How to Sanitize RV Fresh Water Tank

how to sanitize an RV fresh water tank

Your RVs fresh water tank is the only supply of clean cooking, dishwashing, and even drinking water when out on the road. Keeping it as clean as possible will guarantee you less water contamination. 

Even if you have a filter, clean storage tanks are hygienic. There’s no point in letting your tank go filthy just because you think your undercabinet or whole RV filter is up to the job. No matter how good the filter is, it needs all help it can get. Feeding it clean water is a good place to start.

How Do You Sterilise the Fresh Water Tank on RV?

Sanitizing your RV fresh water tank doesn’t need special chemicals or equipment. You can use plain bleach for the job or chlorine tabs specialized in cleaning water.

If you use bleach, ensure you go for a brand without extra additives or fragrances. You don’t want to contaminate your tank with unexpected flavors and smells.

How Much Bleach Do I Need to Sanitize Your Clean Water Tank?

You will need an ounce of bleach for every 8 gallons of water in your tank. To get the perfect amount of bleach, take the overall volume of your tank by 8.

For instance, if your tank can hold 60 gallons:

60/8= 7.5 ounces of bleach

Adding undiluted bleach straight into the water tank could corrode plumbing fixtures, seals, and gaskets. After all, bleach is an acid.

Here are the right steps to follow when adding any sterilization mixture to your RV fresh water tank:

  • Start on an empty freshwater tank.
  • If you have a water heater or water filter, turn them off, drain all the water, and shut off the valves feeding them from the storage tank.
  • Fill your fresh water tank with clean water until it is halfway full
  • Add the correct amount of diluted bleach to the tank
  • Add fresh water to fill your tank to capacity
  • Open all the faucets in the RV and let them run until you smell bleach in the water coming out. This ensures sanitized water flows through all your clean water plumbing.
  • Take your RV for a quick drive. The sloshing around as you drive will mix up the sanitized water spreading the bleach evenly.
  • Let the sanitized water mix sit in the tank for several hours. I would let it sit overnight.
  • Completely drain the tank of the bleached water and flash it with clean water until you can no longer smell bleach in your water.
  • Refill the tank with fresh water and turn on any other water-fed appliances you had shut off before

How to Sanitize RV Fresh Water Tank Without Bleach

If you don’t want to run bleach through your freshwater tank or don’t have bleach nearby, you could opt to use some alternatives. 

It goes on record that bleach is the easiest readily available chemical you can use to sanitize your fresh water tank.

Dedicated RV Water Tank Sanitizer

If you don’t have bleach at hand, you might as well buy dedicated RV fresh water tank sanitizers. Some of the most popular brand names to be on the lookout for are:

  • Camco TastePure Spring Fresh Water System Cleaner
  • 303 RV Wash and Seal
  • Star Brite Aqua Water Tank and System Flush
  • Thetford Store Fresh Water Tank Sanitizer

Sanitizing Your RV Water Tank With Vinegar

Even though vinegar is not as strong as bleach, it is still good enough to clean up your fresh holding tank. Some people feel it is a safer alternative to commercial cleaners and plain bleach.

The only shortcoming is that the water has to heat up to 130 degrees F for vinegar to kill common bacteria like E. Colli, Salmonella, and Listeria.

This alone makes it a less favorable freshwater tank sanitizer. It will, however, do a great job sanitizing your water heater as it will also get rid of mineral deposits while at it.

Can I Use Hydrogen Peroxide to Sanitize My Fresh Water Tank?

Even though Hydrogen Peroxide is a plausible sanitizer, the peroxide you buy from the convenience store or online isn’t strong enough for the job. Retailers sell 3% hydrogen peroxide, and you need something stronger.

If you can lay your hands on a stronger concentration, you will still have to go through a specific neutralization procedure since plain fresh water won’t flush all of it away.

Don’t use hydrogen peroxide as an alternative sanitizer for your RV fresh water tank.

How Often Should You Sanitize Your RV Water Tank?

It depends on how often you use your water tank and how clean your local water supply is. 

If you refill from a treated municipal water outlet, you can stretch it for longer as long as you pull water out of your tank very often. Don’t let the water sit in the tank for over a week, as this gives microbes a chance to fester.

ProTip: Full-time bundockers who are always pulling from their freshwater tank can go for up to three years without sanitizing their freshwater tank, and it will still not make their water stale

If you park your RV for winter or leave the water in the tank unchanged for over two months, consider sterilizing it first before using it again.

You should also sanitize frequently if you refill with stream water, well water, or any other untreated water source.

Check this too: How to Heat an RV Without Propane

Regardless of where you get your water or how often you empty the tank, consider sanitizing your tank at least twice a year. Do it more often if your water supply is questionable. Sanitize it every time you come back after parking the RV for over a month.

It would help if you also sterilized the water tank whenever you get strange odors from your freshwater.