The B341 is 9 gallons of genuine choose-your-own-adventure. Ronco lists it explicitly as water or waste, and the tank has no opinion until you order fittings: specify fresh water ports and it is an FDA-compliant potable molding for a day tank or a small galley supply; specify waste ports and the identical shell becomes a compact gray or black holding tank for a boat or van that just needs somewhere legal to put a few days of sink water. One blank, two careers.
At 15 lb empty it goes wherever you can reach - and because the fittings are installed to your marks, it plumbs cleanly even in the awkward spot you have in mind. Print the drawing below, place your ports with the fitting planner on this page, and Ronco spin-welds or thread-installs them in Tustin, California before shipping, the same made-to-order routine they have followed since 1974. One discipline to hold: once a tank has carried waste, it never goes back to fresh service. Decide the role before the first fill, not after.
Topped off, it holds about 75 lb of water, so give it a strap and a flat landing. The fresh-side alternatives live in RV water tanks and boat tanks; the dedicated waste shapes are under RV holding tanks; and the whole family is on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B341 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.
