One of the things I love most about my RV is having water everywhere we go. I find it really convenient most especially because I always travel with the kids.

We don’t always have to rely on campgrounds to hookup for fresh water. It’s very helpful how we can be off the grid for days and have everything we basically need.

So how long can you keep fresh water in RV tank?

If you intend to use water for drinking, it’s been suggested to not keep the water for more than two weeks, especially if the RV is not in use.

If you are relatively new to RVing, then you might have some questions about the RV’s water system. There were things about it that I didn’t know back then that I find very helpful now.

For instance, the RV water system works differently from the water system we have at home.

The RV has three water tanks, each having different purposes.

The fresh water tank stores water for drinking, cooking, and bathing. The grey water tank is used to store waste water from the sink and shower. And lastly, the black water tank which is used to hold waste water from the toilet.

Out of the three tanks, the fresh water tank requires the least amount of maintenance. Because of that, it’s easy to neglect and overlook its cleanliness.


Which leads us to the question how long can we keep fresh water in the RV tank before it turns bad?

Read on to know more about keeping the water in your RV fresh and safe to drink.

Can I Keep The Water Fresh Longer In The Holding Tank?

The fresh water tank holds water that will be used for all your  water needs inside the RV. Regardless if it’s for drinking or cooking or bathing, the water will all come from the same tank.

If you intend to use water for drinking, it’s been suggested to not keep the water for more than two weeks, especially if the RV is not in use.

However, if you are just going to use the water for bathing, cleaning, and washing utensils, then you may keep the water for a longer period. For water heating solutions, please check out this guide.

One thing you have to consider though is how clean the tank is when you started filling it with water.


If it hasn’t been sanitized beforehand, then the water may turn bad faster than usual.

Also, if the water tank is not sealed properly, the quality of the water may be affected. And if the weather is hot, bacteria is most likely to grow easily.

These are the factors that you need to think about when planning on your water usage.

For me, it’s safer to bring a separate container for your drinking water so you are sure it’s not contaminated. The rest of the water in the tank, you may use for other purposes.

What Do I Do If There Is Algae In MY RV Fresh Water Tank?

An obvious telltale that there’s algae in the tank is when you start to see green patches or when the water started tasting funny. 

But don’t wait for those signs because algae can live in the water even before you even notice.


You don’t have to worry though because getting rid of algae is easy. You can also do some additional steps to prevent it from growing again in your tanks.

The key here is disinfecting the tanks and you’ll be sure to be algae-free. Here’s how.

What you’ll need:

  • Long-handled brush or soft sponge
  • ¾ cup of bleach
  • 15 gallons of water
  • More water for flushing

What you need to do:

  1. Remove algae patches by using a long-handled brush or soft sponge. Do not use abrasive materials such as steel brushes to avoid scratching the tank’s interior.
  2. Dilute the bleach in the water. Pour it inside the tank.
  3. Leave for at least two hours before flushing out using the RV’s water lines such as kitchen faucets and showers.
  4. To remove the bleach, fill the tank with clean water and flush again. Repeat until the smell of bleach has disappeared.

To prevent algae from growing again, drain the water tanks completely after each trip. Repeat the above steps 2-4 before refilling the tanks.

You may also use a smaller amount of bleach since you’ve already sanitized the tanks before your trip. 

You may use ¼ cup of bleach for every 15 gallons of water instead of ¾ cups of bleach.

It’s as easy as that and you’re all set for your next trip.


Does Sanitizing My RV Water Tank Often Help?

Since we are talking about water here, then it’s very important to sanitize the tanks before and after each trip.

Remember that even a little bit of moisture is still enough for algae to grow. If you leave it like that for a long time,  your tank’s interior will be full of algae in no time.

Some people who use separate containers for drinking water don’t give this much thought. 

As for me, it’s not something I would encourage you to do because you will still be using the water for other important purposes such as washing utensils or bathing.

I find it just as important to sanitize every now and then. Some RVers say you should sanitize at least twice a year.

But it’s all up to you. You need to assess once in a while. If the water starts  tasting funny before your scheduled cleaning, then you may need to do it more than twice a year.


Bottomline is that you shouldn’t miss this step.

Can I Clean My RV Water Tank With Bleach?

Bleach is excellent in removing algae and moss. It contains sodium hypochlorite that can break down organisms that are difficult to remove.

Because of that, bleach is highly recommended in cleaning RV water tanks, hoses, and lines.

Wrap Up

Some skip sanitizing their fresh water tanks often just because they have a different source for drinking water. 

But no matter how you intend to use the water in your fresh water tank, you need to clean and sanitize your tank regularly.

The steps are easy and the materials needed easily come in handy. Do this twice a year at the very least and you’re all set.