For every one gallon of filtered water you get, 3 to 5 gallons of water will pass out of the filters waste tube. That water is filtered through the first few stages and then moves through the RO
membrane. I use it for my FW
tank, others fill their washing machines, or water the lawn with it. It is good water, but higher in TDS
than your tap.
resin takes the water that is filtered through the RO
membrane and brings the TDS
to 0. Once it is depleted, it is cleaned out of the cannister and new resin is packed in.