Thursday, February 2, 2023


Easy RV freshwater hack for safe drinking water

By Cheri Sicard
You might be putting drinkable water into your RV freshwater tank, but is it really safe and drinkable when it comes out of your RV’s faucet? Do you know what’s lurking in your dark, wet, warm RV freshwater tank? That environment is perfect for bacteria to grow. Eeewwww!

You really should disinfect your freshwater tank every six months. It might seem like a daunting and intimidating job, but it does not need to be. Robin Barrett from Creativity RV is here to help!

So what does it take to disinfect an RV freshwater tank? Bleach. But just a little bit.

Robin says you should consult your RV’s manual for how much to add. If, however, you don’t have such a manual (no manual came with my used RV), you will need to figure out the proper amount depending on the size of your freshwater tank.

Robin says a good rule of thumb is to add 1/4 cup of liquid bleach for every 16 gallons of fresh water. For the size tank Robin is working on in the video, she would use 3 cups of liquid bleach.

However, this is where the hack comes in.

Liquid bleach is not a handy item to carry in the RV. It’s heavy. It takes up a lot of space. And it could spill. Not only that, siphoning the liquid into your freshwater tank without spilling any can be a pain in the you-know-where.

Robin discovered a better alternative in dry bleach tablets!

These are concentrated dry bleach tablets. Sixteen tablets are the equivalent of 1 gallon of bleach. But they weigh a heck of a lot less and don’t take up nearly as much room. Plus, there is no spillage danger.

These tablets create liquid bleach when mixed with water. So all Robin does is add a tablet to the hose and run fresh water into the tank. It’s brilliant as the hose will also get a bleach rinse and disinfecting!

You will want to do this job when you have access to fresh water and sewer. Here are the steps to disinfecting your RV’s freshwater tank (watch the video of a demonstration).

  • Open the valve and drain the freshwater tank.
  • Robin chose to refill the tank and run the water through all the pipes and faucets (honestly, I am not sure what the purpose of this was, and she does treat it as an option).
  • She then refilled the tank WITH the bleach tablets in the hose.
  • She then let it sit for 3 hours so the bleach can do its disinfecting magic. Don’t leave it longer as bleach can ruin your seals with time. If you can, drive around with the bleach water in the tank.
  • Before you empty the tank, run the bleach water through all your water lines and faucets to disinfect them.
  • Empty the freshwater tank again.
  • Refill the tank, run it through the lines, and dump it again two or three times more. Or until you no longer smell bleach.

Be sure to see Robin’s follow-up video on cleaning your tank sensors, which you can do at the same time.



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Jim Rodan
1 month ago

The instructions are poorly written. There is no reason to “flush” the tank and lines before bleaching – waste of water. The bleach soak should be more like 10-12 hours. Overnight works fine. The bleached water should be run into all the lines inside and out BEFORE the soak, not after, so they get sanitized. Then dump and refill with fresh water, rinse out all the lines and dump and fill with fresh water, and you are good to go. There is no need to do this repeatedly as once the bleached water is drained out there is just a small bit of bleach left and mainly in the lines which are easily flushed out. The tank is rinsed out adequately with the first refill and dump (30 to 50 gallons fresh vs. perhaps a few cups of fully diluted bleaching water left – and this is all flushed out with the first dump after the rinse run).

Last edited 1 month ago by Jim Rodan
William Anderson
1 month ago


Watching this, I never knew that there were bleach tablets for laundry. I did know about sodium hypochlorite tablets for swimming pools.

One note about the procedure sequence. She should circulate the bleach sanitizing solution from the water tank through the pipes to all of the fixtures before waiting the 3 hours. Otherwise, the pipes themselves are not sanitized. Also when doing this, one should remove any carbon/charcoal filters as these will remove the chlorine bleach.

This is a neat way of doing this using a product that is easy to store.

Rick Wilkins
1 month ago

I would be very careful using bleach tablets. All the ones I looked at on Amazon following the link provided above indicate that they are not to be used for cleaning food safe surfaces or for purifying drinking water. There are many different types of “Bleach products” and they are not all the same chemical composition.

1 month ago
Reply to  Rick Wilkins

This isn’t to purify your water. It’s about cleaning, sanitizing your tank.

Rick Wilkins
1 month ago
Reply to  Cee

I agree, but the inside of your fresh water tank and fresh water pipes are essentially food safe surfaces. I would be concerned with the residue potentially left behind and contaminating those surfaces.

1 month ago
Reply to  Rick Wilkins

You’re right, you need to be aware of what you are purchasing and is it the right product for the job ie.ingredients you don’t want. And some labeling is not forth coming. I don’t drink water from my fresh water tank but I do use it for showers.

Jim Johnson
1 month ago

One of the things that bothers me about maintaining an RV is the volume of potable water that is used for nothing more than flushing supply and waste systems. That water is either dumped on the ground (supply side) or into a septic system (waste side). We winter in a drought stricken region where water is a precious commodity.

1 month ago

RV holding tanks are a lot of work! We bought our 20 foot Catalina used. It came with no manual. Videos like this one are so helpful. We are still trying to figure out our water heater. Access to the heater is under the dinette bench. The panel was screwed on tightly and looked like it had never been accessed in the 10 years before we bought it. This is all new to us as we had only had a pop up camper with no water heater before the Catalina. Learn as you go! We did invest in an inexpensive but very effective ceramic water filter system that we call “Fake Berkey.” Got it on eBay from a survivalist for lots cheaper than a real Berkey. Thank you for this video.

1 month ago

Three cups of bleach is 12, 1/4 cups. 12 times 16 gallons is 192 gallons. Double the dose needed for a 100 gallon tank. Using 4 cups would be enough for 256 gallons.
Also, it does not say what the concentration of sodium hypochlorite each tablet creates in a gallon of water. Normal liquid ‘name brand bleach’ contains 7-71/2 % of the active ingredient. Most of the generic or off brands only have a 3-5% concentration.
Looking at the bleach tablets, most are scented.

1 month ago
Reply to  Bob

All good points. I didn’t want to do the math, but I also noticed there was something terribly wrong!

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