The B210 packs 50 gallons into a 33 x 27 x 14 inch block - a squat, broad-shouldered footprint that puts serious capacity under a berth or a dinette without demanding the long chase a low-profile tank needs. Ronco lists it for marine and RV duty, as fresh water or as waste, and means it: the blank shell becomes whichever tank your fitting order makes it, and it is never plumbed for you.
Run fresh, the FDA-compliant polyethylene is rated for potable service - 50 gallons is weekend-house capacity for a coach or genuine cruising range for a boat. Run as a holding tank, the same seamless rotomolded shell handles gray or black water without complaint. Either way, the arithmetic is identical: about 417 lb when full at 8.34 lb per gallon, sitting on a 33 x 27 inch footprint. Build bearers under all of it and strap to frame or stringer.
The tank ships at 42 lb - remarkably light for the volume - with no fittings installed. Print the drawing below and mark where the penetrations belong for the system you are building: fill, vent, and pickup for fresh; inlet, vent, and dump for waste. The Tustin, California shop spin-welds or thread-installs to your marks, as it has since 1974, and the on-page fitting planner takes the marks by click.
For hulls, start at the boat tank category; for coaches, the RV water tanks and RV holding tanks pages carry the visible range, and the Ronco Plastics hub carries everything. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B210 dimensional drawing - print it to plan your install and mark exactly where you want fittings located; Ronco installs spin-weld or threaded fittings to your marked spec.
