The thought of dumping and cleaning gray water (sinks, shower) and
black water (toilet) tanks on an RV might sound unpleasant and complex
to first-timers, but these tasks - along with sanitizing your fresh
water tank - are actually pretty simple.
A good rule of thumb is to partially drain the gray tank first before traveling to
ensure there are no leaks around the sewer hose and elbow. Once you have
confirmed a tight seal, close the gray tank and open the black tank
completely. When it is finishing draining, empty the rest of the gray
tank to act as a de-facto rinse for the hose. The place you connect the
flush hose once the tanks are empty will be clearly marked on your rig.
Sanitizing the fresh water tank is important, particularly in rentals
and RVs that have been in storage for extended periods. Fill your fresh
water tank and add 1/2 cup of bleach for every 15 gallons of water.
Make certain you bypass the drinking water dispenser on your kitchen
sink and the water heater line to prevent bleach from getting in them.
Turn on every faucet, including the shower, until you smell bleach.
Drive your RV from one fill station to another. This will swish the
bleach water around in the system. After you drain the bleach water out
and refill with fresh water only, run the water until you can no longer
smell bleach. This step might have to be repeated if the bleach smell
remains when the refilled tank is approaching empty again.
