12v Water Pump

[Engineer Guy]

I've used the ~2.8 GPM Shurflo and it's 'plenty' of flow. I turn on the Shower Head with the integral Valve from Avion, and take a periodic Shower mentioned above. The Avion Valve is dynamic, so you can throttle down flow; not just shut it on/off. You could plumb in a similar Ball Valve for a lil extra moolah.

Neato lil Valves that have push button on/off capability can be added in-line to Shower Head Tubing. Another trick I've used is a Nylon Washer placed in the Shower Head Tubing fitting. The hole diameter sets the final flow, given the Pump, and Plumbing conductance. Drill out the hole to what works for you flow and usage-wise. An 'oversized' Pump can always be throttled down in flow by the tricks above. It will cycle on/off less, consuming less Water and fewer Amps. At one Well-driven House, our Flow Meter registered ~0.75 GPM when on continuously using a Water Pik Chromed Plastic Low Flow Shower Head at 30 [Well Pump 'on'] -> 50 [Well Pump 'off'] PSI.

Neato lil single-ended Accumulator Tanks are another trick. The Pump of choice pressurizes the internal Tank Bladder, which is where pressure is stored by pushing on a sealed air volume. This causes any given Pump to cycle on/off fewer times, extending life, although it runs 'longer' temporarily when on. They're small Well Pressure Tanks, which I've installed at 2 Houses. I saw a 2 Gallon Tank marked down to ~$35- at a Big Box Store. They're plumbed onto a 'tee' in the Cold Water Line, post-Pump.

Accumulator Tanks

Speaker/Lamp Wire or recycled Extension Cord Cable should run the Pump just fine, since the Amp draw is modest. Fuse/Breaker the Pump separately, of course, whether in or outside the Trailer. Due to their intentionally-forgiving Port design, Shurflo Pumps tolerate freezing IME.

There are also spring-loaded Valves that screw into the bottoms of Rainbird-style Sprinkler Heads. They close only when water pressure pushes them shut. They open, and drain down, in the absence of pressure. Very neat lil gizmos. No more blowing out Sprinklers in the Fall...