Keeping Your RV Water Tanks Fresh: 9 Tips

RV Owners


Even the smallest RV can offer all of the modern conveniences of home: electricity, heat, air conditioning, and running water. However, the water system in your RV is different from the one in your home. Instead of draining into a municipal sewer or septic system, the wastewater in your RV drains into one of two holding tanks. Not only do these tanks need to be emptied regularly to prevent them from overflowing, but they also need to be maintained to keep them from developing any offensive odors.

You’ve got a total of three RV water tanks in your motorhome. The first is your potable or freshwater tank. This is water that you can drink, cook, or bathe with. Second is a grey water tank, which contains wastewater from sinks and the shower. Finally, there’s a black water, or wastewater tank, which holds everything you flush down your toilet.

Since there’s nothing like a pervasive stink to ruin an otherwise awesome camping trip, it’s absolutely essential to keep your tanks clean and take care of small odors before they become big ones.

How can you keep your RV water tanks clean and your RV smelling fresh? Here are nine helpful tips.

1. The Potable Hose is for Potable Water Only

It may seem obvious, but it’s worth a mention: never use your potable water hose to drain your grey water tank.

an RV parked by the shore

2. Sanitize Your Freshwater Tank

If your freshwater tank is older, or if it’s been sitting in your stored RV for a while, it may begin to harbor bacteria. As a result, the tank can develop an unpleasant smell or make your drinking water taste bad. You can solve this problem with some old-fashioned bleach. While you never want to pour straight bleach into your fresh water tank, you do want to use a diluted bleach solution. Here’s a foolproof method to sanitize your fresh water tank and eliminate any off-taste or funky smells.

  • Mix one cup of bleach to four gallons of water for a 40-gallon tank, one and a half cups of bleach to six gallons of water for a 60-gallon tank, and two cups of bleach to eight gallons of water for a 100-gallon tank.
  • Add the bleach solution to your tank, then fill it up all the way with fresh water.
  • Run all of the sinks and faucets, one at a time, until you smell bleach through each one and the tank is empty.
  • Once it’s empty, fill up the tank with fresh water and let it sit overnight.
  • The next day, drain the tank through all of the faucets again, then repeat filling and draining with fresh water three more times. If you can still smell bleach, repeat the freshwater process until you it’s gone.

3. Remove the Sink Stink

For getting rid of odd odors from the kitchen or bathroom sinks, try pouring half a can of orange soda down the drain, then rinse with some water from the tap. The fizz will help clean off some of the sludge, and the orange scent can help to cover up any less-than-savory smells.

4. Don’t Let Food Fall Down the Drain

Use a mesh strainer basket in your kitchen sink to catch bits of food before they wash down the drain and into the grey water tank. This will go a long way toward keeping your tank fresh and odor free.

5. Prevent Odors with Baking Soda

Every time you empty your grey water tank, put a spoonful or two of baking soda in the kitchen sink and rinse it with some hot water. This can really help to keep odors from developing.

6. Chemicals for the Black Tanks

There are a number of products on the market that are designed to help control odors in both your grey water tank and your black water tank. If odor starts to become a problem, using one of these may be the simplest way to keep your RV free of bad smells.

7. Keep that Black Tank Valve Closed!

When you’re hooked up to a sewer connection at a campsite, keep your black tank valve closed. It may be tempting to just leave the valve open, but this is a mistake. What happens when you leave the valve open is that all of the water waste will drain from your tank, but the solid waste will not. Eventually, you’ll have a black water tank full of solid waste that will not only smell quite foul but will need to be cleaned out. Now that’s a nasty job!

8. Give it a Good Cleaning

Every once in a while (at least once a season), it’s a good idea to clean your black water tank really well to remove any solid waste that might have built up along the inside.

  • Empty your tank at a dump station, then take an ordinary garden hose and push it down through the toilet. If your RV is like most, the black water tank is located directly under your toilet.
  • Turn the water for the hose on all the way and move it around so the spray hits as much of the inside of the black water tank as possible.
  • When the tank is full (or close to full), empty it again.
  • You can repeat this a second or third time if it’s been a while since you cleaned out your black water tank, or if you’ve been having issues with odors or backups.

9. Take it for a Drive

If you’ve done the above procedure and still have an odor or waste stuck to the inside of the tank, try filling it up with the garden hose again and taking your RV for a drive before draining your tank. This can create more agitation and hopefully loosen any residue.

If any of your water tanks start to pick up bad odors, try one of these tips to clean it up and keep your RV smelling good.

While tanks that are very old may eventually need to be replaced, a bad odor alone is not reason enough to buy a new one. Properly cleaning the fresh, grey, and black RV water tanks may not be a glamorous job, but it’s the only way to keep your RV smelling continually fresh.