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Is Your Toilet Paper Clogging Your RV Holding Tank?

Don is a retired engineer and long-time motorhome owner who enjoys helping readers deal with the increasingly complex technology of RVs.

Toilet paper on a roll

Toilet paper on a roll

Always Use the Right Toilet Paper

What is the most important thing to keep in your camper? Probably it’s toilet paper—toilet paper designed for use in an RV sewage system.

When most people go to buy toilet paper, they might be bewildered by the variety available. There is the super-cheap single-ply paper that feels like sandpaper, and then there’s the expensive multi-ply super-soft toilet paper. Both of these toilet paper designs will do the job, so to speak, and depending on the materials used by the manufacturer, they may function in your sewage system. But not necessarily.

Now if you live in a home with a septic tank, your first question about the toilet paper you buy should be whether it is labeled “safe to use in septic tanks.”

And if you use an RV, you need to find toilet paper that is safe for RV sewage systems, usually labeled “approved for RV and marine sewage systems.”

Why It's Important for RV Owners

You see, toilet paper for use in an RV must be designed so that it can break down easily and degrade quickly.

If the toilet paper you use in your RV is not the right design, it may not break down fully. Instead, it will settle at the bottom of the black water holding tank. Eventually, you will end up with what many RV owners call a "poop dam" built up in the center of the holding tank.

This buildup in the tank will eventually block the actual waste in the tank from flowing out of the tank when you "dump” your tank. The buildup will often start to solidify. The buildup can get so bad that you will need to hire a contractor with a steam-cleaning apparatus to break down and remove this buildup.

So, make sure the toilet paper you use in your RV is the right design.

Test Your Toilet Paper Yourself

Your toilet paper must break down quickly and not maintain its shape once it becomes wet. In fact, the best toilet paper will break down almost immediately after it gets wet.

You can easily test the toilet paper you are using by doing the following.

  1. Fill a tall glass or bottle with water to the halfway point.
  2. Place a couple of squares of your toilet paper in the water and allow it to sit for a minute.
  3. Then, shake the glass vigorously.

To pass the test, the paper should visibly break down into small pieces.

If your toilet paper passes this test, then you can be confident that you are using a paper that will not cause problems in your black water tank.

Also, Know Your Black Water Holding Tank

Every RV has several holding tanks: one for the fresh water, one for "gray water" (wastewater from sinks and showers), and one for black water (or sewage). This black water tank, because it stores the fecal matter, urine, and toilet paper generated by every visit to the toilet, is the one that absolutely must be managed and cleaned properly by the RV owner.

Your Black Water Tank’s Level Sensors

Because you need to know how close your black water holding tank is to being full, most of these tanks will have level sensors on the inside of the walls. These sensors indicate the level of sewage in the tank, by lighting up a bank of LED lights on a panel for the RV owner to monitor. When the sensor detects moisture at its contacts, it closes a circuit that powers the attached LED. Typically, these sensors are placed to indicate when the black water tank is 1/4 full, 1/2 full, 3/4 full and full.

Black Water Tank Showerheads

Some black water holding tanks will have one or more small water shower heads inside, placed either along the inside upper walls of the tank, or on its ceiling.

The RV owner operates this shower by connecting a fresh water hose to the tank's "shower" connector. The water pressure from the hose will usually wash debris from the walls of the tank, along with any toilet paper that might get hung up on the level sensors.

How You Drain the Black Water Tank

RVs use gravity to drain both waste holding tanks. You connect a sewage hose to the special sewage drain connector in the service area of the RV. This hose is usually a standard flexible 3-inch diameter hose, 10 to 20 feet long, that is designed for draining RV tanks. You connect the other end to a sewage dump site.

Once the hose is connected, you open the main drain valve on the RV, and the tank drains itself through the hose to the dump site.

Cleanup After Draining

Once the tank has emptied itself, there will always be a certain amount of cleanup to perform.

If your black water tank has a shower built into it, the RV owner can connect to it with a water hose and run the shower until the walls of the tank are relatively clean and any residual waste that might still be in the hose is washed away.

Your sewage drain hose will usually have debris, usually toilet paper, inside it, and the best way to clean it is to run water through it with a fresh water hose until it is clean.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.