How to Clean an RV Holding Tank? - A Detailed Guide (2023)

In most cases, recreational vehicles come in two types of holding tanks on board: gray and black water tanks. A gray tank should catch the water that goes down the drain of the RV’S sinks and shower, while the black one will be responsible for holding the wastewater from the RV’s toilet.

Learning how to clean an RV holding tank is a matter on every RV owner’s mind, but wastewater disposal is a task that few want to think about, as it is probably the least glamorous part of RV life.

Just like cleaning a bathroom at your home is a crucial chore, cleaning the RV’s sewer system is essential to prevent unpleasant odors and clogs in your system and keep tank sensors working correctly.

Table of Contents

  • How to Clean and Flush the RV Tank
    • Step 1: Drain Your Tank
    • Step 2. Get Rid Of Buildup And Debris From Your Tank(s)
    • Step 3: Add Water to Cover the Bottom of Your Tank
  • Deep Clean and Treat Your Tank to Keep It Clean
    • 3. The GEO Method
  • Bonus Tips to Keep Your RV Black Tank Clean
  • FAQs
  • The Bottom Line

How to Clean and Flush the RV Tank

How to Clean an RV Holding Tank? - A Detailed Guide (1)

Cleaning and flushing RV black tanks are not daunting tasks, although it can be one of the most unpleasant and intimidating for RVers who are unfamiliar with it. But with just a few practices, it will soon become a basic habit.

Step 1: Drain Your Tank

How to Clean an RV Holding Tank? - A Detailed Guide (2)

Start by connecting an RV sewer hose to the tank valve and the other end to the dumping hole. After that, open the tank valve to let the contents flow into the sewer or septic systems.

Dumping the RV black tank when it’s at least half full is wise. In that way, it will allow the liquids to drain and waste or other solids to float correctly.

If you are emptying black water tank RV when it is less than half full, adding a little water first is necessary.

Step 2. Get Rid Of Buildup And Debris From Your Tank(s)

When flushing your tank, you will have to do some essential maintenance, including removing buildup and debris that is formed in your tanks. Here are a few ways that allow you to get the job done.

  • Use a Macerator

You can use a macerator which takes advantage of high-velocity water pressure to shoot jets. It will help you remove debris and build up the inside of the hoses and tanks easily and quickly.

Basically, it will liquify any waste or debris and allow them to be drained out of your RV tank like water.

  • Use a Tank Rinser
(Video) RV Black Tank Cleaning, Maintenance, Tips & Tricks - The Original Black Tank Master Class

Tank rinsers are available in two varieties: One can be installed into the RV tank permanently, while the other can be set into the tank each time you want to flush it.

The permanent rinser can rotate in 360 to shoot water at high pressures, while the other features a wand-style hand-operated device that connects to utility or garden hoses.

  • Use a Flush Valve

The flush valve is also the best way to take care of the tank. These valves will connect the flush valve barrel to garden or utility hoses, allowing you to choose “tank” or “hose” settings.

Flush valves also feature backflow prevention so that your clean water source/hose always avoids any risk of contamination.

Step 3: Add Water to Cover the Bottom of Your Tank

The black flushing will end once you have dumped it, gotten rid of any build-up or debris, and filled up the bottom with clean water. In that way, your system will be kept functioning correctly and avoid any damage.

Usually, 4-5 liters of water will work well. However, you may also need to use more water, depending on the size and shape of the tank.

Deep Clean and Treat Your Tank to Keep It Clean

How to Clean an RV Holding Tank? - A Detailed Guide (3)

If you haven’t cleaned your RV tanks in one or two years, check out these other solutions below. They will also be beneficial in keeping your RV black tanks clean and the monitor system reading accurately.

1. Use Ice Cubes & Non-antibacterial Detergent

This RV black water tank treatment involves adding two to three bags of ice cubes into your tank and driving.

In addition, we recommend adding dishwashing detergent (a quarter cup, and choosing a non-antibacterial variety) and water (two gallons) to your tank, along with ice cubes. We recommend detergents from Joy or Dawn when it comes to liquid soap.

You simply drive for two to four hours before dumping and flushing your tank at a full-hookup campsite.

Generally, the right amount of ice cubes may dislodge matter stuck on your tank side walls. However, you should try the following ways to save the ice for your favorite beverage.

2. Baker’s Yeast & Peroxide

Baker’s yeast and peroxide also work well in removing odor or solids in your black tank. All you need to do is add one gallon of water to your empty tank, ten ounces of peroxide, and four ounces of yeast.

Keep driving while a mixture of water, peroxide, and yeast splashes throughout the tank.

Once you have reached a camping location, you need to empty your tank and refill it with water. Afterward, add the normal black tank treatment additive.

