Maytronics recommends that the following water conditions as optimum for Dolphin robotic pool cleaners: Chlorine levels should be 4 PPM maximum and NaCl (Sodium Chloride) should be at most 5000 PPM.  The recommended water pH is 7.0-7.8 PPM And the ideal water temperature is 6-35°C / 43-95°F. Maytronics warns that temperatures below 15°C / 59°F may affect the climbing performance of the robot.