For the last 20 years, Zodiac has been using a patented technology associating polyamides and titanium, both of which are totally free from the effects of corrosion. Today over 120,000 appliances have been installed without any corrosion defects. When a salt water chlorination method is being used, it may be important to install a check valve between the heater outlet and the salt water chlorinator to prevent high concentrations of chlorinated water from back siphoning into the heater.