Ronco Plastics 24H - 20 Gallon Plastic RV Holding Tank (40.5" x 30.0" x 5.0")

Five inches. That is the whole height of the 24H, and it is the reason this tank exists. Underfloor bays, basement compartments, and the gap between chassis rails on a lot of coaches will not take a conventional holding tank, so Ronco molds this one as a wide flat pan: 40.5 x 30 inches of footprint spread so thin that 20 gallons of capacity hides where a toolbox would not fit. Full of gray water it carries about 167 pounds, spread across that whole pan, which is exactly how you want weight distributed under a floor.

The trade the pan shape makes is honest: you need the horizontal real estate, and you need drainage designed around a shallow sump. Ronco has been solving that since 1974 at their Tustin, California plant, and the drawing for this molding shows a drainage slope built into the pan so it actually empties instead of holding a permanent half inch of waste. Compare the deeper, smaller-footprint shapes like the 59H or the long narrow 44H at 80.75 x 14 inches if your space runs the other direction; the holding tank category sorts the whole family.

It ships as a 26 pound blank molding, and the fittings go where you say they go: spin-welded or threaded, located from the marks you make on the printed drawing. That is standard Ronco practice, not an upcharge or a custom order, it is simply how a tank maker that supplies coach builders works. OneSource Plastics is an authorized Ronco Plastics dealer.

Technical drawing: download the Ronco Plastics 24H 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.