Water Filtration System

Under the sink RO systems aren't toys as previously suggested. They work and quite well in a home, under the sink, drinking water scenario. In an RV application they may not be practical. For starters they produce waste water. Depending on the quality of the unit it can be a higher than practical ratio of waste waster to drinking water. This can be recycled however but you would have to have a gravity capture and reintroduce into the system. Some RO systems use a powered pump to recycle waste waster but the energy consumption compared to the water saved is usually a wash - pardon the pun. The other challenge is pressure as you mentioned. Yet another issue is volume of water produced. Most drinking water systems are limited to about 3-6 gals over a few hours. Not practical for filling a water tank - but why would you? You really only need RO level filtered water for consumption. If just for a quick cleanup and washing dishes it's overkill. The other issue I can think of is power. An RO is going to need constant pressure to continue to produce water. That will require a water pump to run almost constantly. For that matter, any filtration system is going to require power, not just RO.

FWIW, I have installed RO systems in homes professionally for a few years. I am still working out installing a small RO system for drinking water in our RV. We don't really boondock however and I plan to incorporate cutoff switches so the pump doesn't constantly run and gravity waste water capture. Turn on as needed basically and use the waste water to clean bikes and outside stuff. My approach is really only to avoid carrying lots of bottled water which is so wasteful and has a large eco impact.

I applaud your efforts, it's an undertaking for sure.