Water Purifier

The demise of the Brita water filter jug was followed by a visit to Costco, wherein we saw one of those under-sink water purifiers with a reverse osmosis filter that feeds a small tap in the sink. For a very reasonable $150 this device features a particulate filter, two graded active charcoal filters, a storage tank and a "final filter". Since our sink had a hole for such a tap, plugged these thirty years, we figured that this was a good investment.
(I got a $129 air compressor complete with tank, valves, hose and car/bicycle adapter, so the going was fair.)

Here you see Meri helping me install the same. Below our sink is now a veritable nest of plumbing to service the insinkerator, the dishwasher, the two sinks, and a silver-based device that supposedly cleans up the plain cold tap water. Between the nest, my back, and Meri, the job was a tricky one.

Once done, we sat back and checked for leaks. The gizmo came with a snazzy tap that clamps over a water pipe and pierces it with a lance built into the tap, which I did not trust at first. It came with a similar device to access the drain. It needs this---an outlet for waste water---as it continuously flushes the reverse osmosis filter while filtering water. The thing is evidently not water-economical, but then it does not consume sodium chloride either---very American in its thinking. It has a lot of piping, all quarter-inch plastic, to interconnect all the parts. These are joined by a variety of plastic and brass fittings. Quite a rat's nest is the end condition of your cupboard.

Here you see the finished hardware. The big tank behind the flood light holds the reserve of pure water. The horizontal cylinder at the back is the silver-based (de-chlorinator?) for the main water tap. The small horizontal white cylinder above and behind the U-bend is the final filter (purpose unclear); the three blue cylinders are the mechanical and charcoal filters, and the horizontal cylinder above them is the reverse osmosis membrane's house. The black clamp on the small vertical length of drain pipe below the RHS sink drain is the outlet device. The inlet device is invisible behind that drain pipe, but you can see the green-coded pipe leading to it.
The frying pan collected the water that escaped from the first blue cylinder when I removed and refitted it to reseat the O-ring. Otherwise no problems. It took a few hours to fill the tank, which holds several gallons of water. During this time you could hear the trickle of waste water in the drain. Oh well, Kay likes her water pure, and that it surely is now!