This question comes up many times. Sure you can purchase efficient systems on the market, but do you have the instruments to ensure the system is right for your particular water source. The recommended way is to have your water analysed by a laboratory and then built a system to deal with the specific impurities the laboratory found in your water. In addition, any system requires constant monitoring of your filters to ensure you change the filter in time, there is no exact method because it depends upon the quality of your water source. If you wait too long to maintain your system, your water might be more contaminated after the filter process because bacteria have already multiplied in your filters and instead of removing contaminates it adds a whole new bunch in.
Why go through this whole expense and stress if you can have Quality Water conveniently delivered to your doorstep? This way you have peace of mind and can be sure that your family has clean water.