A wall-mounted hemodialysis supply box and drain cabinet for use in continuous renal replacement therapy is provided that comprises a corrosion-resistant enclosure defining an interior space having a forwardly facing opening with a hinged door, at least one water-supply valve, at least one variable height bag holder, a bottom wall with a drain, and a plurality of inclined inside walls configured to channel waste water and treatment fluids into the drain. A sprayer hose attachment for use in washing down and cleaning the interior space is also disclosed.