Rain is made acidic when the rain drops dissolve carbon dioxide from the atmosphere on the way to the earth. When the rain water permeates the ground table, limestone normally brings the pH up over 7. In the absence of limestone (which causes hard water), the pH remains low.
What if I don't do anything to correct the pH?
The acidity of the water will dissolve copper or metal piping from the inside, causing pin hole leaks which can be expensive to repair. This may appear years after the piping system has been installed.
The other issue is that low pH will dissolve iron. A water softener or iron filter will not remove the iron since the acidity strips the iron off of the media bed that was intended to remove it.
Solutions?
Install a Calcite Filter if your pH is below 7 but above 5.5 and your water hardness is 10 grains or less.
If your water pH is below 5.5 and above 4.5 and your water hardness is 10 grains or less, then you can apply a media called Corosex.
If your pH is below 4.5 and or your water hardness is above 10 grains, then a chemical feed pump system feeding soda ash would be the solution.
