Using a quality water source is crucial. Water containing high concentrations of bicarbonate, calcium, magnesium, and salts may create sediments in the long run. Adequate water treatment is recommended to reduce water hardness. For optimum performance, operate the NEX Clean units daily, preferably early in the morning, to take advantage of the dew on the panel surface which enables cleaning with less water. The optimal duration of operation of the NEX Clean units varies from 15 to 25 seconds, depending on the severity of the surrounding conditions and the amount of dirt build-up.