We full time park host and currently don’t run a filter we trust the park water as needs to be tested on a regular basis. That said installing a filter is something I have considered in the past, but this has me thinking. We now have space behind our electric fireplace where our water inlet and pump are located. I might reconsider that or in our basement as even in cold temperatures it doesn’t get below about 45 degrees.
I will say we use standard water hose with foam pipe insulation and heat tape. The heat tape is about 18” longer than the hose, a couple inches for the water inlet elbow, and about 12” to wrap the Y connector at the spigot.