Dawn Dish Soap In Rv Black Tanks

Maintaining your RV’s black water tank is essential to RV maintenance. One of the best parts about using Dawn dish soap to clean your black tanks is that it’s effective at removing grease and residue buildup. Regularly cleaning your RV water tanks, including the black tank, is vital to prevent fouling and odors. Many RVers have found that putting Dawn dish soap in the black tank is an easy and safe way to deep clean it.

The use of Dawn dish soap for RV black tank cleaning shows the many uses and benefits of Dawn dish soap, as well as proper steps to make sure that Dawn dishwashing is flushed from your tank. Dawn soap is a safe and biodegradable soap to use that will not cause damage to the tank.

It helps clean the sensors and interior walls of your black tank. One of the special things about Dawn dish soap is that it cuts through grease and grime that can build up in tanks from food particles, waste, and toilet paper from your RV toilet. Make sure that the Dawn dish soap you want to clean your RV black tank doesn’t contain bleach or harsh chemicals. When cleaning your RV tanks, fill the black tank with one cup of Dawn dish soap diluted in water.

how to

Let the diluted soap soak in the tank for a few hours before dumping the black tank. Rinse and flush the tank thoroughly after cleaning out RV tanks to remove all soap residue. Using Dawn dish soap, to clean RV black tanks as well as proper flushing, can help keep your RV black tanks clean and keep them functional.

In our guide, you can see how to clean your black tank with dawn dish soap. By the end, you’ll better understand what’s special about Dawn dish soap and ways to clean your black tanks and keep your RV healthy and clean. (Read Do Deer Eat Corn Cobs)

Using Dawn Dish Soap In RV Black Tank

One less glamorous but necessary part of RV life, it’s important to properly clean your RV water waste tank. Cleaning your RV’s black tank regularly helps prevent clogs, bacteria buildup, and foul odors. While many commercial RV tank cleaning products are available, you will find many benefits of using Dawn dish soap for deep cleaning your RV holding tanks.

Benefits Of Using Dawn Dish Soap In RV Black Tank?

Dawn dish soap is often used to clean the RVs’ black and grey water tanks. There are a few reasons why Dawn is a good choice for this cleaning task:

  • It’s a degreaser: Dawn is designed to cut through kitchen grease and soils. This makes it effective at breaking down and dissolving the dirt, grime, and waste that builds up in RV holding tanks. The grease-cutting action helps remove this residue from the tank walls.
  • It’s safe: Dawn dish soap is used on dishes that touch food. As a result, it’s formulated to be safe and biodegradable. Using a small amount of Dawn in your black tank is unlikely to cause issues or tank damage.
  • It’s readily available: Since Dawn is a common household cleaner, Dawn is widely available from most grocery stores and supercenters when you need it. There’s no need to search for specialized RV cleaning products.

Should You Use Chemicals in Your RV Black Tank?

While you can always use store-bought water treatments, some RVers prefer to avoid using any added chemicals. The concern is that chemicals like formaldehyde in many RV tank treatments could damage tank components or vent into the RV’s living space.

Instead, many RV owners stick to thorough flushing and use mild dish soap or borax for periodic deep cleaning. When choosing a dish soap, it’s important to make sure that it does not contain bleach, antibacterial ingredients, or harsh chemicals. Basic Dawn dish soap is one example of plant-derived soap are good options to clean black tanks and keep them functional.

Once you learn how to clean out your tank regularly, you can see how to fill the black tank with ice and dump your tanks once you arrive at your destination. (Read RV Laws California)


Is It Safe to Use Dawn Dish Soap in Your RV Black Tank?

Adding Dawn dish soap to your RV black tank is generally safe and effective. Here are some tips for safely using Dawn:

  • Use a small amount: A cup or two of Dawn diluted in water is sufficient for RV tank cleaning. More is not better.
  • Don’t leave it sitting: After adding dish soap and filling the tank with water, drive around to agitate and empty the tank. Don’t let the diluted soap sit for extended periods.
  • Rinse thoroughly: After draining the soapy water, fill the tank again and rinse until the water runs clear. Repeat as needed to remove all soap residue.
  • Clean regularly: Don’t just rely on Dawn for deep cleaning. Flushing with water and tank treatments in between cleans is still important.

