Ronco Plastics 78H - 21 Gallon End Dump RV Holding Tank (No Rails)

Twenty-one gallons is a between-size, and that is exactly why the 78H exists. The 20 gallon class below it is crowded and the 25 gallon class above it is crowded, but if your coach came with a 21 gallon waste tank, a near-miss means an inch of interference somewhere. Ronco molds only one other tank at this capacity, the 56H end-dump at 22 x 22 x 12 inches, so between the two of them the size is covered.

At about 34 pounds, the 78H blank carries noticeably more material than most tanks its size, and it is built for what holding service actually is: gray or black water, sitting in the tank between dump stations. This is a sanitation molding, not a potable one. Full, 21 gallons of waste at 8.34 pounds per gallon comes to about 175 pounds.

If the footprint turns out wrong, the neighboring 20 gallon shapes run from the skinny 43H at 81 x 11 x 7.75 to the wide flat 24H at 40.5 x 30 x 5. One Source Plastics is an authorized Ronco Plastics dealer.

Fittings

This holding tank ships with its outlet molded in, ready to plumb. Add the Ronco 3-inch uniseal (F3UNISEAL), a loose pipe-to-tank seal you press into the outlet yourself, with no threads or nuts.

Technical drawing: download the Ronco Plastics 78H dimensional drawing - print it to plan your install. The outlet is molded in. Add the Ronco 3-inch uniseal to connect it.