How to Clean Caravan Water Tank Nifty Tips and Tricks

If you’re already plotting your next great adventure on the road, it’s important to consider hygiene and safety across all the different parts of your caravan, camper trailer or RV. On top of your checklist should be: Your water system, or when, where and how to clean caravan water tanks effectively, avoiding water contamination, and making sure you have a great water supply with you.

Why Clean Your Caravan Water Tank?

Caravan interior

Camping is a big adventure, especially with a caravan or a camper trailer that can carry a lot of water via water tanks or simply through jerry cans.

Those who are pretty new to the lifestyle are often caught by surprise by how many caravan water containers can be added to an RV, ranging from tanks for carrying fresh water to tanks for carrying waste water or grey water until it can be safely disposed of. 

Parked RV at national park

Yes, you could literally carry litres upon litres of water with you on the road. There’s a rich lineup of RV water tanks, along with water tank accessories that are highly functional and enhance your access to water when you need it.

At the end of the day, the goal is to travel extensively (and with so much fun) without losing access to fresh, clean water again via a reliable water system. 

The reality is organic material such as harmful bacteria, biofilm, fungi and viruses build in these water tanks, which can harm your health as well as cause issues in the flow rate as well as longevity of your system. Since caravans are often not used for extended periods of time, it makes it more important to protect your drinking water and water for cooking while travelling. 

When It’s Time to Clean Up Your Water Tanks in the Caravan

Caravan on the go

We’ll hazard a guess: The last thing you would want on your camping trip is a relentless taste or smell in your water. This is already a giveaway sign that your water tank needs some TLC -- before any unpleasant surprise or disease during your getaway with family or friends.

Clean drinking water

Another telltale sign that it’s time to clean your caravan water tank: Your water already tastes or smells like plastic or some other synthetic material. 

Before we proceed with our tips for effective water tank cleanup, here’s one to remember: the first step to ensure the pristine quality of your water is to fill your water tank using a food-grade hose. Garden hoses are a common culprit behind tasty or smelly water cases. It should be fairly easy to pick up a good-quality food-grade water hose pipe at a camping shop near you.  

The 7-Step Process to Clean Water Tanks in Your RV, Caravan or Camper 

Follow this easy, simple seven-step process to keep your caravan water clean and spotless as drinking water. 

Empty the water out of the tanks and taps

Before you use any fresh water tank cleaning agent or similar products, it’s best to drain the water out of your tanks and taps. This serves two purposes:

  • It removes nasty stuff if the water is already contaminated in the first place
  • It evenly mixes the cleaning product and water together before the refill takes place 

Now, if you decide to leave your tank empty, it’s worth giving it a flush first. 

Add bleach, chlorine dioxide or a vinegar solution

Bleach solution

Given that it’s cheap and highly effective, bleach remains the “gold standard” when it comes to disinfecting RV water tanks. It kills off a wide range of bacteria, from staph to E.coli to salmonella, as well as your garden-variety flu and cold viruses. 

Also vying for attention is chlorine dioxide, considered another effective product for cleaning water tanks. It's said to be recommended by the World Health Organisation (WHO), rating it as the most powerful water sanitiser around. A well-known disinfectant used in more than 900 public water systems worldwide, it's also deemed safer than chlorine bleach, which can produce a number of byproducts such as carcinogenic trihalomethanes.

Perhaps the burning question in your head if you want to keep it natural: should I use white vinegar and baking soda to flush the water tank? The combination may not be as effective as bleach or a targeted cleaning product when it comes to sterilisation, but it’s a nice step for maintenance.

In a bucket, add a cup of baking soda to a few litres of fresh water. Pour it into the water tank, allowing the chemical reaction to occur once the white vinegar is added in. See it foam up and expand. 

Bonus tip: If you’re having trouble getting the tank cleaner or cleaning agent into the tank even with a tool, try to pour it into the hose then connect the hose to the tap. The water will do its job pushing it through, and you’ll eventually have a thorough mix. 

Refill the water tank

Fill the water tank up as much as you can, as this ensures that the cleaning solution is touching as much of the tank surface as possible. Doing so will also slosh the cleaner around to evenly mix it in.

Clean water from pipe

Turn on the taps

Do this until the water starts running. After all, who wants a clean water tank with nasty water still in the pipes? To solve this, turn on the taps until the water just begins running. Afterwards, turn them off. 

Wait at least 24 hours

After chlorinating, the health department recommends waiting at least 24 hours before using the water. This way, the microorganisms still present get destroyed. 

If you’re not too keen on this advice, it’s good to err on the side of caution and go for a longer period of time! Assume that the disinfectant is not completely doing its job and you can still get sick without enough time. You might have all the things in the world like a caravan water filter, but practising caution is still the best.

Next, flush the tanks and pipes

Once the 24 hours are over, dump the water and flush it out. By this time, the water tank should be disinfected adequately and the water is safe to consume. It’s still good advice to empty the tanks to get rid of any remaining debris or lingering taste of chlorine.

You might even want to flush it some more for an immaculate taste -- of course depending on the availability of water.

Drinking water from tap

Refill the tank with clean water

It’s safe to assume that your caravan tank is clean by now, and it’s safe to put fresh water back in. The 24-hour waiting time can also be a chance to filter the water.  

Bonus: Should You Leave Fresh Water in Your Caravan Tank?

Camping trailer in action

The short and simple answer is this: It doesn’t really do squat whether you do so or not. Various types of bacteria and fungi can still populate an empty water tank, whether full or partially filled with drinking water. 

It boils down to keeping your tank clean consistently before using them. 

You might ask: Will emptying the water tanks of potentially dirty water keep them clean? For starters, bacteria love moisture, if you empty your water tank then a potential bacterial growth will be avoided.

Wine glass and drinking water

However, you should beware water pooling on the bottom when you drain your caravan tank. There could still be a lot of moisture hovering in the air, too. 

So it makes sense to completely dry out and keep your tank clean, whether from dry and warm weather or leaving your caravan for a couple of days. 

How about if your tank is completely full? Bacteria are unlikely to grow inside the tank, as there’s no air for them to grow, and they need sunlight.  

No to Harmful Bacteria: How to Make Sure Your RV Water Tank Water Is Still Fresh

Bacteria and microorganisms

When trying to figure out how long water can sit in your RV fresh inside water tanks, there are various factors to consider. Think of how hot it is, if there are already germs introduced to the water tank, how much of them are there, and more. 

Since it’s difficult to determine the answers to this exactly, you can look at other things to keep your drinking water from the caravan tank fresh. Here are some of them:

  • Derive water from a decent source. 
  • When in doubt, use an inline water filter.
  • If you want to be sure about water quality, clean your water tank and water storage system. 
  • If your caravan’s been sitting out for a while, flush the water tank and refill it.  

Final Note on ‘Operation Clean the RV Tank’

Camping and outdoor caravan setup

How to clean your caravan water tank comes off as a cheap, easy and simple process of getting rid of harmful bacteria. Get the right tools, stock up on energy and patience and invest in the right water tank cleaner for your needs and preference. 

Camping at night

A lovely clean tank providing fresh water system-- if you're not keen on drinking bottled water during the journey -- goes a long way in keeping the peace and hygiene inside your caravan or motorhome while free camping, as well as extending the fun and excitement on the road. 


Through more EcoTraveller blogs, discover must-have caravan wash products to buy and the best portable toilet chemicals for your RV or motorhome!