[Motor31]

It is supposed to be filtering the water from both sources per the folks at the factory. It depends on who routed the water lines when your coach was built. In our case it seems to be filtered in both cases. It is not filtered going into the tank, that's just a gravity feed hose to fill it. If you use one of those inline hose filters then you are getting filtered water into the tank. I used to use one of those all the time but they are double the cost of the house filters and don't last as long in our experience so we stopped using them. If we go someplace where the water is really nasty (like Indiana) we'll use a hose filter to start with.

The only real heartburn I have with the shurflo filter is the inability to find "O" rings for it. I had to call the manufacturer and they sent me a couple. I treat them very gently to make them last.