The Ronco Plastics B408 is a tidy 25 gallon rectangle, 32 x 22 x 10 inches, one of the most versatile shapes in the B-series: shallow enough for underfloor bays, compact enough for lockers, big enough to matter. The dual-role molding covers both sides of a water system; potable fittings finish it as a food-grade fresh water tank, waste fittings finish it as a gray or black holding tank.
At 30 lb empty it is a one-person install, and the full load stays reasonable at about 208 lb figured at 8.34 lb per gallon.
Nothing is pre-drilled. Print the drawing below, mark where fill, vent, and outlet belong in your rig, and the factory installs each fitting per order, spin-welded or threaded to those positions; the fitting planner on this page collects sizes and styles. Ronco has worked this way in Tustin, California since 1974.
Compare RV water tanks, RV holding tanks, and boat tanks. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B408 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.
