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POOP Pyramids and the STINKY TRUTH About RV Toilet Paper and Black Tank Sensors

| Updated Apr 23, 2024

This may be an indelicate subject, but the matter of choosing the right RV toilet paper and understanding your RV's black tank sensors are critically important to your enjoyment of the RV Lifestyle…

So, being as tactful as I can, let's talk about this.

If you've been frustrated that your black tank sensors don't seem to be giving accurate readings, listen up. As you are about to learn, the sensors are probably just fine. 

It's the RV toilet paper that is causing the issues.

RV toilet paper branded as such gets a bad reputation.  It's expensive in comparison to household toilet paper, and frankly, household toilet paper is a lot softer and more convenient to use.

So do you really need to buy toilet paper specifically made for RV use?

In short, yes, you do. However, let’s talk about why you need this and what to look for.

What Is RV Toilet Paper, and Why Does It Matter?

RV toilet paper is specifically designed for quick disintegration, particularly in a black tank.

Where regular toilet paper has many layers pressed together, RV toilet paper has many chunks bonded together. This difference allows the sheets to break apart in your black tank quickly.

How fast the RV toilet paper breaks down can dramatically affect how often you need to empty your black tank. It also determines some of the cleaning factors for your black tank. After all, you don’t want to clean that tank more often than necessary.

One positive thing about RV toilet paper is its environmental friendliness. Many brands are entirely biodegradable. Others use recycled materials.

Selecting an RV Toilet Paper

RV toilet paper is significantly different from regular toilet paper, and many people find the initial difference jarring. You should think of it as part of the experience, as Jennifer and I do.

The key feature when you’re choosing an RV toilet paper is strength. You don’t want it to fall apart while using it. Fortunately, RV toilet paper manufacturers know this.

Another critical factor is absorbency. If you desire to test this, see how much spilled liquid an RV toilet paper picks up from a counter.

The final technical thing you should look for is dissolvability. If you find the paper does not dissolve quickly after use, it will clog your black tank. Either the toilet paper must change, or your black tank treatments do at that point.

Those are all the measurable factors of RV toilet paper. However, you should also try a few different brands for comfort. You are the one who must use this toilet paper, and it should not be something you dread.

The one we have settled on in our RV is Scott Rapid-Dissolving Toilet Paper made for RVs and Boats. You can get 48 rolls for a good price on Amazon. For other options suggested by our RV Lifestyle community, read The Best Toilet Paper for RVs.

photo of fast dissolving rv toilet paper
This is our favorite brand of RV toilet paper

The Home Toilet Paper Test

Generally, we do not recommend trying to use regular home toilet paper in your RV. The chance of clogs and backed up toilets that ruin your trip is simply too great. However, you can use this test to see how your RV toilet paper stacks up.

To begin, find a container with a lid that you can shake. Then fill the container roughly three-quarters full of water. From there, add the number of toilet paper squares you use in a typical wipe. Then shake vigorously.

If the toilet paper dissolves within about ten seconds, it’s suitable for use in your RV.

This quick dissolution means that the liquid materials in your black tank can dissolve the toilet paper before it creates a mess.

If the toilet paper does not dissolve within the allotted ten seconds, you should keep that toilet paper far away from your RV’s black tank. That toilet paper will clump, not dissolve, and cause you black tank headaches.

But what about this Poop Pyramid? Understanding the RV Black Tank

Unfortunately, it’s just like what it sounds like: a pile of poop. Human waste piles up in your RV tank and pretty much becomes a solid mass that refuses to flow out of your stinky slinky.

You'll need to learn how to avoid the dreaded poop pyramid and How to Unclog an RV Toilet (7 Easy Methods & Tips).

RV waste systems vary significantly from their home counterparts. The black tank is your primary concern, but all modern RVs also have a grey water holding tank. The grey water tank holds the liquid from showers and sinks.

Each of these tanks must be emptied. However, RVs do not have mechanical assistance for emptying these tanks. It depends on you hooking up the hoses correctly. It also depends on gravity. As you know, gravity is not the most discerning force.

