You need to get an analysis of your water and provide the results in order to get informed advice about treating your water. There are some places that will do a basic analysis with out charge--Sears is one. You could also check with the local health department for a recommendation as to where you can get your water tested. The other souce is to look in the yellow pages. At a minimum you should have a test for hardness, pH, iron, total dissolved solids (TDS), and manganese
Much of Indiana has very hard water because of the limestone that underlies the state. If in fact you have hard water, as suggested by the fact that the last tenent installing a softener, the coppery residue is unlikely to be due to the copper pipes going bad.