Sunday, October 14, 2012

Can Phosphate Filters Be Used In Place of a Calcite Neutralizer To Stop Copper Pipe Corrosion On Acid Well Water?

Dear sir,

I have a problem with acid water and pinhole leaks in my copper pipes.  I am on a well and my water has a pH of 6.0, which I am told is acidic.  At first I planned on installed a calcite neutralizer

to make the pH neutral (7.0 pH).
But then,  I was also told by a local plumber that I do not need to neutralize the pH, all I need to do is install a phosphate filter.  He says the phosphate filter will coat my pipes and make neutralizing the pH unnecessary.  Is this true?

Gaithersburg, Maryland

Hello George,

Low pH or acidic water can definitely cause copper corrosion and pinhole leaks to develop in copper pipes.   The best pH for copper piping systems is 7 to 8.  On the pH scale (which runs from 1 to 14, with 1 being acid and 14 being very alkaline) the best pH for copper pipes is a pH between 7 and 8.  A pH of 7.0 is considered neutral.  Less than 7 is considered acidic, so we want to raise the pH to 7 or greater, to prevent corrosion For fighting copper corrosion a pH of greater than 7 but less than 8.5 is best..   In most cases, this stops or dramatically slows down the copper pipe corrosion.

Phosphate can also be added to the water, which can coat the interior of the pipes, and stop corrosion by laying down a microscopic barrier of phosphate which serves to insulate the copper from the acidic water.   However, phosphate works by combining with calcium to form calcium phosphate. Many acidic waters are also low in calcium.  So by using the phosphate filter alone, it may or may not work well depending on the level of calcium in the water.  There are various forms of phosphate available including liquid and crystals in various formulations, but the typical home phosphate feeder uses crystals in the form of sodium hexametaphosphate.

Since your pH is acidic, we recommend neutralizing the pH with a calcite neutralizer first. This is much more effective than a phosphate filter without a calcite neutralizer.

In some cases, the copper pipes are already severely corroded by the time homeowners realize that the water is acidic, and causing the blue green stains they see in the bath tub and on fixtures and laundry.

In this case, a phosphate filter in combination with a calcite neutralizer will work to heal the copper pipes faster, than a neutralizer or phosphate filter alone.  So if your copper pipe corrosion has been occurring for more than a few months, you might consider using a neutralizer, followed by a phosphate feeder. 

Acid Neutralizer, Calcite 7000  1.5 Cubic Foot Size:                   

Price includes free pH test kit to be sure of correct operation and contains all necessary media to get up and running.  This is the appropriate filter for pH of 6 – 6.8, if lower than 6 we recommend a blend of Calcite with Magnesium Oxide (Corosex) to be included with the system.

Uses approximately 25 to 50 lbs of calcite media per year, easy to add right through the dome hole.

Dimensions: 10" diameter x 61" height   ¾" or 1” pipe connectors and Bypass valve is included.

Phosphate System Cartridge, Heavy duty housing:      

Systems come complete with Phosphate cartridge, Heavy duty plastic housing with 3/4” inlet/outlet, and mounting bracket.

Allows for high flow and minimal pressure loss as cartridge is a by-pass feeder, meaning that some water flows around the cartridge.

Cartridge contains food grade type phosphate crystals that slowly dissolve in water inhibiting scale build-up and coating the pipes with a protective film, especially at bends in the pipe, tee’s, etc.