How To Sanitize An RV Fresh Water Tank Without Bleach

Baking soda is the best alternative to using bleach to sanitize your RV fresh water tank. Baking soda does a great job at breaking down buildup in your water system and deodorizing so it gets rid of bad smelling water.

If you must use bleach then be sure to only use low concentrations of it and take the necessary precautions. Hydrogen peroxide also gets suggested a lot, but this will not properly sanitize so is best avoided.

Here is a detailed summary of the process for each of the 3 bleach alternative sanitizing methods, and some helpful RV tank maintenance tips.

how to sanitize an rv water tank without bleach

How Often Should I Sanitize My RV Water Tank?

After a very minimum, you should sanitize your RV water tank at least once per year. Generally, you want to sanitize the RV freshwater tank in the springtime, or whenever throughout the year you take your RV out of storage and want to use it.

Simply put, you want to sanitize the water system at the beginning of the season before you use it. Now, this is the absolute minimum recommendation, although many say that doing so twice per year is recommended.

These people say that you should do so once at the start of this season, and once halfway through the season. 

Of course, this does depend on how much water you use and how well you maintain the system. All of that said, if you notice that the water coming out of your faucet has an odd color, such as brown or yellow, or smells bad, then it is absolutely time to sanitize the RV’s water tank.

3 Best Ways To Sanitize An RV Water Tank Without Bleach

Although we will quickly touch on using bleach to sanitize your RV water tank, as well as hydrogen peroxide, today we want to talk about the ways to sanitize your RV water tank without using bleach.

Bleach is of course not the best for you or the environment, so many people want to avoid it.

1. Using Baking Soda

One good way to clean your RV freshwater tank is by using baking soda. Baking soda is a fantastic way to reduce the buildup in your RV water system.

Baking soda also does a great job at deodorizing, and therefore getting rid of odd smelling water. 

With that being said, baking soda is not as effective as the other solutions on our list today at killing bacteria and actually sanitizing the tank.

Now, baking soda will kill a good bit of bacteria and sanitize the tank to a certain degree, but maybe not 100%.

To sanitize your RV water tank using baking soda, follow the steps listed below.

  1. Mix 240 grams of baking soda with 3.8 liters of water.
  2. Use any source to fill up your freshwater tank, and then pour in this baking soda solution.
  3. Go for a 15 minute drive to really let the baking soda solution mix around in the tank.
  4. Open up all of the taps and faucets in your RV until no more water comes out. You don’t have to let this baking soda solution sit in the lines, such as with some of the other methods.
  5. Once again refill the freshwater tank using a municipal source.
  6. Open up all of the faucets in your RV and let them run for up to 10 minutes, or until the water comes out perfectly clear.

2. Using Vinegar

Another great way to sanitize the water system in your RV is by using vinegar, which contains acetic acid. This is a very effective alternative to bleach.

White distilled vinegar does a really good job at deodorizing your water tank, and it also helps reduce buildups. 

However, one of the biggest benefits that you get with vinegar is the fact that it is a disinfectant that has the ability to kill virtually all microbes and bacteria. This is of course what you are going for when you are sanitizing that water system. 

Furthermore, vinegar even has the ability to clear away calcium buildups, which can cause clogs and damage. V

inegar can be a bit smelly, so flushing out of the lines after using this method is important, or else you’re going to be showering in vinegar. 

Follow the steps listed below to sanitize your water tank with vinegar.

  1. Mix a solution with one part vinegar and one part water. You want to mix about 2.5 gallons of water with 2.5 gallons of vinegar. If you really want maximum sanitization effect, fill your freshwater tank halfway with fresh water, and then fill the other half with vinegar. Yes, you are probably going to need a lot of vinegar for this.
  2. You then want to go for a 15 or 20 minute drive, complete with many winding turns, as this will allow the vinegar solution to really work its way all throughout the tank.
  3. You now want to open up all of the windows in your RV, as it’s really going to smell when you turn the taps on. On that note, you now want to turn on all of the water fixtures in your RV, both in the kitchen and the bathroom.
  4. With the taps running, as soon as you smell the vinegar, turn the taps off. This is because you want the vinegar to sit in all of the water lines. You now want to let this vinegar and water solution sit in the water lines for at least four hours, so that it can kill all present bacteria. You may want to keep the windows open during this process.
  5. After about four hours, turn all of the taps on, and let the vinegar run out of the taps.
  6. You are now going to have to refill your freshwater tank with fresh water at least halfway, and then let that run through the system. Remember, you need to purge all of the vinegar from the system, or else you’re not going to have very pleasant tasting or smelling water.

