We are in the process of installing a new water heater in our cottage in Northern Mi. I think we could use a tankless heater, as there are weeks that we are not there. During other times we can have up to 8 people, when our family is there. My husband contacted our plumber at home & one up North & they both advised against the tankless heater. one indicated minerals from the well water. We do have a water softener, if that plays a part. Aren't there filters that you can use? I need some advise.