(Video) RV Black and Grey Tank Cleaning and Maintenance | Geo Method | Full Time RV Living

In our experience, this approach effectively eliminates odor and solids, but not paper.

3. The GEO Method

The Geo Method is a manner of treating and maintaining an RV’s black and gray tanks by using a combination of laundry detergent, water softener, plenty of water, and sometimes chlorine bleach as a means of odor control. Many RV owners utilize it with much success.

There are various ways to go regarding the GEO method, and we will include all the most common products utilized.

  • Step 1: Dissolve water softener (two cups) in hot water (one or two gallons). Many RIVers preferred the powdered Calgon water softener for this project. You will do this for both tanks, so you must make two “batches” of this solution.
  • Step 2: Pour this solution into the toilet for your black tank and your shower or sink for your gray tank. Your water softener will keep solids or toilet paper from sticking to the sides of your tanks, which is essential for accurate monitoring readings.
  • Step 3: Add a cup of Dawn soap or laundry detergent (eco-friendly version) to your black tank. You can expect it to help clean and deodorize your black tank.
  • Some RVers also use a combination of Borax and Dawn to clean RV tanks. If you want to go this way, use 1/4 cup Borax to your RV’s tank along with Dawn soap. Borax will serve as a great cleaning agent.
  • Step 4: Use the tank normally and empty it when it is between 2/3 full to full.

Use the Geo Method every time you clean a holding tank in an RV.

Bonus Tips to Keep Your RV Black Tank Clean

  • Dump and clean black tank on the RV before the tank is over 2/3 of the way full.
  • Wear plastic gloves before doing this task. In that way, you’ll eliminate any risk of spreading bacteria.
  • We recommend beginning with the black tank every time you flush the RV tanks.
  • Take advantage of the soapy water from your gray tank to clean black water residue.
  • Pick septic-safe toilet paper.
  • Select a cleaning treatment that works best for you, and use it each time after dumping the black tank.
  • Avoid utilizing freshwater hoses for any kind of black water tank or sewage hose rinsing.
  • Sanitize RV black water tank with earth-safe RV black tank cleaner, which shows that you are being kind to the septic systems and our planet.
  • Always dump your tanks into the drainage pipes, and clean up after yourself.
  • Carry a clean, spare hose along when you visit the dumpsite in case they do not have any available.
  • Educate grandchildren, little ones, and visitors on the importance of using an RV toilet responsibly.


How to Clean an RV Holding Tank? - A Detailed Guide (4)

1. Why Clean The RV Holding Tanks?

When you clean your holding tanks, you also clean the RV sensors.

Sludge, toilet paper, and wayward hygiene products may cover up sensors, resulting in you getting false positive readings. Also, once your sensors are off, you may be waiting too long or emptying too early.

2. Does the Geo Method Break Down The Solid Solid Waste?

Although the Geo method is not intended to break down the solid waste, it can eliminate odor by cleaning the tank effectively.

The primary purpose of this method is to rinse the waste down the line effectively and keep holding the tank surfaces free of gunk build-up.

3. How Often Should You Flush Your Black Tank?

There is no exact answer to this question as it depends on various factors, such as what size your tanks are or how many passengers are using them.

Many RV owners obey the 2/3 of full rule, while others wait until their RV tanks are almost full.

(Video) RV Black Tank Cleaning Tips You SHOULD Be Doing! SEE UPDATED VIDEO IN DESCRIPTION!

If you travel alone or with one other person, flushing your tanks once a week is reasonable. But if you’re traveling with a larger group, you may want to flush the RV tanks once every few days or even daily.

4. How to Make a Homemade RV Black Water Tank Cleaner?

You can refer to the following recipe to make homemade RV black water tank cleaner:

  • Two cups of powdered water softener, like Calgon Water Softener
  • One cup of Dawn dish soap or powdered laundry detergent
  • One splash of household bleach
  • One hot gallon of water

The Bottom Line

We hope you already know how to clean an RV holding tank by now.

Making a routine with cleaning your RV holding tank is the best way to reduce odors, prevent damage, and avoid costly repairs.

Performing RV black water tank cleaning will help maintain the integrity of the RV tank while creating a much better experience for you and the passengers.

Thank you for reading!

(Video) RV holding tank cleaning, maintenance and tips with Sue from Royal Flush RV!

5/5 - (2 votes)

How to Clean an RV Holding Tank? - A Detailed Guide (5)


Glen’s a camping addict since way back when, a time he could barely remember. He loves tools, equipment, gears, accessories, and doing repair on his RV. He’s a confessed DIYer, performing even the maintenance of his RV. Glen also loves dressing up his recreational vehicle to keep it in style.


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