That is why the toilet paper you use in an RV must dissolve. Clumps are heavier, regardless of the composition. If things do clump, you could have solids left in your black tank even after emptying. That can give you false readings on the black tank sensors.

Assuming you have the right RV toilet paper and everything has dissolved appropriately, emptying the black tank into a dump station should be a simple matter of hooking it up and letting it run until you cannot hear any more liquid going down the pipe at the dump station.

Always drain the black water tank first. Then empty the grey water tank. Not only does this get out grey wastewater, but also the liquid from the grey tank also flushes any leftover solids from your sewage line.

The Problem with RV Black Tank Sensors

Unfortunately, sometimes using RV toilet paper is not enough to prevent black tank issues. In particular, the sensors of your black tank can cause lots of headaches.

Typically, black tank sensors are placed up the sidewall of the black tank at the empty, one-third, two-thirds, and full marks. Theoretically, these black tank sensors trip when the black tank waste reaches each level, letting you know how long until you need to find a dump station.

Sometimes, the black tank sensors do not work like they are supposed to. Rarely is this an electrical issue. More often, the faulty readings are due to waste buildup on the sensors. This buildup can happen quickly when you do not use RV toilet paper.

The first thing you can try is adding a tablespoon or so of Dawn dishwasher soap to your tank. This dish solution breaks down grease, which in turn breaks up clumps of waste. Combined with a lot of water, it can work miracles with the black water sensors.

The next step is trying a digestant, which breaks down most varieties of waste found in your black tank. These are mixed with about half a tank of water and left to sit to break down the tank contents.

Most do double duty as a deodorizer.

A good deodorizer/digestant should be regularly added to the black water tank to control odor and break down any solids.

image of a digestant to clean an rv black tank sensors
This is the product we use to deodorize and dissolve solids that can clog our RV black tank sensor. It's called Happy Camper and it costs about $55 for a bucket that lasts for 64 reatments.

We have had great success with a product called Happy Camper. One scoop treats about 40 gallons of waste in a black water tank. Of all the products we've tried, this is the best one. We get the bucket that has 64 treatments.

If that still does not work, you can try adding a little movement. Some people swear by filling the tank half full of water, add the recommended amount of digestant, and then add a bag of ice. All you need to do is drive around a little bit, and the ice should scrape off the stuck waste, they say.  Then empty the tanks at an RV dump station (but I hate to even mention this as it really doesn't work).

photo of rv dump station
An RV dump station sign on the edge of a building.

If your black tank sensors are still not reading correctly, you may need professional tank cleaning. It may also be the actual black tank sensors, though that is the exception to the norm.

In any case, if in doubt, take your RV to a professional maintenance shop for their opinion. And always use RV or marine toilet paper.

But if you really want a heated argument between RVers – just mention not to put paper in an RV toilet (throw it away instead).

RV Black Tank Accessories: 7 Must-Haves for Dumping & Odors

We've put together a comprehensive list of must-have products for dealing with your black tank. From connection accessories to cleaning and odor control, we cover everything you might need (and want!) to deal with your waste-holding tank. Keep reading…

POOP Pyramids and the STINKY TRUTH About RV Toilet Paper and Black Tank Sensors 1

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Mike Wendland

Published on 2024-02-04

Mike Wendland is a multiple Emmy-award-winning Journalist, Podcaster, YouTuber, and Blogger, who has traveled with his wife, Jennifer, all over North America in an RV, sharing adventures and reviewing RV, Camping, Outdoor, Travel and Tech Gear for the past 12 years. They are leading industry experts in RV living and have written 18 travel books.

14 Responses to “POOP Pyramids and the STINKY TRUTH About RV Toilet Paper and Black Tank Sensors”

July 27, 2022at11:38 am, RV Black Tank Advice From The "RV Proctologist" | RV Lifestyle said:

[…] But it probably all goes back to that, I’m sure. But as I understand it, stuff sticks to those black tank sensors, and that’s what causes that. Is there a fix for that, an easy fix that we can […]


October 22, 2020at3:33 pm, B Travis said:

When you kids decide to keep an RV over a couple of years, then see how those tanks sensors work. But still good info on the things one should do, but don’t count on it for older tanks.


