Monday, September 25, 2023


Ask Dave: I want to store water for emergencies. How do I keep it fresh?

Dear Dave,
I live in a 5th wheel full time in Florida. I am, for now, stationary. My question is concerning the fresh water tank. I want to store water for emergencies when we lose city water. What is the best way to keep water in the tank fresh? My theory is to fill the tank all the way to eliminate any air in the tank. This way bacteria cannot grow because there is no oxygen. Is this correct? Or is there a better way? —Roy

Dear Roy,
Even if you fill the fresh water tank, there will still be air present because it has a vent tube to eliminate a vacuum when draining or supplying the water pump. Keeping the water fresh and non-contaminated are two different issues and will depend on your water source. Conditioned water from a municipal source will be easier to do both with, as well water will have minerals and some contaminants that will start to act faster.

Almost any type of water being stored in a plastic holding tank will start to develop a taste or smell over a period of time, especially at higher temperatures. This doesn’t mean it’s contaminated—it’s just not fresh.

The CDC has guidelines for storing water for emergencies in a residential situation that I think would also apply for an RV.

Their first recommendation is to purchase purified water from a store in sealed containers. This will last much longer. These can be 1 gallon, 5 gallon, or even larger containers available at camping stores. Then it’s just a matter of finding the space to store them! More on CDC recommendations later…

Identify your water usage

Keep in mind there are different ways you use water when RVing. Drinking water needs to be much purer than water used for flushing the toilet. You might be able to store enough bottled water for drinking and washing hands, while using the water in the fresh water tank for showering and flushing the toilet. However, in the case of a water emergency, showering is not a priority like staying hydrated and going to the bathroom is. Plus, a shower can deplete a water supply in a hurry. It’s not ideal, but you can sponge bathe with limited water and even baby wipes.

Since you are stationary, maybe a couple of 5-gallon air-tight water jugs from the reverse osmosis machine at your local grocery store stored under the bed or in a compartment would hold you over. On top of that, have a full fresh water tank.

Follow these suggestions from the CDC to store water for emergencies:

  • Replace non-store-bought water every six months.
  • Store a bottle of unscented liquid household chlorine bleach (label should say it contains between 5% and 9% of sodium hypochlorite) to disinfect your water, if necessary, and to use for general cleaning and sanitizing.
  • If you don’t have safe bottled water, you should boil your water to make it safe to drink. Boiling is the surest method to kill disease-causing organisms, including viruses, bacteria, and parasites. If you don’t have safe bottled water and if boiling is not possible, you often can make small quantities of filtered and settled water safer to drink by using a chemical disinfectant such as unscented household chlorine bleach.
  • Disinfectants can kill most harmful or disease-causing viruses and bacteria, but are not as effective in controlling more resistant organisms, such as the parasites Cryptosporidium and Giardia. Chlorine dioxide tablets can be effective against Cryptosporidium if the manufacturer’s instructions are followed correctly.
  • Store any water containers out of direct sunlight and in temperatures between 50-70 degrees. This is usually not possible in a fresh water tank in an RV but can be done inside the rig.

I have not encountered a water emergency while RVing. However, I have gone through two flooding disasters in my hometown that shut down the water supply and flooded the waste treatment plant in a local town. Since we live in the frozen tundra of the upper Midwest, we have had several below-zero conditions that have caused frozen or broken water supply lines to our house. I was on the City Council and fortunately we had been educated and trained for not only emergency protocol but also emergency preparedness, which included knowing how to store water for emergencies. I applaud your efforts to do the same.

There are several over-the-counter products that claim to purify and freshen water with pills or liquid additives. However, while doing research on another post I came across the Clearsource Ultra, which looks to be a good choice as well. Since it has been below freezing the past several months I have not had the opportunity to test it, but I will this spring.

Note: If you’re in the Raleigh, NC, area, join me this week at the NC RV Dealers Raleigh Show, Feb. 18-20, at the NC State Fairgrounds. We have three days’ worth of seminars.

I will also be at the Harrisburg-Pennsylvania RV Super Show in Harrisburg from Feb. 25-27.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

Read more from Dave here


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Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.


  1. We make sure to keep the water that is in the rv fresh water tank as fresh as possible. We use the tank water for our dishwasher and washing machine. Normally, we can cycle the tank every week or two. If it goes longer than that, we drain the tank and refill

  2. maybe a couple of 5-gallon air-tight water jugs from the reverse osmosis machine at your local grocery store stored under the bed or in a compartment”

    They also make 3-gal versions of these heavy duty water jugs. They’re much easier to store, move, and pour from.

    If you add chlorine to your water tank, you can remove the chlorine taste by adding vitamin C to a pitcher of water before drinking it. Kool-aid or similar products with vitamin C do the same thing. Here’s an authoritative link but many web sites have similar info that’s easier to read.

  3. For many years we have always kept our FW tank full and lived off of it when on the road and boondocking. This turns it over at least once a week when we can find municipal water or equivalent (the park I am in has the well water certified on a regular basis). When stationary for a couple of months we will use the tank water for a few days, and then fill it up again to add fresh water that is chlorinated. Having drunk chlorinated water most of our lives, that is how we expect it to taste.

  4. Don’t drink from your water tank. Also, when on city water we use a large carbon block filter. I keep a gallon jug filled with this water for the ice maker and Keurig. The jug is made of plastic and gets replaced about twice a year…..:)

  5. Our city had some fresh water plumbing issues years ago and made the water taste funny even though it was safe to drink. We started buying and refilling gallon jugs at the grocery store to drink while waiting for the city water to get better. We got used to it and kept it up for years afterward until we moved out of the city and connected to a different water supply.


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