1. Bacteria. Softeners remove hardness(calcium, lime, magnesium) through a process called ionic exchange. Ionic exchange, however, does nothing to kill bacteria. Whether it’s coliform, ferric iron or e. coli, your softener is simply not the type of equipment used to remove bacteria.
2. Toxic Metals. Arsenic, Barium, Cadmium… There are many toxic metals present in wells all over the world. Softeners will remove about 25% of ferrous iron from the water, but beyond that, they are not very effective when it comes to removing metals from the water.
3. Silk. Typically indicative of a failing or cracked well, silk is very fine dirt. It does not respond to the process of ionic exchange and really just muds up everything it goes through.
4. Nitrates. Out in the field, most positive nitrate usually indicate either a leaky septic system or fertilizer runoff. In either instance, it’s nothing you want to deal with. They can be easily removed with high-quality reverse osmosis systems. You could make it even purer with the addition of a UV light.
5. Manganese. Notorious for sludging up systems as bad or worse than silk, manganese can be a huge pain for home owners and water professionals alike. Not to be confused with magnesium, manganese often looks black or dark brown and feel both oily, or flakey to the touch.