PH runs on a scale between 5.5 and 8.5. This scale represents acidic water and neutral water. 7.0 is neutral, so anywhere from 7.0-9.0 is actually really a good pH range. It’s alkaline and not corrosive to your plumbing in any shape or form.
On the other side of the scale, between 5.5 and 6.9, is acidic. The lower the number the more acidic the water is.
It is corrosive to anything that it touches, metal, that includes your copper plumbing, galvanized plumbing, faucets, hot water heaters as well any rubbers (which has a lot to do with your plumbing and fixtures).
So it’s very important to raise the pH up in your water if it is below 7.0.
So with that said, the best way to raise the pH balance of the water for the whole house is to use a pH neutralizer or also known as a calcite filter.
Calcite is a kind of marble that has calcium magnesium in it also known as calcite.
As you run water through the calcite filter to the home, it comes in contact with the calcite media and automatically dissolves into the acidic water until the pH goes to 7.0 to 7.1, which is neutral.
It regulates itself to stop dissolving at that point because it will only dissolve in acidic water and not alkaline water.
When that happens, generally, your water is naturally soft and that’s why it has low pH to begin with.
Typically, anywhere from 1 to 5 grains per gallon of hard water, it has a lower pH balance because there are not enough minerals in the water naturally to sustain a neutral ph.
When you run through the calcite filter to raise the pH, you're also adding calcite (a mineral) to the water.
So you’re gonna raise the hardness of your water. In a lot of cases, you go from having soft acidic corrosive water to having pH-neutral water (that is not corrosive anymore).
But now instead of soft water you have somewhat hard water. It’s kind of the nature of the beast with these systems. Very typical.
pH neutralizers have been around for over 50 years so it’s not new technology but it works very very well.
So in most cases, we recommend that you install a water softener after your calcite filter to remove the minerals so you have a pH-balanced water as well as soft water going to the home.
Article credit : Quality Water Treatment