Forty-seven gallons under a foot of height. The 33W spreads its capacity across a 40.5 x 25.25 inch footprint precisely 12 inches tall, which puts it in rare company: most tanks this size need the vertical room of a range slide-out, while this one lies flat in a basement bay or under a platform bed and simply outholds everything around it.
The Water / Waste Holding Tank series designation means the shell is dual-role. Fresh-water fittings turn it into a potable tank - FDA-compliant polyethylene, safe for drinking water. Waste fittings make it one of the larger gray or black holding tanks in the line, big enough that dump-station stops become a choice rather than a schedule.
Twenty-two pounds empty is easy; about 392 lb full is not (water at 8.34 lb per gallon), so treat mounting as a structural task - low, centered, through-bolted. Alternatives on either side of this capacity fill the RV water tanks category and RV holding tanks; the empty tank still ships parcel, and the freight estimator gives the number to your ZIP.
Molded in Tustin, California, Ronco's home since 1974. One Source Plastics is an authorized Ronco Plastics dealer.
Fittings
This tank has a molded shape (see the drawing), so it is sold as a blank tank with no fittings installed. Add the Ronco 3-inch uniseal (F3UNISEAL), a loose pipe-to-tank seal you install yourself, if you need a sealed pipe connection.
Technical drawing: download the Ronco Plastics 33W dimensional drawing - print it to plan your install. Sold blank, with no fittings installed.
