We camp a lot on the beach and I would have to go off the beach and fill up a 45 gallon bladder a lot and pump it into the trailer tank. I bought a standard RV pump hooked the bladder to the input of the pump pump and the output of the pump into the city water supply on the trailer with a hose. hooked up 12 Volts for the pump to the truck battery and use that as a city water connection I never had to pump water into the trailer. Still had the water in the tank is a standby. When the fawcets were open the pump would start up and pump water and when we shut off the fawcets the pressure would build up and shut the pump off just like the tank in the trailer.
2015 RAM 3500 SRW, 4X4, 3.73, 6.4 Hemi
2016 Eagle 338rets, Maxxis Tire Upgrade, Slide Toppers, Backup Camera, 2 - 15K AC units
Blue Ox Sway Pro Hitch, 2000 lb. Bars