The ankh is an ancient Egyptian symbol. It looks rather like a key. The ankh symbol was used in hieroglyphics and in designs. One of the artifacts carefully placed in King Tut's tomb was an ankh. The ankh must have meant something important to the ancient Egyptians, but we're not sure quite what that was.
You may want to look at my article HERE on lowering stabilizer. Basically if you use chlorine tablets, they have stabilizer in them and over time, can over stabilize the pool water and will need to be diluted. Also calcium levels that are high, rainfall can be a benefit to diluting the water as well.
Chlorine Chemistry. Chlorine is the predominant method of disinfecting water and wastewater and has been used for almost 100 years in the United States. Chlorine can be added to water as chlorine gas, an aqueous sodium hypochlorite solution, or solid calcium hypochlorite. When chlorine is added to water in any of these forms, it creates hypochlorous acid.