If you are flushing your RV black and grey water tanks or cleaning out a tote tank, then you need to use a separate hose so that you don't risk cross-contamination with a drinking water hose. The Camco RhinoFLEX 25-Foot Grey Water Hose has a 5/8" internal diameter, is made of durable PVC and is bright orange so that you don't mix it up with your drinking water hoses by accident. The ends are compatible with standard garden hose threads. | CAMCO RhinoFLEX Clean Out Grey/Black Water Hose | Size 25'