και ένα extended version.....

AB=Aqualine Buschke, lighting manufacturer
AC=Activated carbon, chemical filtration
media /alternating current
AC II=AquaController II, all-in-one monitor & controller
acro=Acropora, a type of SPS coral
AFAIK=As far as I know
AFM=Aquarium Fish Monthly, magazine
AGA=All-Glass Aquarium, aquarium manufacturer
AL=Aqualink, aquarium bulletin board
ALK=Alkalinity, measure of buffering capacity of water
AM3K=Ampmaster 3000, a model of water pump made by Dolphin Aquarium & Pet Products, Inc.
ARS=Aquatic Reef Systems, RO/DI mail order place
ASAP=As soon as possible
ATC=Automatic temperature compensating, a feature on some refractometers
ATM=At the moment
ATS=Algae turf scrubber, reef setup technique
Bfly=Butterflyfish
BOD=Biological oxygen demand/Board of Directors
BTA=Type of anemone (Entacmaea quadricolor) / bubble-tipped, bulb tentacle, bulb tip
BTW=By the way
Ca=Calcium
CA=Custom Aquatic, mail order place
CaCl2=Calcium chloride
CaCO3=Calcium carbonate
Ca(OH)2=Calcium hydroxide
CC=Crushed coral / Counter current, type of protein skimmer
Cl=Chlorine
CO2=Carbon dioxide
CO3=Carbonate
CPR=Creative Plastics Research, manufacturer of fresh and salthingyer products
CSL=Custom Sea Life, lighting manufacturer
CTA=Cellulose triacetate, type of RO membrane
Cu=Copper
CYANO=Cyanobacteria
DD=Downdraft, type of protein skimmer
DE=Double ended metal halide metal bulb
DFS=Drs. Foster & Smith, Inc., mail order place
DI=Deionization, type of water purification
DIY=Do it yourself
dKH=Degrees of carbonate hardness, measure of alkalinity
DO=Dissolve oxygen
DOC=Dissolved organic carbon
DSB=Deep sand bed
DT's=Brand of refrigerated living phytoplankton
ER=Euro-Reef, skimmer manufacturer
FAMA=Freshwater and Marine Aquarium magazine
FAQ=Frequently asked questions
Fe=Iron
FFE=Flying Fish Express, mail order place
FO=Fish only, type of marine aquarium
FOWLR=Fish Only with Live Rock
frag(s)=Broken or cut pieces of coral which will eventually grow into a new animal
fuge=Short for refugium
FW=Freshwater
FWIW=For what its worth
FYI=For your information
FYM=For your misinformation
GAC=Granular activated carbon, chemical filtration media
GAL=Gallon
GBR=Great Barrier Reef
GFCI/GFI=Ground fault circuit interrupter / Ground fault interrupter
GOB=Green open brain
GPH=Gallons per hour
GSP=Green star polyps
H2O= Water/ H2Ocean
HCO3=Hydrogen carbonate
HD=Home Depot
HID=High intensity discharge, type of light
HO=High output fluorescent light
HOT=Hang on top, type of skimmer
HPS=High pressure sodium, type of light NOT for reefs but the ballasts concern them
HQI=High quartz iodide, type of light
HSA=High speed aeration, type of proteins skimmer
HTH=Hope this helps
I=Iodide
I2=Iodine
IA=Inland Aquatics, mail order company
ID=Identify/Identity
IIRC=If I recall correctly
IM=In my
IMCO=In my considered opinion
IME=In my experience
IMEO=In my expert opinion
IMHO=In my humble/honest opinion
IMNSHO=In my not so humble/honest opinion
IMO=In my opinion
IO=Instant Ocean, brand of synthetic salt mix
IO3=Iodate
IOW=In other words
IPSF=Indo-Pacific Sea Farms, mail order place
IR=Infrared, type of light of longer wavelength than visible light
IRC=Internet relay chat
ISP=Internet service provider
JME=Just my experience.
JMO=Just my opinion.
