Chemically speaking, dichlor is the cyanuric acid molecule with two chlorine atoms and one sodium atom. This combination is a stable chlorine, which comes as a colorless solid. The cyanuric acid extends the life of the chlorine by shielding it from ultraviolet rays.
Dichlor granules dissolve quickly in water. They can be added to the waters surface, pre-dissolved in a bucket of water or added via a chlorination system. The pH level of dichlor is very stable, which means there is no need to add pH-neutralizing chemicals.
Unfortunately, cyanuric acid can build up in the pool water, reducing the effectiveness of the chlorine. To counter this effect, drain and refill some of the pool water. This dilutes the cyanuric acid and brings the water back in balance, upping the chlorines purification properties.
Dichlor should be stored in a covered container in a dry, cool area. Because it is granulated, it is easy to transport and lasts a long time. In addition, Dichlor has a long shelf-life. Dichlor is 80 percent available chlorine and will off-gas. This is a critical consideration when opening a container of dichlor. Safety precautions should be taken when handling and storing this chemical.