Well Safe Sanitizer Pack is a simple all in one well shock kit designed for sanitizing private well supplies. It is recommended you sanitize a well twice a year, whether it is a new well or an existing well. If the well has been disrupted for service or repair, it is a must that it be sanitized. The well storage tank, pipelines, and fixtures should be rinsed with a strong sanitizing solution to kill all harmful pollutants. The Well Sanitizer Kit can be used for well, storage tank or cistern sanitation. The amount of tablets and granules used will depend on the amount of water in the system to be sanitized. Half of the total treatment will be completed with chlorine pellets and the other half will be completed with granular chlorine slurry. A 100-ppm chlorine concentration is ideal for sanitizing a well. To produce a 100-ppm chlorine concentration, use 2oz. sanitizer pellets or granules for each 100 gallons of water in the system. (2 oz. granules = 70 pellets) If the water has a high iron or sulfur content more chlorine may be needed to achieve 100 - ppm chlorine residual.