How Much Bleach to Sanitize RV Water Tank?


Making sure that your RV has clean and safe drinking water all the time is crucial to your health and the people who are with you each time you are on an adventure. That said, it is really crucial for you to sanitize the fresh water system of your RV. It is also important for you to give it proper care and maintenance.

The problem is if you haven’t used your RV for a while or if it has been in the storage for a long time already, then the tanks for fresh water and hot water, as well as the water lines might be breeding grounds for bacteria. There is a great risk for harmful bacteria to grow and multiply in those areas.

You actually have a higher chance of preventing such a problem if you make it a habit to sanitize the water system and tanks.

The Best Time to Sanitize the Water Tank of your RV


There are actually many signs that will help you determine the perfect time for you to sanitize the water tank of your vehicle. For instance, if you already notice that there is a stale odor coming out each time you use the water from the system.

Note that this problem often happens if you leave water in the tank for quite a long time. In that case, sanitizing the whole water system and the tank is a must. Another indication that it is time to sanitize is if you let your RV sit for more than a month without using the water system.

You also need to sanitize in case you filled up the tank then suddenly received a boil water advisory. Another sign that sanitization of your water tank is a must if you encounter problems with slime or algae in the tank.

Also, remind yourself that while filters are capable of removing contaminants, like rust and sand while also improving the odor and taste of water, they are still not purifiers, making them incapable of killing bacteria and other harmful microorganisms. With that in mind, sanitizing the whole RV water tank regularly is really essential for your safety.

AQUA SHOCK H2O Fresh Water Tank SANITIZER/Disinfectant
  • Economical to use. One (1) ounce per 30 gallons potable water.
  • Does not chlorinate (No THM formation)

How Much Bleach Do You Need?

When planning to sanitize your RV’s water tank, the first thing that might have come to your mind is how much bleach you will need for the process. The answer is actually dependent on the size of the freshwater tank. Here’s a general guideline on the amount of bleach required to sanitize your RV water tank:

40-gal water tank – 1 cup or 240 ml. of bleach

5o-gal water tank – 1 and ¼ cup or 300 ml. of bleach

60-gal water tank – 1 and ½ cup or 360 ml. of bleach

80-gal water tank – 1 and 3/5 cup or 420 ml. of bleach

100-gal water tank – 2 cups or 480 ml. of bleach

Aside from the amount of bleach that you need to use based on the capacity of your water tank, it is also crucial for you to consider some other things. One of which is time. It is because you will need a lot of time for the whole process as it often requires around 6-12 hours.

Also, if you have external or internal water filters, then you have to make sure that you are willing to change them right after sanitizing the tank. Now that you know what you need as well as the specific amount of bleach required for the procedure, it is time to understand the actual steps so you can start to do the sanitizing for your RV’s water tank.

The Actual Steps


Step 1

Drain the water tank partially. Draining it should be done to around half of its capacity. Use pure bleach to sanitize the hose and funnel prior to using them. Allow it to stand for around five minutes then remove the bleach from the funnel.

Use the funnel to pour Clorox® into the fresh water fill. The funnel should also come with a clear and flexible water hose.

Step 2

Refill the tank. Do this until you notice that water begins to come out of the hose or when it is already full. You should then turn off the supply of freshwater. The water pump, on the other hand, should be turned on as a means of drawing water from the freshwater tank.

Step 3

Open all faucets found in your RV, including the one for hot water. You should let them stay open until you smell the Clorox. When that happens, you can turn off the faucets.

Step 4

Turn on the supply of freshwater to your RV then add some gallons of freshwater to the tank. After that, you should start waiting for the completion of the process. If you want to get the best results, then consider waiting at least 3-4 hours to sanitize the water system of your RV completely.

Once the waiting interval is completed, you can drain the tank until it is already empty. Refill it with freshwater. Make sure to do it until it becomes full.

Step 5

The water supply should be turned off while the water pump should be turned on. Begin to flush the water lines. You can do that if you open all the faucets. Leave the faucets that way until you no longer smell the Clorox. However, if the smell still remains after a while, then consider draining the tank again and do the subsequent steps again.

Step 6

Once you no longer smell the Clorox, you can turn the water supply off. Take the external filter out then use a new one to replace it. Also, ensure that you turn off the pump so you can replace your internal filter with a new and fresh cartridge.

When doing this step, dab some petroleum jelly on the filter body’s O-ring. Such will prevent you from having a difficult time taking it out in case you need to change and replace the cartridge.

Now you have fully sanitized the water tank and replaced the filters, allowing the water system and the tank to function at its best again. To sum up the whole process, it involves putting chlorine into the tank, using the water pump as a means of running water through all the pipes, allowing the chlorine to stay in the tank and pipes for around 6-12 hours, then draining the tank then refilling it with freshwater.

It also requires you to flush all the faucets as a means of removing the strong smell of chlorine. Once you have completed all those steps, then you have successfully sanitized the tank.


Water is always an important necessity when you are traveling on your RV. With that said, you really have to make sure that you keep the supply of water in your RV safe and clean. You can do that through regular sanitizing. Ensure that you use the right amount of bleach and do the sanitizing process regularly to get the best results out of it.

Last update on 2021-01-28 at 02:09 / Affiliate links / Images from Amazon Product Advertising API

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