    Ghost Overflow – A style of overflow that has a minimal footprint inside of the aquarium with a larger overflow box on the exterior of the aquarium that houses the drain standpipes
    GPD - Gallons per Day
    GPH - Gallons per Hour
    Group Buy – Generally a large number of people making a large order at one time to gain some discount or shipping benefit from a vendor
    GSM -Gold Stripe Maroon Clownfish
    GSP - Green Star Polyps
    Guest – An organism that is hosted by another organism. Example: Clownfish are guests to the anemone.


    H2O – Chemical formula for water
    H202 – Chemical formula for Hydrogen Peroxide
    HA - Hair Algae
    HAB – Harmful Algae Bloom
    Herbie – A drain setup with only one stand pipe, typically with a hole present to prevent a full siphon
    HID - High intensity discharge
    High Light – A generic term generally referring to the amount of lighting a coral needs to survive. High light is vaguely defined as a PAR measurement of 300+.
    Hitch hiker – A term used for an organism that was introduced to the tank inadvertently, generally by live rock or coral frag plug
    HITH – Hole in the Head Disease
    HLLE – Head and Lateral Line Disease


    HO - High Output
    HOB - Hang on Back
    Host - An organism that harbors a parasitic, a mutual, or a commensal symbiont, typically providing nourishment and shelter. Example: Anemones host clownfish
    Hosting – The act of harboring a guest, generally to the mutual benefit of both the Guest and the Host. Anemones are hosting my clownfish pair.
    HOT - Hang On Tank
    HQI - Mercury (Hg) Quartz Iodide


    I / I2 - Iodine
    Ich / Ick – Cryptocaryon irritans is a species of ciliates that parasitizes marine fish, causing marine white spot disease or marine ich


    ICP – Inductive Coupled Plasma. A type of mass spectrometry which is capable of detecting metals and several non-metals at very low levels. This is achieved by ionizing the sample with inductively coupled plasma and then sorting the resulting ions by mass spectrometry
    IME - In my experience
    IMHO - In my humble opinion
    IMO- In my opinion
    IO - Instant Ocean
    IR - Infrared
    IW - In Wall


    JF – Jason Fox, a well-known coral vendor/propagator


    K – Kelvin
    Kalk – Kalkwasser. A German term for calcium hydroxide or saturated limewater. A method of supplementing alkalinity and calcium consumption in an aquarium
    KISS – Keep It Simple Stupid
    KWh - Kilowatt-Hour


    L – Liter
    LA – LiveAquaria (.com)
    lb(s) - Pounds
    LED - Light emitting diodes
    Lepto – Leptoseris coral
    LFS - Local fish store
    LHS – Local hardware store
    LMB – Lawnmower Blenny
    LNS – Low Nutrient System
    Lobo – Lobophyllia. Lobophyllia, commonly called lobed brain coral or lobo coral, is a genus of large polyp stony corals
    Low Light – A generic term generally referring to the amount of lighting a coral needs to survive. Low light is vaguely defined as a PAR measurement of 100 or less
    LPS - Large polyp stony corals that have large and soft polyps
    LR - Live Rock
    LS - Live Sand
    LTA - Long Tentacle Anemone


    Lymph – Short for Lymphocystis, a common viral infection in marine fish


    MACNA - Marine Aquaria Conference of North America
    Maricultured – Generally a coral that has been grown on a coral farm in the ocean
    Macro – Macroalgae. Typically this refers to algae that form larger and more complex growth forms. Example: Chaetomorpha
    Marine Ick – See Ich
    Marine Velvet - Velvet disease, also called gold dust disease, is a fish disease caused by dinoflagellate parasites of the genus Piscinoodinium, which gives the fish a dusty, slimy look.
    Marine White Spot Disease – See Ich
    MASNA - Marine Aquarium Societies of North America
    MB – Magnetic Ballast
    MD – Marine Depot (.com)
    Mechanical Filtration – A method of capturing floating debris from the water and removing it before it breaks down further. Generally these are filter socks and filter pads.
    meq/L - Micro-equalities per Liter
    Mg or Mag – Magnesium
    mg/L – Milligram per liter
    MH - Metal Halide light
    Milli - Acropora millipora


    Mini-Cycle – This is not a thing. See Cycle
    Mixed Reef – Generally refers to an aquarium that contains SPS, LPS and Soft corals
    MJ - Maxijet
    Mr. Saltwater Tank – Mark Callahan, a YouTube personality with a web series devoted to the reefing hobby
    MS – Mass Spectrometry
    MV – Mercury Vapor
    Mysis – A small freshwater shrimp that is widely used as frozen food for marine aquariums


    N2 – Nitrogen
    Na – Sodium
    NACO3 – Sodium Carbonate
    NaOH – Sodium Hydroxide
    Nano Tank – A small aquarium, generally between 5 and 20 gallons in size
    Nemo – A reference to the Disney movie “Finding Nemo”, Nemo is an Amphiprion ocellaris, commonly called a clownfish
    Nems- anemones
    Newbie – A person new to the hobby
    NH3 - Ammonia
    NNR - Natural Nitrate Reduction
    NO - Normal Output
    NO2 - Nitrite
    NO3 – Nitrate
    NOPOX - NO3PO4X is a Red Sea additive used for controlling nutrients.
    NPS - Non Photosynthetic
    NSW – Natural Sea Water
    NTS – New Tank Syndrome