October 22, 2020at3:16 pm, Mel said:

I was suggest that you look into a product called tank tech RX. This is amazing stuff. It’s a probiotic that eats up the odor, paper, and all waste products. The company put a roll of toilet paper in a tank with the tank tech and 16 days later the paper was completely dissolved. I’ve use this product for a couple of years and really really highly recommend it. You don’t completely empty the tank as it is a live organism and will start growing again.


October 22, 2020at3:10 pm, Dan Johnston said:

My camper has been in covered storage (local storage facility). I checked on it yesterday and found mold on the cabinets meaning it is probably all over. I was thinking of diluted bleach, with spray bottle. Your thoughts?


October 23, 2020at2:13 pm, Kathy Niemeyer said:

Dan, you can use Clorox wipes and clean up the mold. Did you put Damp Rid in your unit when you put in storage? This will help with moisture and mold. Open all your cabinets and refrigerator when you store.


October 22, 2020at2:57 pm, Beth said:

I also use regular Scotts. And following the practice on many sailboats, unless it is really nasty it goes in the trash, not the toilet. I use digester regularly. The only time I had a tank sensor problem, I did the bag of ice thing, problem solved. (And I’ve sometimes done that anyway, at the end of a season, as I have no way to powerwash the tank.)


October 22, 2020at9:08 am, PHILIP KANE said:

I use Scott’s regular TP and it breaks down fine. I also use this stuff: TankTechsRx – RV Holding Tank Treatment & Cleaner. Our RV has a built-in black tank hose/cleaner, I haven’t had any trouble with this method. We go out for 2-5 days, some times at an RV park and mostly at the Desert. We do keep an eye on how many times we use the toilet. By the time we get back and dump the tanks they have been blended up so much that is also why I think we haven’t had any problems.


October 22, 2020at9:00 am, Stanley said:

Prices for RV TP are higher than indicated. Currently (Oct 2020), Amazon wants $50 for 48 rolls!!


October 22, 2020at8:40 am, James said:

My wife and I are new to the rv lifestyle this year. We live full time in our motorhome. We tried some different brands, and quickly realized the differences. Nothing like using “quick dissolve” and feeling your finger poking through while wiping…??


October 22, 2020at10:46 am, Grtbluyonder said:

Ad announcing “new breakthrough in RV toilet tissue”


October 22, 2020at8:19 am, Allan Bowman said:

A sailboat I once chartered had perfect tank sensors. They were based on nothing more than a small air pump (like a fish tank air pump) pushing air through a small tube that was installed with its opening about 1/4 inch from the bottom of each tank (grey, fresh, and black). A pressure gauge calibrated from 0 to 100% was in the pump output and on the display panel . Pressing the “black” button on the display caused the air to flow to the black tank tube. The backpressure from the fluid level was converted to percent full. Clearly an empty tank had zero backpressure and a full one 100%. The beauty of this system was that the sensor never clogged, air bubbled out of the tube in the tank so the sensors were self cleaning. I’ve never seen this system in an RV but it was much better than the often clogged and useless sensors used in RV’s.


October 22, 2020at8:08 am, Jim said:

Hello Mike
You missed one fixer upper. The Wand. I use a wand when I do the last dump after our 6 months snow riding in AZ. The end swivels so I can wash all the walls of the tank and also pressure wash everything down the tube.
We also bought an electronic Sensor system that attaches to the outside of the water/grey/black tanks and wiring to battery and propane tanks. It shows the exact levels in percentage of full.
Works just like a carpenters stud finder. Wires connect to existing wiring so no need to snake wires through coach.

Great blog, great site.
Ontario, Canada
36 ft Damon Daybreak V10


October 23, 2020at3:05 pm, Scott said:

Where did you find exterior sensors. Brand ? Dealer ?


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