Water filtration when boondocking

Yah, I hear ya.

Probably overkill here, but,

One thought is the Berkey Systems, pricey but a good filter, just put on sink...
One time expense, worth it to me but I'm full time.. so..
I also have two filters on the hose fill up to tank, just to get rid of any debris..

Are you planning on filling your water tank from streams, lakes, or other untreated sources?

I would avoid that if at all possible. In fact after years and years of RV travel and lots of boondocking, I have never had to do that.

We have had a Berkey for several years with 4 of the black filters. It isn't just a water filter but also a purifier, big difference! You won't need replacement filters for many years as you just occasionally scrub the filters clean, unlike most other short-lived systems. It is gravity filtered, but the water runs through fairly quickly.

We use it constantly for drinking and cooking at home and always take it camping with us. It sits on the counter and gets strapped in some cleats when traveling (water must be low otherwise it will slosh out on rough roads). It gets filled at the camper sink out of our FW tank. We have yet to use "pond" water, rain water, etc., but feel confident we could if we had to.

100% recommend this simple and effective system if you have a place to put it in the camper. Plus, if there is a zombie apocalypse, you know you can always have clean water. I think pricewise, it pays for itself quickly.

You already have a way to filter/purify water as fast as you need to for cooking and drinking?
On trips where you expect to need more than what your tank holds use that and other water source from start. Fill glass or coffee pot from the water you have filtered, instead of faucet.
And for water that is "used"; How dirty is it? Your dish water is clean enough to carry the cornbacked snake out of camper, so is what you can catch in a bucket between your feet while you shower. If you catch the water as you rinse dishes, add soap and boiling water next time you do dishes, can save a lot of water.

Siphon/gravity will NOT provide enough pressure for any good water filter. Use a pitcher water filter.

No need to give up your backpacking techniques.
A different approach would be to use one of the many water purification products such as Aquamira
No filter to clean/replace and no chemical taste (that we have ever detected anyway). Lightweight and doesn't take hardly any space.
Disadvantage of course is that it doesn't remove solids.....or change the color (muddy water is still muddy water.....)
However, Alum does a "pretty good job" of settling out most solids if you are willing to give it time (overnight) to work.
With the combination of the two (Alum and Aquamira), I wouldn't hesitate to fill my tank from almost any water source (unless there was heavy metals or chemicals involved). The water may not look pretty, but it will be safe to drink.

My water will always come from some kind of piped source. The reason I want to filter is to keep the fresh tank as free of contamination as possible. I know this is overkill, but better safe than sorry.

Two years of full time and many many months of part time and I have never wished I had filtered water for my fresh water tank. I do use a Brita or other final filter for drinking water.

If you do decide to use a filter, make sure it is a sediment filter that does not remove chlorine. Chlorine helps to avoid bacterial growth for pseudomonas and even more importantly serious pathogens such as Legionella. If you are not using the RV for a few weeks, sanitize the system.

I would never put untreated water in my rv tank..Having said that,I have multiple backpacking type water filters and bottles...Sawyer water filters and a SteriPen but not for the rv tank..I use them for gravity fed water into a jug to be used for coffee etc or drinking water..

I have four 50 gallon water barrels I take if needed for a long stay...

Sounds like a total pain in the ….. to filter however many gallons a Host Everest holds every time you fill up.
If one is intent on being protected from the evils of “non city” water, lol and not willing or able to buy bottled water for drinking ( the cooking one always cracks me up, as boiling water sterilizes it, which generally happens with any cooking scenario with water), then the economical and easy solution is filter/purify what comes out of the tap for drinking.
And if the water you’re pumping in smells/looks/tastes “bad” move on to another source or only add as much as you absolutely need for the terlet and bathing until you find a better source.
Haven’t camped in remote areas of the eastern and SE portions of the country, but never gave much thought to “water” in the western half of the country.
And if you do have a valid concern with the location and water, go somewhere else to get some water.
Also, same boat ballast bags and ballast pump make the ideal water storage/transport/transfer setup, IMo. Especially for large qtys. I’ve easily packed an extra 100gal on the back seat floor of the truck, with the kids in the back seat, to remote camping areas where we wanted to live the luxury life of having lots of water and the ease of not pulling water out of a river.