Cleaning and disinfecting drain and waste water is becoming a major issue. European and national governments are limiting the amount of residues (chemical and biological) that can flow into the open water. In order to meet current and future regulations, growers must clean their waste water. From and economic and environmental standpoint, drain water should be reused as much as possible before discharging it. Drain water can be reused as long as the nutrient levels in the water are still usable for the crop. As soon as the nutrient levels are too high (which occurs mostly with Na), the drain water needs to be discharged because the crop can no longer use it. The Hortizone installation cleans the drain and waste water of chemicals and biofilm, using ozon oxidation. The installation generates its own ozon. Therefore, it does not require any other products except for power and compressed air. The largest installation can clean up to 10m3 per hour, the smallest starts at 0,7m3 per hour. This installation can be used for both cleaning drain water for reuse and for cleaning waste water. The installation can be operated through the computer or smartphone. Installation does not require specialized personnel, it can be implemented directly. The Hortizone installation is also one of the first installations to be certified for cleaning dischargeable drain water.