How to Sanitize an RV Fresh Water Tank

Could the water in your RV be making you sick? Did you know that you NEED to sanitize the freshwater system from time to time?  We’re going to walk you through how to sanitize the fresh water tank step-by-step!

Keeping the freshwater tank clean is important to stay healthy – we use our fresh water in the RV for many purposes. Daily tasks like making coffee, brushing teeth, filling water bottles, and more are all things that require the use of fresh water. Making sure your water is CLEAN and uncontaminated is SUPER important to staying healthy on the road.

Why Sanitize?

Because we all tend to fill our water from non-municipal sources (like a well for example), issues with contaminants can develop. Since water tanks are made from plastics and chances are you have your RV where the weather is warm, there is a chance of the water becoming contaminated with things like algae, mold, or bacteria. Sanitizing the fresh water tank from time to time is a “best practice” RV Maintenance item. The process of how to sanitize the fresh Water tank is pretty easy!

First things first, shut off the hot water heater valves

The chemical name for bleach is Sodium hypochlorite. As you know metal and salt = rust. To prevent rust, we want to keep the bleach OUT of our hot water heater. Many of the parts are made from metal and we don’t want anything in the system that could open up the potential for rust to develop later.

Make sure the fresh water tank is about ½ full. – Mix Bleach & Water.

The supplies you will need for this process are:

  • Bleach
  • 1/2 gallon or larger pitcher
  • Funnel 
  • Some extra water (since you will not have your water for 8-12 hours)  
  • Any extra filters if you have an inline water filter so you can change them – especially if you cannot shut off the water supply to them. 

To start, you will want to have your freshwater tank 1/2 full. Adjust as needed until your tank level shows 1/2.

Rv Water Sanitize

You will be using 1 cup of bleach for every 50 gallons of water. In our rig, we have an 86-gallon freshwater tank. So we use about 1 ¾ cups of bleach.

Todd Henson from the NRVTA (National RV Training Academy) recommends 1 cup per 50 gallons – so we are going to go with the recommendation from the pro! 

Mix bleach in a pitcher with water and pour into the city water fill on the side (not using the city water hook-up spot). Fill the fresh water tank level to full.

How to Sanitize the Fresh Water Tank – Run all the faucets in the to put the bleach/water mix in the water lines of the RV.

Some tips for this process are listed below. You want to make sure you give this bleach solution time to disinfect everything properly.

  • Let it sit for 8-12 hours
  • Sanitize on a travel day – the water can slosh around and then you can dump it on the other end of the trip
  • Sanitize the system overnight
  • Remember to have other water available for drinking, washing hands, etc. 
  • Flushing the toilet is ok! (Hey might even clean the toilet)!
RV Water Faucet

Flush the RV water lines and refill the fresh water tank

Run all the faucets again and fill the freshwater tank. You want to keep running water through the lines until you no longer smell any bleach.

Don’t forget to set the hot water heater valves back to open for everyday use!

You’re all set and sanitized with a clean freshwater tank ready for your next camping trip! Speaking of that next trip out, you can download our FREE trip planning template.

Leave us a comment and let us know if you’ve ever sanitized your tank or if this is a newer concept for you. We love hearing from you!

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3 Comments on “How to Sanitize an RV Fresh Water Tank”

  1. Using bleach is an inexpensive option as you only need to use one cup of bleach for every 40 gallons

  2. Using bleach to disinfect water tanks is not new to every RV, but how much bleach is needed to disinfect an RV water tank. We need to know the exact amount to kill pathogens and keep them at a safe level. In general, we will need one cup of bleach for every 50 gallons of water. Therefore, if your water tank has a capacity of 25 gallons, use ½ cup bleach. If your water tank can hold 12-13 gallons of water, use 1/4 cup.

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