The iSpring RCD100 countertop reverse osmosis system offers an innovative solution for dealing with waste water compared to traditional RO systems that drain it away immediately. With this advanced RO system, waste water is cycled back into the raw water tank and initially mixed with the raw water. As the waste water getting a higher concentration of contaminants, it is separated in the right-hand side cube and not filtered again to ensure the RO membrane is not exposed to water outside its working concentration range. The collected waste water can also be recycled for non-potable uses such as mopping the floor or watering plants.