    O2 – Oxygen
    OC – Open Channel. A drain tube that allows both water and air to enter.
    OC – Original Collector
    One Inch Per Gallon – An antiquated adage that are certain total inches of fish would be compatible with the total gallon size in an aquarium. This ‘rule’ is widely believed to be incorrect
    ORA- Oceans, Reefs, and Aquariums
    ORP - Oxygen Redox Potential
    OTS – Old Tank Syndrome


    PA – Premium Aquatics
    PAR - Photosynthetic Active Radiation, a unit used in measuring light output
    Paly – Palythoa coral
    PB – Pulse Ballast
    PBT-Powder Blue Tang
    PC - Power Compact
    PE – Polyp Extension (in relation to corals)
    PE – Piscine Energetics (food company)
    pH - The measure of the ratio of H+ to OH- ions in solution. Typical pH range in a reef tank is 7.8 – 8.2
    PH – Power Head
    Pico Tank – A small aquarium, generally less than 5 gallons in size
    Pods – Refers to a variety of small crustaceans, generally copepods and amphipods

    Tigriopus californicusMale.jpg

    PO4 - Phosphate
    POTM - Picture of the month
    PP - Per polyp
    PPM - Parts per Million
    PPT - Parts per Thousand
    Prazi – Prazipro, a commonly used deworming medication to treat flukes
    Profilux – A popular aquarium controller made by GHL
    PS – Protein Skimmer
    PUR- Photosyntheically Usable Radiation, a unit associated with light measurement
    PVC - Poly Vinyl Chloride


    QM – Quality Marine
    QT - Quarantine Tank


    R2R - Reef to reef (.com)
    RAP – Reef-A-Palooza, a large reefing conference
    RBTA - Rose Bubble tip anemone
    RC - Reef Crystals
    RC – ReefCentral (.com)
    RDSB - Remote Deep Sand Bed
    Redfield Ratio - The atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton and throughout the deep oceans. This empirically developed stoichiometric ratio was originally found to be C : N : P = 117:14:1
    RHF – Randy Holmes-Farley, Reef2Reef resident chemist
    Rics – Ricordea
    Rimless – An aquarium that has no plastic or eurobracing around the top of the tank.
    RK / RKL – ReefKeeper, a popular aquarium controller
    RO water - Reverse osmosis water
    RODI - Reverse Osmosis, Deionized
    ROX – A specific type of activated carbon used to remove impurities from the water. Generally considered an aggressive type of carbon
    RR - Reef Ready (aquarium)
    RR – Reef Raft (corals)
    RTN - Rapid Tissue Necrosis


    RUGF – Reverse Under Gravel Filter


    Sanjay – Refers to Sanjay Joshi, a well-known authority on reef lighting
    SE - Single Ended
    SG - Specific Gravity
    Shrooms – Mushrooms
    Si – Silicon
    SiO2 – Silicon Dioxide
    Socks – Filter socks, a type of mechanical filtration
    Softy – Corals that lack a rigid calcium skeleton. Typically zoanthids, mushrooms, leathers and xenias
    SPS - Small polyp stony coral
    SSB - Shallow Sand Bed
    Starphire – A low iron glass made by PPG
    STN - Slow Tissue Necrosis
    Stoichiometry - The calculation of relative quantities of reactants and products in chemical reactions.
    SW - Salt Water / Sea Water


    T5 / T8 – Reference to the size of fluorescent bulbs for aquarium lighting
    Tank – An Aquarium
    TBS – Tampa Bay Saltwater (.com)
    TDS - Total Dissolved Solids
    Texas Trash – See Green Button Polyps. Often seen as an undesirable and invasive coral
    TFC - Thin Film Composite
    TIC – Total Inorganic Carbon
    TOTM - Tank of the month
    Tort – Acropora tortuosa
    Triton Test – An ICP analysis that shows a variety of metal and non-metal components in a sample of aquarium water. A sample of aquarium water is mailed to the testing lab and results are generally received in 7-10 days


    TTM – Tank Transfer Method. A method of quarantining fish to prevent and cure some common parasites
    Trachy – Trachyphyllia
    Two Part – Refers to an additive system using 2 or more components to supplement calcium and alkalinity. Often can supplement magnesium as a “third” part
    Tyree – Named after Steve Tyree, a well-known coral vendor/propagator


    UGF – Under Gravel Filter
    ULNS - Ultra Low Nutrient System
    UPS – Uninterruptible Power Supply
    UV - Ultra Violet


    V - Volt
    VHO - Very High Output (fluorescent light)
    VSV – Vodka, Sugar and/or Vinegar


    W - Watts
    WC - Water Change
    Wellso – Wellsophyllia


    WPG – Watts per Gallon
    WTB – Want to Buy
    WTS – Want to Sell
    WTT – Want to Trade
    WQ – Water Quality
    WWC – World Wide Corals
    WYSIWG - What you see is what you get


    YWG-Yellow Watchman Goby


    Z&P - Zoanthids and Palythoa
    Zoas - Zoanthid Coral
    Zoos – Slang term for Zoanthids


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    About Author

    Kris Fulk has been keeping marine tanks for over a decade, and has been keeping aquariums for the better part of the last three decades. His current tank is a 100 gallon SPS tank running on the ZeoVit method. His real profession is a research chemist at a large pharmaceutical company, but he has degrees in marine biology (botany focus) and biotechnology. He describes himself as a "professional learner" and considers himself walking proof of Murphy's Law. Kris resides in Western Michigan with his wife, two children and two mastiffs.
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