On any salt system, the optimum chlorine production occurs between 3200 and 4000 parts per million of salt. Zodiac (the salt generator we offer) recommends a salt level of 4000 ppm so that the addition of salt is not as frequently required. Allowing the salt level to fall below 2800 ppm may reduce the life of the cell. 4000 ppm is barely detective, the taste threshold is 3500 ppm for most people. In comparison, a teardrop is about 7200 ppm and ocean water is about 36, 000 ppm.