K=kelvin (mechanism for measuring spectrum of lighting, should be labeled degrees K) / Potassium
KALK=Kalkwasser, German for calcium hydroxide solution or limewater
KI=Potassium iodide
KISS=Keep it simple stupid
L=Liter
LED=Light emiting diode
LFS=Local fish store
LHS=Local hardware store
LMAO=Laughing my *** off
LOL=Laughing out loud
LPS=Large polyped Scleractinian (stoney) coral
LR=Live rock
LS=Live sand
LT=Litre
LTA=Type of anemone (Macrodactyla doreensis) / Long tentacle anemone
MACNA=Marine Aquaria Conference of North America, held annually
MD=Marine Depot, mail order place
MEQ/L=Milli-equivalents per litre, measure of alkalinity
Mg/L=Milligrams per litre
Mg=Magnesium
MH=Metal halide light
MJ=Maxijet, powerhead manufacturer
MM=Miracle Mud, method of aquarium filtration
MO=Mail order
MV=Mercury vapor, type of light
Na=Sodium
NaCO3=Sodium carbonate
NaOH=Sodium hydroxide
NFW=No way
NH3=Ammonia
NH4=Ammonium
NNR=Natural nitrate reduction, reef setup technique
NO=Normal output fluorescent light
NO2=Nitrite
NO3=Nitrate
NP=No problem
NRN=No reply necessary
NSA=North Side Aquatics
NSW=Natural seawater
O2=Oxygen
OBTW=Oh by the way
ORP=Oxidation reduction potential, the ability to take or give electrons
OTOH=On the other hand
PA=Premium Aquatics, mail order place
PAR=Photosynthetically active radiation, lighting quantity
PC=Power compact fluorescent light
PFO=Lighting manufacturer
pH=Measure of the concentration of hydrogen ions, equal to -log[H+]
PH=Powerhead, water pump
PITA=Pain in the @ss
PLS=Please
PM=Precision Marine, marine filtration component manufacturer/ Private Message
PO4=Phosphate
pods=Non-specific types of copepods, amphipods and such
POS=Piece of doodoo
PPM=Parts per million, equivalent to mg/l (milligrams per litre)
PUR=Photosynthetically usuable radiation, lighting quantity
PVC=Poly vinyl chloride, used for piping / plumbing
RC=Reef Central, aquarium bulletin board supreme
RDO=Reefs.org ("reefs-dot-org"), aquarium bulletin board
RK=Reef Keeping, on-line aquarium magazine
RO/DI=Reverse osmosis, followed by deionization, type of water purification
RO=Reverse osmosis, type of water purification
ROB=Red open brain
ROFL=Rolling on the floor laughing
ROFLMAO/ROTFLMAO=Rolling on the floor laughing my *** off
ROFLOL=Rolling on the floor laughing out loud
ROTFL=Rolling on the floor laughing
ROTFLOL=Rolling on the floor laughing out loud
RR=Reef ready, aqaurium with pre-drilled holes and overflows/ Razorback Reef
RTN=Rapid tissue necrosis
RUGF=Reverse flow undergravel filter
Saki=Iwasaki, light manufacturer
SAL=Salinity
SCWD=Switching Current Water Director, type of wave machine
SD=Southdown, type of sand
SE=Single ended, lighting designation
SG=Specific gravity
SHO=Super high output fluorescent light, equivalent to power compact fluorescent
Si=Silicon
SiO2=Silicon dioxide
SITD=Still in the dark
SO=Significant other
SPS=Small polyped Scleractinian (stoney) coral
Sr=Strontium
SW=salthingyer / seawater
TAR=Type of magnetic ballast / substance used to embed magnetic ballast coils
TBS=Tampa Bay salthingyer, mail order company
TFC=Thin film composite, type of RO membrane
TIA=Thanks in advance
TIC=Tongue in cheek
TM=Tropic Marin, manufacturer of fresh and salthingyer products
TRT=The Reef Tank, aquarium bulletin board
TTYL=Talk to you later
TWP=Tap Water Purifier from Aquatic Pharmaceuticals
UGF=Undergravel filter
UV=Ultra violet, type of light of shorter wavelength than visible light
VHO=Very high output fluorescent light
W=Watts
WD ( W/D )=Wet dry, method of aquarium filtration
WPG=Watts per gallon, lighting quantity
WTH=What the hell
WYSIWYG=What you see is what you get
X10=Automation/control products - Electronics mail order place
YMMV=Your mileage may vary