How to Disinfect Fresh Water Tank in an RV

by Dusty Wilkens

Any RV or camper with a fresh water tank that has been sitting for some time should have its tank sanitized. Water in a storage tank can turn rancid while the RV is in storage, and ensuring that your friends and family have clean water for cooking and showering is part of normal maintenance for an RV owner.


Turn off your RV's water heater, and fill your fresh water tank full or nearly full to ensure that all parts of the tank are sanitized.


Fill the 1 gallon bucket almost full. Add 1/4 cup of chlorine bleach for each 15 gallons of water that your RV's fresh water tank holds. For example, a 45 gallon water tank requires 3/4 cup of bleach. Add this bleach mixture to your RV fresh water tank. Do not use scented or color safe bleach or bleach with any other additives. Use a new container of bleach, as bleach becomes less effective as a disinfectant over time. FEMA recommends "regular household liquid bleach that contains 5.25 to 6.0 percent sodium hypochlorite" for sanitizing water containers.


Run each faucet in the RV for 2 to 3 minutes, one at a time. This sanitizes each faucet and its water supply.


Add fresh water to the fresh water tank until full and let stand for at least 12 hours to allow the chlorine to kill any bacteria in the tank.


Drain the fresh water tank by running all faucets. Drain the water heater by opening the drain valve on it. If your RV has a drain valve on the fresh water tank, open it also.


Close all faucets, drain plugs and valves, and refill the fresh water tank with clean water from the hose.


Open all drain plugs and run all faucets to rinse any chlorine mixture away.


Close all drain plugs and valves and turn off faucets. Refill your fresh water tank again with fresh water. The water should be clean and safe at this point.


  • check Sodium Dichlor, used for sanitizing swimming pools may be substituted for bleach. Use 1 teaspoon of sodium dichlor. for water tanks up to 100 gallons in size.
  • check If the RV has been sitting an extended amount of time, it is helpful to drive or pull the RV some distance while the chlorine mixture is in the tank. The splashing water will dislodge any buildup inside the tank.


  • close If after rinsing the tank there is still a strong chlorine odor when running water in the RV, rinse the tank, faucets and water heater one more time to be safe.

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About the Author

Dusty Wilkens has been a writer since 2006, focusing on technical writing and documentation. He has worked in the IT field since 1997 with experience ranging from customer service and help desk duties to WAN and LAN design, security and implementation.

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