RVhometown is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn more

How to Sanitize Your RV Fresh Water Tank – A Detailed Guide

Writen by Dane Heldt

Fact checked by Robert Clark

how to sanitize your rv fresh water tank

As the owner of an RV, regularly maintaining your recreational vehicle is essential. It’s best to keep a maintenance routine, which includes checking the plumb, batteries in your alarms, tires, and fresh water tank.

Keeping up with your vehicle maintenance will help you catch things early and prevent significant problems on time.

On long journeys with your RV, you may have to rely on your RV’s fresh water system for days on end. That means it can become your only source of water during the trip.

Therefore, before any trip, you need to make sure you have enough clean water. One of the most important parts of preparation is keeping your RV’s freshwater system clean and disinfected.

Fortunately, it is easy to sanitize RV fresh water tanks! Here is a quick rundown of our tutorial on how to sanitize your RV fresh water tank.

So, without further ado, let’s get into the details!

Step by Step to Sanitize Your RV Fresh Water Tank


1. Things You Need to Prepare

You will need to prepare some basic supplies, which may already be in your home, including:

  • Chlorine bleach
  • 1-cup measuring cup
  • 1-gallon bucket or pitcher.
  • A funnel
  • Clean water source

2. Other Things to Note

You should also wear old clothes as there is a chance that you will get bleach or other solutions on you.

In most cases, this sanitizing process can take about half a day. So, we recommend starting in the morning. You can properly apply bleach during the day and complete the process before dark.

Since you will be working with bleach, choosing a well-ventilated location far away from plants is essential. You can flush the bleach solution without worrying about any mishaps.

3. The Step-By-Step Guide

  • Step 1: Turn Off Water Heater


Let’s start by turning off your rig’s water heater and allowing it to cool down. Otherwise, it may damage your water heater.

If your vehicle comes with an ice maker or water pump, you’ll need to turn them off. You must also remove an external water filter (if you have one). It will be terrible if the bleach solution travels through these parts.

  • Step 2: Drain Your Tank


If your RV fresh water tank still contains old water, you should empty it. In this case, you should keep your water pump on until the water in the tank is completely drained, then turn it off.

In addition, you will need to open the drain valve. Tighten it again when the water has run out.

  • Step 3: Sanitize Your RV Tank Using Bleach


It is always unwise to pour bleach directly into your freshwater tank. Instead, it is essential to dilute the bleach and create a bleach solution.

Besides, to determine how much bleach you’ll need for this project, you’ll need to determine the size of your fresh water tank.

On average, you will need one ounce of bleach for every eight gallons of water in your RV water tank or 1/4 cup of bleach for every 16 gallons of water.

So, to determine how many ounces of bleach you need, divide your total tank capacity by eight.

For instance, if your tank can hold 40 gallons of water, you will need 5 ounces of bleach.

After determining the amount of bleach you need, dilute your bleach in about a gallon of water before pouring it into the water in your RV freshwater tank.

Next, pour the bleach solution into the water tank through a clean funnel you prepared earlier.

Fill the tank with freshwater through a hose connected to a clean water source. You need to make sure that your entire tank is filled with water. That is the only way to effectively bleach RV water tank as it allows the bleach solution to contact every surface of your freshwater tank.

Ince the RV tank is full, you will need to turn on every faucet in your vehicle to distribute the detergent solution throughout your RV’s system. After turning them on for a few seconds, turn them off again.

  • Step 4: Take a Long Ride

We recommend leaving the bleach solution in your RV water tank for a while for maximum effectiveness; ideally, leave it for about 10 hours.

It’s boring to sit in one place and wait for 10 hours straight. So, it is not necessary to sit there the whole time. Instead, feel free to step away from your means and do something fun. Cleaning the RV fresh water tank overnight is also a good idea.

If you do not want to leave your recreational vehicle, it is okay to do a long ride. Thanks to that, the solution in your freshwater tank will be stirred up and the cleaning will be more thorough. But in this case, you will need to prepare a few bottles of freshwater water.

  • Step 5: Drain and Flush the Water System of Your Rig


Open all system water lines to drain the bleach solution from the RV tank. Once your RV fresh water tank is empty, fill your tank with fresh water and flush again to rinse the bleach thoroughly.

You may have to repeat the fill-and-flush process several times to remove the bleach and only stop until there is no more bleach smell.

  • Step 6: Final Step

Once your entire system has been flushed, turn on the water heater. If you use an external water filter, now is the perfect time to replace it. Remember to turn off the water supply before installation.

Last but not least, fill your RV fresh water tank according to the manufacturer’s instructions.

Alternatives to Utilizing Bleach

We recommend you to sanitize RV water tank with bleach as it is the most effective way to remove contaminants in the tank. However, many RVers do not want to add it to their drinking water or release it into the environment.

Various types of cleaners are available and can be used for this project. They will not be as effective as bleach but if this is your choice, it is alright to go with any RV fresh water tank cleaner below.

1. White Vinegar

White vinegar contains acids, which are great at neutralizing bacteria or other microorganisms. However, it only works well when heated to about 130°F or more. Otherwise, you will just make your RV fresh water tank smell worse.

2. Baking Soda

Baking soda will work great at making your RV’s freshwater tank look cleaner and won’t affect the smell and taste of your water. But it won’t do much to kill bacteria. Therefore, we do not highly recommend it.

3. Hydrogen Peroxide

Hydrogen peroxide is just as effective as white vinegar. But it also needs to be heated to 130°F for maximum effectiveness.



1. When to Sanitize an RV Fresh Water Tank

If you are wondering how often you should clean an RV freshwater tank, it depends on how you use your vehicle. It is best to clean your RV freshwater tank:

  • On a new rig before your first trip
  • After not being used for a while
  • After contamination (for example, being filled with water in Mexico)
  • Before extended periods of storage

2. Benefits of Sanitizing Your Tank

Whether you live in your RV full time or take your vehicle out intermittently, periodically cleaning your RV fresh water tank is essential.

The water in the tank can be contaminated and will affect your body when you drink it. By regularly cleaning the tank and water line, you will always have clean and healthy freshwater.

3. How Often You Should Sanitize

Mildew, mold, and bacteria can build up and cause the water in the tank to go stale over time. So, ideally, sanitize your RV fresh water tank every six months.

If you live in your recreational vehicle full-time, a six-month schedule is great. If you use your RV intermittently, you can shorten the schedule to every 3 months.

4. How Long Does It Take To Sanitize Your Tank?

You cannot expect to complete this process quickly. It usually takes about 12 hours to clean everything properly in most cases.

You must leave the bleach solution in your RV tank long enough to completely remove the bacteria. This process can be done in about 5 hours, but we recommend leaving it for 10 hours for the best results.

Take Away

By now, you should know how to sanitize your RV fresh water tank properly. Just by following the 6 easy steps above, you can be the proud owner of a disinfected RV freshwater system.

So, let’s enjoy your next camping trip with safe drinking water!

5/5 - (3 votes)