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How to Prevent RV Blackwater Tank Problems

Published on December 15th, 2022 by Rene Agredano
This post was updated on January 12th, 2023

Do you use your RV toilet when you camp? I’ve discovered that many RVers don’t use their on-board latrine in order to prevent RV blackwater tank problems. When nature calls, they use campground bathrooms instead.

If only the knew they have nothing to fear. Most RV toilet problems can be prevented by paying attention to what goes into the tank. And also, how you maintain the tank when you’re using it.

Follow these blackwater holding tank tips to find out how to prevent clogged RV toilets, and the dreaded “poop pyramid.”

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Here’s How You Can Prevent RV Blackwater Tank Problems

In my 15 years of full-time RVing, I’ve never had a single RV blackwater tank clog or problem in my own. There are so many ways RVers can prevent plumbing system problems, there’s practically zero reason to have them in the first place. Let’s review some of these common-sense RV blackwater tank tips.

Is it Really OK to Poop in RV Toilets?

poop emoji
Don’t be afraid of your RV toilet!

Many RVers refuse to use their camper toilet. “It just causes so many problems!” one RVer friend recently said to me. He worries that using the RV toilet will result in plumbing clogs, smells, and blackwater tank issues. So he and and his entire family use campground restrooms instead of enjoying the convenience of having their own restroom. That’s too bad. Avoiding RV toilet and blackwater tank problems is easy, and comes down to three things:

  1. Only use single-ply, septic-safe toilet paper.
  2. Never flush anything other than human waste, TP, water, and RV holding tank treatments.
  3. Rinse your blackwater tank each time you dump.

Let’s review how each of these points can help you prevent RV toilet clogs, holding tank, and plumbing problems.

Only Use Single-Ply, Septic Safe RV Toilet Paper

One of the first things many new RVers buy before they ever leave the RV dealer is that expensive dissolving RV toilet paper. I know I did! This pricey paper is marketed to boaters and RV owners who worry about RV blackwater tank problems. They buy it, even though it’s not the softest or strongest TP around. This TP sells because unknowing RVers assume it’s the only way to go.

If you’re thinking that RV TP is not a scam, it’s not. The product does what it’s supposed to do: rapidly disintegrate once it falls into your RV blackwater tank. By doing so, it minimizes the chance of RV plumbing clogs and blackwater tank problems.

But is RV toilet paper worth it? Can other less expensive toilet paper brands not made for RVs do the same thing? Let’s take a look:

As you can see from the video, even generic Walmart single-ply toilet paper dissolves exactly the same as expensive RV toilet paper. In my experience, any single-ply toilet paper marketed as “septic-safe” will also quickly dissolve. Ever since I did my non-scientific RV toilet paper test, I stopped spending extra money on RV toilet paper and bought single-ply brands at our local grocery instead . You’ll usually find Scott brand in our RV bathroom storage cabinet, since Walmart single-ply can be hard to find.

Never flush anything except human waste, TP, water, and RV holding tank treatments.

Many RVers who boondock frequently say they fill up their gray water tank first. To get more time out of it, they dump kitchen waste graywater into the blackwater tank. Some even install an RV graywater recycling system to conserve holding tank space.

I can’t vouch for how well those systems work. But I do know that if you’re going to flush anything other than human waste, TP, water, or RV holding tank treatments into your blackwater tank, you’re asking for trouble.

RV Blackwater Tanks are NOT Septic Tanks

Your blackwater holding tank was designed for one purpose: to contain human waste until you flush and dump the entire tank contents at a dump station or full-hookup campsite.

It is not like a residential septic tank either, which gradually breaks down solid waste into liquid sludge. Under normal use, RV blackwater tank contents usually do not sit long enough to decompose the same way it does in a septic tank. The RV chemicals you buy (or the Geo Method DIY holding tank treatment recipe you make) simply make waste less smelly, and easier to rinse out of the tank.

Odd smells and even tiny flying bugs are some of the well-known side effects of putting unconventional waste into your RV toilet holding tank and allowing it to sit. Just don’t do it.

More Ways to Avoid RV Blackwater Tank Smells

Some of the best ways to avoid smelly RV blackwater tank problems is to:

  1. Use plenty of water when you flush (especially after pooping). By flushing at least five seconds of clean water into your RV blackwater tank, you can prevent the dreaded “Poop Pyramid.” This heap of stinky waste pile happens when your tank doesn’t have enough water inside to move it around, and finally out, of your tank when you dump.
  2. Put a few gallons of water into your tank after dumping. Generally, that means putting about 3-4 full bowls of clean water into the tank. This helps you avoid the RV toilet poop pyramid described above.
  3. Keep your black tank valve closed when you’re not dumping. Do not ever leave your RV blackwater tank valve open at the campsite. You’ll drain your tank of water, which pushes stink out of the tank and directly into your RV. Not enough water also causes poop to stick to one spot and create that poop pyramid.

Rinse Your RV Blackwater Tank Every Other Dump

Most RVs now come with a blackwater tank flush system. Rinsing our tank regularly is probably the biggest reason why we just don’t have RV blackwater tank problems. The flush system hose attachment on the outside of my RV allows me to connect a graywater (not a drinking water) hose and aim a steady blast of rinse water directly into the blackwater tank.

Rinse your RV blackwater tank for several minutes to give it a good flushing. The best way to know your tank is clear is to get a clear RV sewer hose connector.

clear RV sewer hose connector
A clear sewer hose connector shows when your blackwater tank is cleaned out.

When you see clean water going through it and into the sewer drain, you’re done!

No Blackwater Tank Flush System? No Problem!

If your trailer is older and you don’t have a blackwater tank flush system, you can buy a flexible tank wand instead. This device blasts rinse water directly into your RV toilet and down your black tank. If you travel with a partner, have them watch the clear connector to check for clean water running through it.

Bonus Tip: It’s Good Etiquette to Make a “Sign of the Cross” When You Poop in RV Toilets

If your RV toilet bowl is plastic, you probably noticed that poop often sticks to the sides. There is a way to avoid this mess. First, add a tiny bit of water to wet the bowl sides. Next, layer two strips of toilet paper into the bowl before using it. Once you go, waste sticks to the paper instead of the bowl!

RV toilet paper to prevent poop stick
Layer single-ply toilet paper into a cross to prevent poop from sticking to the bowl.


RV toilets are meant to be used. It’s simple to prevent RV toilet and holding tank problems. Keep your RV toilet bowl clean, be good to your RV blackwater tank by adding plenty of water when you flush and dump, and don’t flush anything that wasn’t meant to be in there. Be good to it and you’ll be glad you don’t have to use public campground restrooms ever again.

This post may contain affiliate links or mention our own products, please check out our disclosure policy here.

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