The letter D in a dream represents confrontation with sacrifice. Full awareness of a situation that demands that you give something up or put others first. The symbolism is based on the design of the letter D being a straight line that is facing a half circle.
drain line: A pipe line which is used to carry water from the water treatment system to a waste system. drinking water: A water treated or untreated which is intended for human use and consumption and considered to be free of harmful chemicals and disease-causing bacteria, cysts, viruses or other microorganisms.
In short, free chlorine is chlorine that is available and ready to help keep your pool water clean. Combined chlorine has been âused upâ and will no longer help with sanitizing your water. Total chlorine is the sum of both the free chlorine and the combined chlorine.