Clean Your Caravan Or Camper Trailer Water Tanks [Step By Step]

Dirty grubby foul tasting water in your caravan water tanks. Yes it’s horrible. How do you clean your caravan water tanks? I will explain how in easy to follow steps.

I have spent some time researching and testing and have come up with the following method to clean my caravan water tanks. It’s simple and it follows on from sound government safety guidelines*. Alrighty then, let’s get started!

  1. Drain tank water lines and taps
  2. Add a small amount of plain household bleach and refill your caravan water tanks
  3. Leave it to sit for a day
  4. Turn all of your caravan taps on and let them go until water runs clear. Drain your tanks
  5. Refill your tanks with clean water.
  6. Turn all of your caravan taps on and let them run for a minute.

Read on below for detailed step by step instructions to clean your caravan or camper trailer tanks as outlined above. It’s easy to do and it’s very cost effective.

Clean Caravan Water

Clean Caravan Water

1. Drain Tank Water Lines And Taps

Before you add in any cleaning products it’s a good idea to empty the water out of your tanks and taps. Two reasons to do this are.

  1. If your caravan tank water is infected with nasties then it makes sense to be cleaning the tank and not the water.
  2. Start with fresh water. Refilling your caravan water tanks gives a better chance of the cleaning chemicals you will be adding being able to mix well.
But I Keep My Caravan Water Tanks empty?

Give your water tanks a rinse out first if you keep your tanks supposedly “empty”. Why do I say supposedly? Ever had a look at where the drain plug is on your tanks and at the baffles in the bottom of your tanks? There’s no way you’ll ever get them completely empty without removing them and standing them on their end or side for a few hours.

Plain Bleach

Plain Bleach

2. Add A Small Amount Of Plain Household Bleach And Refill Your Caravan Water Tanks

What Do I Use As A Sanitiser In My Caravan Water Tanks?

Bleach is what’s recommended by Govt authorities to disinfect water tanks. The VIC Health Dept recommends you use 12.5 millilitres (mL) of liquid bleach (4% available chlorine) for every 100 litres (L) of tank capacity.
Bleach is cheap and effective as a disinfectant. It kills off many common bacteria such as salmonella, staphylococcus, streptococcus and E. coli. You can buy liquid household bleach at a supermarket or hardware store. Check the product has at least four per cent (4%) available chlorine and has no additives such as fragrances or detergents

How Much Bleach Do I Add To My Caravan Water Tanks?

Use the following table to work out how much bleach to add to your caravan water tanks to clean and sanitise them.

Tank CapacityQty Of BleachTank CapacityQty Of Bleach
50 Litres06.25 ml300 Litres37.50 ml
100 Litres12.50 ml350 Litres43.75 ml
150 Litres18.75 ml400 Litres50.00 ml
200 Litres25.00 ml450 Litres56.25 ml
250 Litres31.25 ml500 Litres62.50 ml
Other Cleaning Products Will Do The Same Job However They Cost A Lot More

If you have 200 litres water tanks here is the cost to use bleach compared to commercially prepared solutions. Remember that bleach will do the same job and bleach is what the government agencies recommend.

  • Milton Antibacterial Solution about $2.75
  • Camec Tank Clean about $15.00
  • Household bleach about $0.10
Refill Your Caravan Water Tanks

Fill the tanks up as much as possible. This will make sure that the cleaning solution is in contact with as much of the tank surface as you can. This will slosh the cleaning product around and make sure it’s fully mixed in.

Bonus Tip
If you find it hard to pour bleach into your caravan’s water filler then pour it in to the end of your filler hose. The water will push it through plus it’ll likely give it a swirl around inside the tank as it goes in. Plus it’ll even give the inside of your hose a clean!

Caravan Water Tanks

Caravan Water Tanks

3. Leave It To Sit For A Day

The times vary depending on what you read. One site says 15 minutes, another says 6 hours. According to the Department of Health and Human Services Victoria you should wait at least 24 hours after treating the water before using it. This allows for microorganisms to be destroyed.

In any case I recommend being cautious. Go with the longer version if different sources say different things. All you’ll lose is a little time. Waiting longer is a better option than the disinfectant not doing its job and you still getting sick.

Bonus Tip
Take your caravan for a drive during this time. Even though the tanks should be completely full there will likely be air pockets. Going for a drive will slosh the cleaning solution around and get to those pockets. It will also give the caravan water tank cleaning solution a chance to mix together again.

4. Turn All Of Your Caravan Taps On And Let Them Go Until Water Runs Clear. Drain Your Tanks

After you have waited for 24 hours it’s time to drain the water and flush your caravan water tanks. Everything I read suggests that the tanks should now be completely disinfected and the water should be safe to drink. Personally I would use this opportunity to drain the tanks and use the drained water to water the plants. Unless you live near a drought affected area where water is scarce. By emptying the tanks, any debris or dead germs will be removed. It will also help get rid of any bleach or chlorine taste that may hang around. Depending on the availability of water you might prefer to flush it another time to totally remove the taste.