3. Using Professional or Commercial RV Water Tank Cleaning Products

Perhaps the best solution is to use a professional or commercial RV water tank sanitization product. There are plenty of different options out there, so we do recommend doing some research. 

Moreover, we can’t really tell you exactly how these will work, as it does differ from one product to another.

However, it is safe to assume that the process is going to be very similar to using vinegar in the sense that you first have to pour it into the water tank, then get it into the lines, and then purge the lines of all remaining cleaning solution.

**A Note on Using Bleach** 

Of course, using bleach is always an option. Bleach does an absolutely fantastic job at killing any and all bacteria, germs, and microbes. It also helps to get rid of various buildups, and it’s a fantastic deodorizer as well.  

The fact of the matter is that bleach is generally the number one best way to clean an RV water tank. You just have to make sure that you use fairly low concentrations of it, and that you flush your water system out really well after using bleach.

You obviously don’t want to be consuming any bleach, as this is very hazardous to your health.

**A Note on Using Hydrogen Peroxide** 

Some people wonder whether or not it is possible to use hydrogen peroxide for this task. The simple reality is that wild hydrogen peroxide does have its benefits, but it won’t completely sanitize the water system for your RV.

Using hydrogen peroxide is best avoided.

Related: 7 homemade solutions to clean your holding tanks.

Is It Safe To Use Vinegar To Sanitize Your RV Water Tank?

Yes, vinegar is perfectly safe to use to sanitize your RV water tank. It is more than strong enough to kill any and all bacteria present, which is beneficial for you.

However, it’s not so strong that it will cause damage to the RV’s water system. 

On that note, even if you don’t flush out the system very well after using this method, even if you consume some vinegar, although it won’t taste nice, it won’t be poisonous. 

This is unlike bleach, where if you don’t flush the system properly, and you end up consuming bleach, there can be some serious health consequences.

RV Water Tank Maintenance Tips

Let’s go over a few additional tips on how to maintain your RV water tank to keep it clean and functioning properly.

1. Winterize The Water System

Something you always want to do to maintain your RV water tank is to winterize it. This means that you need to empty the lines, purge everything, and sanitize it all at once. 

This will help prevent bacteria, mold, and other such things from building up inside of the water tank when you go to store your RV. 

This is especially the case during the late summer months and early fall months when it is still warm enough for bacteria to thrive.

This also helps to prevent calcium and other buildups from occurring after a long year of adventuring.

2. Use Clean Water

Whenever you felt up your RV freshwater tank, you absolutely need to use a clean source of water, such as your own house water or municipal water.

You definitely don’t want to be using any kind of unfiltered water, especially from a source like a lake or a river. 

For one, you will pick up a lot of sediment, and other things such as calcium, which can then cause clogs to occur.

You can also pick up other things such as bacteria, microbes, and even insects. This absolutely has to be avoided if you expect to properly maintain your RV freshwater tank.

3. Empty The Tank At The End Of The Season

The other tip here is to always empty out the freshwater tank at the end of the season. You do not want to let old water sit in a tank all fall and winter. 

All of that water will contain bacteria and microbes that can multiply over time. This will make the sanitization process much harder at the beginning of the next RV season.

Related: How To Fix A Grey Tank That Won’t Drain.


As you can see, whether with bleach or not, sanitizing and RV freshwater tank is really not very difficult. Even better is if you properly maintain your RV’s freshwater tank, as this will allow you to sanitize it less often.

Madeline Cooper