The B103 does not know whether it is a water tank or a holding tank, and that is the point. This 20-gallon marine molding is one of Ronco's dual-role blanks: specify fresh-water fittings and it is a potable supply tank in FDA-compliant polyethylene; specify waste fittings and it is a gray or black holding tank for a weekender's head system. One mold, two boats' worth of jobs - the fittings you order settle it, and nothing comes pre-plumbed.
Twenty gallons is the honest middle of small-boat tankage: about 167 lb full at 8.34 lb per gallon, 26 lb empty. The blank's weight tells you the wall is thicker than the capacity strictly requires, which is Ronco's habit - tanks outlive the boats around them.
Fittings are installed per order at the Tustin, California plant where Ronco has rotomolded since 1974: print the drawing below, mark your locations for spin-weld or threaded fittings, or place them on the on-page fitting planner. Compare the rest of the marine lineup in boat tanks, or see everything Ronco molds on the Ronco Plastics hub. OneSource Plastics is an authorized Ronco Plastics dealer.
Technical drawing: download the Ronco Plastics B103 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.
