Came across a four bay self serve with a friction automatic (an Istobal if it matters). This is the second owner. He says the previous owner claims his water bill was cut in half when he had a system installed to capture his RO reject water. Now I know the previous owner would notice a bill cut in half, so I don't think he is mistaken. But my question is how is this possible? I'm thinking the RO water used is maybe 10% of his total consumption. Any thoughts?