The Reef Keepers Glossary


An Internet Guide to Reefkeeping Abbreviations, Terminology and Shorthand.
I'm sure you've seen them, and perhaps they have left you puzzled. Don't worry, its not our own secret language. Well, then again maybe it is. As with any hobby on the internet, you're bound to run into shorthand, terms, and abbreviations that leave you at sea. I won't be covering the standard chit-chat stuff like LOL, BRB, HaX0r, or any extremely deep abbreviations like , CaCl2 (Calcium Chloride). I'll just be dealing with Internet Reef-Speak. I hope the table below helps you a bit.
ABS Acrylonitrile Butadiene Styrene, a plastic used in the housing for lights
AC Activated Carbon
  Acro Acropora - A popular type of stony coral
AFM Aquarium Fish Monthly, a magazine
  Alk Alkalinity
B-Ionic The brand name for a line of aquarium supplements from ESV corporation
  Bleach(ed) When a coral turns white due to its loss of Zooxanthellae. Typically fatal especially in stony corals
Blue Legs A type of small hermit crab
Buffer Chemical typically used to help in controlling Alkalinity balance
  Ca Calcium
  CBS Coral Banded Shrimp
Cl Chlorine
CO2 Carbon Dioxide
  CPVC Chlorinated PolyVinylChloride - plumbing pipes typically used in households and for plumbing reef tanks
Cu Copper
DD skimmer Down Draft skimmer
DI DeIonized - a type of tap water purification
  DIY Do It Yourself
  dKH Alkalinity
  Dosing Adding chemicals of any nature to a reef tank (ie. Dosing Calcium and Alkalinity supplements)
DLSB Deep Live Sand Bed
  DSB Deep Sand Bed
E. Quad Entacmaea quadricolor, bubble tipped anemone
FO Fish Only - A tank with just fish, no corals or live rock
  FOWLR Fish Only With Live Rock - A tank with fish and live rock. No corals
  Frag A cutting of a coral that has or is being propagated
  FW Fresh Water
GAC Granular Activated Carbon - used in mechanical filtration
GPH Gallons Per Hour - typically dealing with pumps or overflows
GPM Gallons Per Minute - typically dealing with pumps or overflows
  GSP Green Star Polyps
HD Home Depot (A U.S. major hardware store)
  Kalk Kalkwasser - Lime Water - Used for calcium/alkalinity supplementation and balance
  KH Alkalinity Level
  LFS Local Fish Store
  LPS Large Polyp Stony coral or, Local Pet Store
  LR Live Rock
MH Metal Halide lighting
MO Mail Order
  Nano Reef A very small reef tank. Many times they can be less than 15 gallons
  NH3 Ammonia
NO Normal Output fluorescent lights
  NO2 Nitrite
  NO3 Nitrate
NSW Natural Salt Water
  ORP Oxygen Reduction Potential
Overflow A device that takes water from the tank and sends it to the sump
PC Power Compact lights
  pH The Base/Acid reading for a fish tank. 7.0 is neutral, above 7.0 is basic (alkaline), below 7.0 is acidic.
pods Amphipods, copepods, etc. - small crustaceans crucial to keeping a reef tank. Typically hitchhikers on live rock.
  PVC PolyVinylChloride - plumbing pipes typically used in households and for plumbing reef tanks
RO Reverse Osmosis - a type of tap water purification
RO/DI Reverse Osmosis/DeIonize - a type of tap water purification
SD SouthDown Tropical Playsand
  SG Specific Gravity - Basically, the amount of salts dissolved in the water.
Shroom Mushroom Anemone
  SPS Small Polyp Stony coral (such as Acropora)
Sump A secondary tank, usually underneath the display tank for keeping filtration and heating gear.
  SW Salt Water
  T5 T5 Florescent Lighting
  T5HO High Output T5 Florescent Lighting
Turbos Turbo Snails - A large algae eating snail
TWP Tap Water Purifier
  VHO Very High Output fluorescent lights
  Zoo/Zoe Zooxanthellae - a photosynthetic film covering many corals. Provides food and color typically.