Q. In the April 2000 issue of JLC (Letters), Rex Cauldwell recommended treating acidic water that eats copper pipe. Our water has a pH of 6.2 and definitely eats copper. What kind of water treatment equipment do I need?

A.Master plumber Rex Cauldwell responds: With a pH of 6.2, your water looks at copper and says yum, yum. You need an acid neutralizer, which passes the water through a container with neutralizing media. Look for an acid neutralizer with a capacity of at least 1 cubic foot of media. Acid neutralizers are available from many plumbing supply houses or from Sears. Plumbing supply houses can test your water and help spec the unit for you.

Acid neutralizers are either passive or active. A passive model, sometimes called an upflow, just sits there as water flows through it. Debris, iron, and other junk will collect in the media. In a passive model, the media tend to turn into a concrete-like mass after a while.

An active model backwashes itself to fluff up the bed and to get rid of the debris, which is flushed to a drain. The disadvantage of an active unit is that the backwash cycle consumes a couple of hundred gallons of water per week.

An acid neutralizer is installed in series with the incoming main water line and will require a 120-volt power supply.