B.E-S.T Water Filter

B.E-S.T Water Filter

5. Refill Your Tanks With Clean Water

After cleaning the caravan tanks it’s time to refill them with fresh water. Use the 24 hours you are waiting for the bleach to do it’s job of disinfecting your caravan water tank to get an inline water filter. If you don’t already have one you really should. The one to get is a B.E.S.T Inline Water Filter (cheap on eBay). We find them to be the best inline water filter to use while filling your tanks.

When Filling Your Water Tanks Why Use An Inline Water Filter?

The Problem
As a traveler, you can expect some big changes if you are used to town water or tank water at home. Some places have over-chlorinated water and others have under-chlorinated water, leaving you vulnerable to bacterial contamination. You may have access to town supplies as well as water from other sources. For example the caravan park in Forbes is supplied by chlorinated town water but if you travel a few kilometers out of town to the free camping area it is supplied by untreated channel water. There are many towns in Australia that are forced to shut down their water supply due to contamination. Alternatively you can take water from a rainwater tank or a creek. It might even be as simple as a change in the taste of the water that can upset your stomach.

The Solution
What is the Solution? A high temperature is set in your hot water to kill off bacteria, including legionella. Too often, I have heard RVers say that they “heat the hotwater just enough to take a shower”. Unless you are sure there are no bacteria in your hotwater system, let it run until it shuts off. The same thing happens when you lay your water hose on the ground and it becomes heated by the sun. This is the worst thing that can happen to the “domestic-style” filters. They are not meant to handle hot water. They breed bacteria more quickly, and the cheaper ones break down faster. With the B.E.S.T., this problem will be eradicated. Hot Water Systems NOT the B.E.S.T. !

Bonus Tip
Now is probably a great time to check your caravan plumbing lines, taps and fitting for leaks and repair or replace as necessary.

6. Turn All Of Your Caravan Taps On And Let Them Run For A Minute

Finally you want to flush out any taste of bleach or chlorine from your water lines and taps. Turn your taps on and let them run for a minute to give the lines and taps a good flushing.

Myths As To How To Clean Your Caravan Water Tanks

There are LOTS of crazy ideas on social media for ways to clean your water tanks that are complicated or just don’t work. Some of them are even downright stupid. A few even border on being dangerous.

  • Red Cordial – how is that supposed to work?
  • Vinegar – if it was the best method then government agencies would recommend it. Leave the vinegar for your chips!
  • BiCarbonate Soda – I’m no scientist so it might work, but how are you meant to get a box of dry powder in to your water tanks?

Clean Your Caravan Or Camper Trailer Water Tanks As Part Of Your regular Maintenance Schedule

When it comes to owning a caravan or camper trailer it’s really important to regularly maintain your gear. Keeping a regular maintenance schedule and tracking the completion of tasks is the best way to keep your rig in tip top condition. Things like regularly checking the tyres, water pipes and drains for leaks and checking batteries and safety equipment like smoke detectors.

A regular schedule will help you catch things early and prevent any small issues before they have a chance to become big ones. A big one that needs to happen regularly is cleaning asnd sanitising your caravan or camper trailer water tank.

Benefits of Cleaning Your Tanks

Whether you are on the road full time or take your caravan, RV or camper trailer out occasionally it’s important to clean and sanitize your caravan water tanks. You drink this water and if it becomes contaminated in any way it could have an effect on your health. When we regularly clean the caravan, RV or camper trailer fresh water tank and water lines it helps keeps us healthy and prevents illnesses.

How Often Should You Clean Your Caravan Water Tanks?

  • When it comes to cleaning your caravan water tank you should do it at least every six months.
  • If you are full-time on the road a six-month schedule works fine.
  • If you are an occasional camper when using your RV for camping trips you might want to consider a more regular RV maintenance schedule like every 3 months. What happens in the tank is mould, mildew, and bacteria can build up and water that sits in the tank for long periods becomes stale.
  • As you use the water in the tank the water level lowers and the areas not in the water build up moisture making it a perfect breeding ground. When you empty and fill it up over and over the water quality eventually can become less drinkable or have a bad taste even if you are using a water filter.

How Much Time Does It Take to Clean Your Tanks?

Cleaning your caravan fresh water water tank is a bit of a process. Allow about 24 hours to sanitize everything properly. You have to let the solution sit in the tank long enough to actually kill any bacteria and clean it out. This process can be done in about five to eight hours if you are in a hurry but for best results you need to allocate 24 hours.


I’ll admit it. I’ve been tricked in to buying and using Milton’s and Tank Clean in the past. It is pretty easy and cheap to clean your caravan’s water tanks. In the end bleach is what water scientists recommend (and it’s the cheapest solution).

* I’m in no way a health professional so I recommend you do your own research before following my step by step instructions to clean your caravan or camper trailer water tanks.

6 Steps To Clean Caravan Water Tanks

6 Steps To Clean Caravan Water Tanks