How Much Dawn Dish Soap Do I Need for RV Black Tanks?

For basic RV tank cleaning, you’ll only need about 1-2 cups of Dawn dish soap per treatment. Here are some guidelines:

  • For a 40-gallon black tank, use 1 to 1 1/2 cups of Dawn.
  • For a 50-80 gallon tank, use around 2 cups of Dawn.
  • Use 1-2 cups of Dawn per tank if you have multiple holding tanks.

Make sure to dilute the Dawn in water according to the tank capacity before adding it. This allows the soapy solution to contact all interior tank surfaces fully.

How Often Should You Clean Your RV Black Tank?

RV black tanks should be cleaned regularly to keep them fresh, and you need to deep clean RV black tanks to prevent problem odors.

Here are some general guidelines for cleaning frequency:

  1. If you use an RV occasionally, clean the tanks at least twice a year, if not more.
  2. Clean the black tank monthly or every 3-4 weeks for frequent weekend use.
  3. If you live in the RV full-time, aim to clean the black tank every 2-3 weeks.

Empty your black tank first, and then clean, followed by a tank rinser so that you know that you can use your tanks after any period. Depending on tank capacity, sensor accuracy, and operating conditions, you may need to clean more or less often. Inspect and clean the tank when odors arise to keep your RV black water tank fresh. (Read Air Conditioner Fan Not Blowing)

how to

How To Use Dawn Dish Soap in Your RV Black Tank

Here is a simple process for cleaning your RV holding tank using Dawn:

  1. Ensure tanks are empty: Dump and flush your black and gray tanks before cleaning.
  2. Add Dawn to tank: Pour 1-2 cups of Dawn dish soap at a time down the toilet/black tank valve.
  3. Fill the tank with water: Add enough water to dilute the soap and agitate the tank thoroughly.
  4. Drive and let soak: Drive for 15-20 minutes to wash the tank interior and let soak for up to a few hours.
  5. Empty tank: Drain the soapy water from the black tank completely.
  6. Rinse tank: Refill the tank with fresh water, rinse, and repeat as needed until the water runs clear.
  7. Add tank treatment: Finally, add your usual RV holding tank treatment.

Be sure to rinse the tank to remove all soap residue thoroughly. Avoid letting the diluted Dawn sit in the tank for more than a day, even if it is a soap that will not cause any damage. Clean the black tank regularly and use Dawn to deep clean as needed for best results.


Maintaining your RV’s black water tank is essential to owning a recreational vehicle. Allowing waste to build up in the black tank can lead to foul odors, clogs, and sensor problems. Periodically using Dawn dish soap to deep clean the tank is an easy, affordable, and effective way to keep your black tank functioning properly.

The next time your black tank needs cleaning, fill it with water and add 1-2 cups of Dawn soap. Allow it to soak before dumping and rinsing thoroughly. With simple cleaning steps like Dawn dish soap, you can prevent problems and keep your RV black tank clean. (Read Dometic RV Air Conditioner Not Blowing Cold Air)

FAQs About Using Dawn in RV Black Tanks

Is Dawn better than other RV tank cleaners?

Dawn effectively breaks down gunk and grease in tanks. But a commercial cleaner in your RV black tank will do the same job. Use Dawn dish soap or another alternative for periodic deep cleaning tanks and proper cleaning at regular intervals.

How long should I let Dawn soak in the tank?

A few hours soaking RV black tanks is certainly an effective way to get them clean. However, don’t leave the black tank full of diluted Dawn for more than a day.

Can I use Dawn in my gray tank too?

Yes, you can use a similar method to clean the gray tank with Dawn occasionally. Be sure to rinse thoroughly.

What ratio of Dawn to water should I use?

1-2 cups of Dawn per 40-50 gallons tank capacity is ideal. The soap will dilute further when filled.

Will Dawn damage my tank or septic system?

When appropriately used and rinsed out, Dawn is safe for tanks and septic systems. Avoid overuse.

How can I avoid clogs after using Dawn?

Be sure to thoroughly rinse the tank after cleaning. Follow up with a treatment like biodegradable RV Digest-It to break down any remaining waste.

Dawn Dish Soap In RV Black Tanks (1)

Scroll to Top