How to Bleach an RV Water Tank

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Recreational vehicle campers (RVs) typically have three holding tanks that allow you to live in the great outdoors. A gray water tank holds kitchen and bath waste water. A black water tank holds toilet waste. A third tank holds fresh drinking water.

Keeping your fresh water tank sanitized is critical to avoid unpleasant tastes, odors and gastrointestinal illnesses caused by bacteria buildup inside the tank. All RV owners must practice good hygiene by cleaning drinking water tanks and water lines with bleach at least once a year.

Items you will need

  • Fresh water source

  • Measuring cup

  • Household liquid chlorine bleach

  • Funnel

  • Drinking hose

  • Sewer system connection

Step 1

Turn your RV water heater off and wait a few minutes. Go to the outside compartment where the water heater is located, pull the drain plug (otherwise known as a "petcock") and open the pressure relief valve. This will help expedite water from the RV water system.

Step 2

Algae, slime and bacterial debris can build up in the hot and cold water lines. You'll need to start by emptying the lines. Start by finding the two low point water lines in your RV and open the valves to let the water out. Your owner's manual should tell you where they are located. You will also need to open the drain for the water tank and let all water run out. To help water drain faster, turn on the water pump, too, but once all water is out, turn it off to avoid burning out the pump. When you finish these tasks, close all drains.

Step 3

Disinfecting the RV's water lines and tank is easy with household bleach. For every 15 gallons of fresh water that your tank holds, put a fourth cup of liquid chlorine bleach into a bucket and mix with water. Use a funnel to carefully pour it into the tank. When it's all in, take a drinking water hose and continue filling the tank until it's almost full.

Step 4

Once you have filled your tank, go inside to turn on the water pump. Open every faucet until you smell bleach coming through the lines, then turn them off. Take the RV on a short drive if you can, to slosh water around in the tank. Let the solution sit in the system overnight.

Step 5

Drain the bleach water solution into a proper septic tank system, then refill the fresh water tank with potable drinking water. Finally, turn on the water pump again, open all faucets and run water until the bleach smell disappears.


  • Sanitizing your tank is critical for proper RV care, gastrointestinal health and clean water. Neglecting this important maintenance procedure can cause clogged water lines, microbial infestations and intestinal illnesses.


  • If you haven't performed this procedure before, you may want to repeat this procedure to ensure all bacteria and contaminants are cleaned from the system.