Pure Water Occasional
All Water Treatment Issue
Just for a change of pace, this issue of the Occasional will be only about water treatment. If you don’t find anything of interest, the next regular Occasional will be along soon. Here Pure Water Annie will trace the flow of water through a reverse osmosis unit, you’ll read a really slimy article about iron bacteria, you’ll hear about the nifty new Viqua VH420-F20 ultraviolet unit, learn the identify of the world’s greatest $77 water filter, find out what causes water to form scale and how to avoid it, hear the virtues of twin water softeners, and, as always, there is much, much more.
To read this issue online, go here.
The Pure Water Occasional is sponsored and produced by Pure Water Products and the Pure Water Gazette. Please write if there are questions.
Pure Water Gazette Technical Wizard Pure Water Annie Explains How Water Moves Through An Undersink Reverse Osmosis Unit
In modern home reverse osmosis units, tap water, driven by normal city water pressure, flows first through one or two prefilters which remove contaminants like sediment and chemicals, including chlorine and its by-products.
Next, the water enters the reverse osmosis membrane, a very tight, sheet-like filter, that allows water to pass but rejects dissolved solids like sodium and impurities like lead and arsenic. Some of the water entering the unit is used to cleanse the membrane surface. This water, called brine or concentrate, flows to the kitchen drain pipes.
The purified water leaving the membrane, which is called permeate, is stored in a small storage tank until it is needed. When the RO unit’s sink-mounted faucet is opened, the purified water, or permeate, is forced by air pressure inside the storage tank through another carbon filter, which gives it a final polish, and out the faucet.
This is a simplified description of a three-stage RO unit. Additional stages like sediment filters and additional carbon filters or specialty filters can be included. The simplified description omits a few very essential parts like drain flow control devices, the shutoff system, and check valves.
Iron Bacteria in Well Water
Well Management Program
Editor’s Note: This excellent description of the common well water problem known as iron bacteria is reprinted here from the website of the Minnesota Department of Health. I’ve added a couple of pictures. –Hardly Waite.
Does this describe your water……red stains in the sinks?….swampy, oily, or other unpleasant tastes or smells?….red, slimy growths in the toilet tank? If so, your well or water system may have iron bacteria. Iron bacteria are small living organisms which naturally occur in soil, shallow groundwater, and surface waters. These nuisance bacteria combine iron (or manganese) and oxygen to form deposits of “rust,” bacterial cells, and a slimy material that sticks the bacteria to well pipes, pumps, and plumbing fixtures. The bacteria are not known to cause disease, but can cause undesirable stains, tastes and odors; affect the amount of water the well will produce; and create conditions where other undesirable organisms may grow.