Metal tanks lose the long game. Aluminum pits under wet foam, stainless crevice-corrodes at the welds, and one day the bilge smells like fresh water where fresh water should not be. The B195 is the polyethylene answer: a 20 gallon marine water tank rotomolded in one seamless piece, with nothing to corrode, no welds to fatigue, and FDA-compliant material fit for potable service from the first fill.
Because it replaces a tank that already has plumbing, the blank-shell approach works in your favor. Ronco ships this tank with no fittings molded in; instead you print the drawing below, mark where the old system's fill, vent, and pickup need to land, and the shop spin-welds or thread-installs each one to your marks. The on-page fitting planner does the same with a few clicks. The result drops into an existing installation instead of demanding new hose runs.
It ships at 79 lb and holds about 167 lb of water when full at 8.34 lb per gallon, so keep the original bearers if they are sound - they were engineered for exactly this load. Ronco has rotomolded marine tanks in Tustin, California since 1974; a healthy share of that work has always been replacing metal tanks that gave up.
If this footprint is not quite your footprint, the boat tank category holds the alternatives, and the Ronco Plastics hub shows everything else the shop molds. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B195 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.
