Common Terms and Abbreviations

[waterbear]

FC free chlorine

CC combined chlorine or combined chloramines

TC total chlorine

pH Potential Hydrogen (how acidic or alkaline a solution is)

TA total alkalinity (the measure of bicarbonate ions in the water)

CH Calcium Hardness

TH Total Hardness (calcium and magnesium--useless for balancing water but most test strips only test total hardness and not calcium hardness)

CYA or CA cyanuric acid which is used to stabilize chlorine but too much will limit the disinfection ability

Br bromine

BCDMH Bromo-chloro-5,5-dimethylhydantoin (bromine tablets), normally used in a floater

cal hypo calcium hypochlorite, an inorganic powdered chlorine source that adds 7 ppm CH for every 10 ppm of FC added and is net pH neutral on use (alkaline when added, acidic on sanitation)

trichlor  a slow dissolving organic chlorine source that adds 6 ppm CYA for every 10 ppm of FC added, It's extremely acidic (acidic when added, acidic on sanitation) and not normally recommended for hot tubs for this reason. It is normally used in a floater or feeder

Dichlor a fast dissolving organic chlorine source that adds 9 ppm of CYA for every 10 ppm of FC added.It is slightly acidic (acidic when added, acidic on sanitation)

Liquid Chlorine or Shock, plain unscented chlorine laundry bleach, sodium hypochlorite an  inorganic liquid chlorine source that is net pH neutral on use (alkaline when added, acidic on sanitation). It's main side effect is causing a slight increase in salt level (sodium chloride), which has no negative effect on water chemistry.