I live in the area that there is no public water utilities. So I have my own well. I just got a 400 gallons stainless steel water tank. I can set it up to fill it with rain water. I can also can pump water from the well to it. However, I want to use rain water as the primary source of water and the water from well as the secondary. How can I do that?
I know that I can automatically pump water from the well to the tank if the water level lower that a certain level. But if and only if the well water is the primary source.
I also have a entire house water filtration system.