maybe this can help with terminology on these boards
INTERNET/REEF SLANG
AC=Activated Carbon, or Alternating Current
AF=Aquarium Frontiers, an electronic magazine
AFK=Away from keyboard (also interpreted as A Free Kill in the game Quake)
AFAIK=As far as I know
AFM=Aquarium Fish Monthly, magazine
AISI=As I see it
ALK=Alkalinity, measure of buffering capacity of water
BOD=Biological oxygen demand
BRB=Be right back
BTW=By the way
Ca=Calcium
CaCl2=Calcium chloride
CaCO3=Calcium carbonate
Ca(OH)2=Calcium hydroxide
CC=Counter current
Cl=Chlorine
CO2=Carbon dioxide
CO3=Carbonate
CPU=Central Processing Unit (Computer)
CTA=Cellulose triacetate, type of RO membrane
Cu=Copper
CUL=See you later/catch you later
CUL8R=See you later
CYANO=Cyanobacteria
DC=Direct current
DD=Downdraft, type of protein skimmer
DI=Deionisation, type of water purification
DIY=Do it yourself
dKH=Degrees of carbonate hardness, measure of alkalinity
DO=Dissolved oxygen
DOC=Dissolved organic compound
DSB=Deep sand bed
FAMA=Freshwater and Marine Aquaria, magazine
Fe=Iron
FFE=Flying Fish Express, mail order company, United States
FO=Fish only, type of marine aquarium
FOWLR=Fish only with Live Rock, type of reef aquarium
FW=Freshwater
FWIW=For what its worth
FYI=For your information
FYM=For your misinformation
GAC=Granular Activated Carbon
GAL=Gallon
GBR=Great Barrier Reef
GMTA=Great minds think alike
GPH=Gallons per hour
HCO3=Hydrogen carbonate
HO=High output fluorescent light
HTH=Hope this helps
I=Iodide
I2=Iodine
ID=Identity
IE=Internet Explorer, WWW browser
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
IO3=Iodate
IOW=In other words
IR=Infrared, type of light with longer wavelength than visible light
IRC=Internet relay chat
ISP=Internet service provider
KALK=Kalkwasser, German for calcium hydroxide solution or limewater
KI=Potassium iodide
KISS=Keep it simple stupid
L8R=Later
LFS=Local fish store
LHS=Local hardware store
LOL=Laughing out loud, or Lots of Luck
LPH=Litres per hour
LPS=Large polyped Scleractinian (stoney) coral
LR=Live rock
LT=Litre
MACNA=Marine Aquaria Conference of North America, held annually
MASNA=Marine Aquarium Society of North America
MEQ/L=Milli-equivalents per litre, measure of alkalinity
Mg=Magnesium
MG/L=Milligrams per litre
MH=Metal halide, lighting
MO=Mail order
Na=Sodium
NaCO3=Sodium carbonate
NaOH=Sodium hydroxide
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
NS=Netscape, WWW browser
NSW=Natural seawater
O2=Oxygen
OBTW=Oh by the way
ORP=Oxidative redox potential
OTOH=On the other hand
PA=Premium Aquatics, mail order company, U.S.
PC=Power compact, high intensity fluorescent light
pH=Measure of the concentration of hydrogen ions, equal to -log[H+], (7 acidic, =7 neutral,)7 basic
PH=Powerhead, water circulator
PLS/PLZ=Please
PO4=Phosphate
PPM=Parts per million, equivalent to mg/l (milligrams per litre)
PVC=Poly vinyl chloride, used for piping/plumbing
RAMR=Usenet newsgroup rec.aquaria.marine.reefs
RO=Reverse osmosis, type of water purification
RO/DI=Reverse osmosis, followed by deionisation, type of water purification
ROFL=Rolling on the floor laughing
ROFLOL=Rolling on the floor laughing out loud
ROTFL=Rolling on the floor laughing
ROTFLMAO=Rolling on the floor laughing my *** off
RTN=Rapid tissue necrosis
RUGF=Reverse flow undergravel filter
SAL=Salinity
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=Saltwater/seawater
TAT=Thiel Aqua Tech, mail order company, United States
TBS=Tampa Bay Saltwater, mail order company, United States
TFC=Thin film composite, type of RO membrane
TFN=Thanks for nothing
TIA=Thanks in advance
TIC=Tongue in cheek
TTYL=Talk to you later
TY=Thank You
UGF=Under gravel filter
UV=Ultra violet, type of light, shorter wavelength than visible light
VBG=Very Big Grin
VHO=Very high output fluorescent light
W=Watts
WMC=Western Marine Conference, United States
WYSIWYG=What you see is what you get
YMMV=Your mileage may vary
YW=You're Welcome
YVW=You're very welcome
hthand good luck