A vacuum cleaner conversion system utilizes a container or receptacle with an open top. A cover unit is configured to be positioned over the top of the receptacle and to be clamped to the receptacle to form a watertight connection. A first conduit extends through the cover unit. The conduit has an upper section extending above the cover and a lower section extending below the cover and into the receptacle. The lower section is totally enclosed at its lowermost end, but has an opening extending through its side surface. A second conduit extends through the cover. The second conduit has an upper section extending above the cover and a lower section extending below the cover and into the receptacle. The second conduit is open at its lowermost end. The first conduit has a connector providing an airtight connection between the conduit and a hose connected to a stand-up vacuum. The second conduit has a connector which establishes a watertight connection between the conduit and a hose extending to a dirt and debris collector nozzle unit. Once all elements of the conversion systems are in place, the vacuum cleaner is turned on. The suction provided by the vacuum cleaner extends through the first conduit and its opening, into the receptacle, and through the second conduit, its hose, and the nozzle unit, which allows the nozzle to suck up wet dirt and debris back through the wet hose, into the second conduit and then into the receptacle.