What is the best water for Coffee?
Well, that a good question! After visiting with many coffee people, I have gathered the following as a basis for recommending the "perfect water" for coffee.

1. All oxidants removed. (Chlorine or other such sanitizers".)

2. All organics removed. (You know, dead fish, tadpoles, THM's,
    insecticides, pesticides, etc)

3. TDS (total dissolved solids) from 60 to 100 ppm
    (parts per million)

4. Hardness of about 3-4 grains per gallon. (51.3 to 68.4 ppm)

5. Low sodium water, ie, less than 10 mg/L.

6. pH depends on the Bean you are using, plus the method
    of extraction.

7. Iron, Manganese and copper gone, or less than 0.02 ppm.

What is the best way to get this type of water?
There is no single answer for this question, however, if we assume you are getting your water from a municipal supply, we *assume* the Iron and Manganese problems are taken care of by the city plant. (Some towns may not solve these problems -- you be the judge!) Copper *may* come from the supply itself, or, if the water is aggressive enough, it may actually be picked off the copper plumbing in your house as it sits overnight in the pipes. (Lead can also be leached out of the older "sweat" joints that may have used solder that contained lead.) It is best to "clear the pipes" the first thing in the morning before using any water for ingestion. Simply run enough water to clear your pipes of the 'overnight' standing water that *may* have picked up the harmful metals from your pipes -- use it to water your houseplants. If we use a good, properly sized carbon filter, we will substantially reduce the organics and oxidants in the water, as well as remove most of the particulates. However, we still have TDS and Hardness to worry about. If we soften the water, we do not reduce the TDS, we simply *exchange* the hardness minerals for Sodium -- which we don't want for coffee! The best answer (usually) is the reverse osmosis system. This *system* usually has a particulate and carbon filter (organics, oxidants and particulates are reduced); and a membrane (reduces the TDS by about 90% -- including hardness, sodium and others as well); all linked together in one flow path.

We can greatly improve the coffee by using any one of the above mentioned methods, but if we combine them, we get, for all practical purposes, the *best* water for your coffee! Rule of thumb: With an RO System, whatever impurities were in the water are typically reduced by 90% or more, leaving only water behind, which is what we really wanted, anyway!

How much sodium does Ion-Exchange add to my water?
For every grain of hardness in your water, 7.5 mg of Sodium will be *added* to each quart of water by the ion-exchange method. If you have water that is 10 grains per gallon hard; you will add 75.0 mg of Sodium per quart of water softened by ion-exchange. To put that in perspective, one 8-oz glass of milk contains 120 mg of Sodium, one slice of white bread contains 114 mg of Sodium. You must also remember that there is *probably* Sodium in the raw water, too. If your city supply treats your water by a "hardness reduction" treatment plant, you can be sure that the Sodium level in your water has increased as a result -- how much? Call your plant operator and ask -- it is information free to the public.