Whether you’re new to RV living or an old pro, you know that after connecting your sewer hose, you keep the black water tank closed, while you’re at an RV park. But many RVers are in the habit of leaving their grey water tank open anytime they’re hooked up at a campground. While this may prevent dirty water from backing up into your shower and sinks, it can cause some other truly unpleasant issues.

Here’s why:

  • If your grey water tank is allowed to fully empty, scum will build up in both the tank and the inside of the hose — in addition to being unsanitary, this can cause a really nasty smell!
  • If you let your grey water tank fill to ⅔ full before emptying it, a vortex is created which helps to remove the scum and eliminate most buildup.

grey water tank draining