In reverse osmosis, the idea is to use the membrane to act like an extremely fine filter to create drinkable water from salty (or otherwise contaminated) water. The salty water is put on one side of the membrane and pressure is applied to stop, and then reverse, the osmotic process. It generally takes a lot of pressure and is fairly slow, but it works. Over time the calcium in the water will harden and clog the pores in the membrane. The WATERKING will reduce the rate of this hardening and greatly extend the life of the membrane.