moved 2 crete wrote:The reverse osmosis system we have eliminates limescale in our kettle...
That's odd. I operated a large scale reverse osmosis filter in northern Greece to supply pure water to a humidity control system that had very fine spray jets, which could become rapidly blocked if fed with hard water. The inlet water had to pass through a permutit based water softener first or the the hard water would damage the reverse osmosis column. Thus it was the permutit water softener that was removing the chemicals that cause lime-scale not the reverse osmosis filter.
Also the membrane is flushed with water to remove the impurities that the reverse osmosis filter is trapping as long as water is flowing through the filter. That means that approximately the same amount of water that you consume goes down the drain roughly doubling consumption. In an area like Crete, which suffers quite severe water shortage, I would say that is probably acceptable if the filter is connected to a separate tap purely for drinking water, including for the kettle and boiling food, but not for a general kitchen tap.