If your water is coming from a well and the water is rust colored, then the problem is probably iron. If the water color is black it could be either sulfur, which has a smell like rotten eggs or manganese. All of these can be treated with our NaonCeram Filter . A bigger problem is if the water has a very fine dirt content which may indicate the presence of colloidal clay. A good indication if you have a clay problem is if water in a glass stays cloudy after sitting for 60 minutes. If this is the case we will also install a pre-sediment filter to prolong the filter life