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RV Black Tank Flush System: How To Clean An RV Toilet Tank

(Camp Addict does NOT accept payment from any company to review or endorse their products.)

Kelly Headshot

By Kelly Beasley

Last Updated: August 15, 2022

Dealing with holding tanks is the messier side of camping, but learning how to properly drain and flush the plumbing system will help ease any anxiety you have when getting rid of wastewater.

An RV black tank flush system helps ensure that the RV black water tank remains clean and free from the residue from storing human waste. Um, yeah, great picture, right?

In this article, you will learn how to master the art of RV waste tank cleaning to maintain the health of your camper septic system.

Family sitting in chairs in front of Class C motorhome

What Is A Black Tank Flush System?

A black tank flush system is any device made to rinse out the inside of your toilet holding tank.

There are two kinds of RV black water tank cleaning systems:

  • A permanently mounted system consisting of a water supply inlet where you connect a garden hose and one or more spray nozzles that 'flush' the tank walls to help remove all human waste residue so it won't remain in the tank
  • A portable RV tank flush kit that connects to your rig's primary sewer connection (where you attach the sewer hose when dumping your tanks) or a wand that you hold with your hands and insert into the black tank through the toilet. Either portable tank rinsing system requires you to attach a garden hose to it for a freshwater supply.
Tornado tank flush

Whether a portable or a fixed RV black water tank sprayer is used, you have to connect a garden hose to supply water pressure that is shot through one or more spray nozzles to rinse down the tank and remove loose bits of waste.

How Does A Black Tank Flush Work?

A black tank flush works by spraying fresh water into the tank, cleaning off any loose debris from the tank walls.

Some recreational vehicles come from the factory with a black water tank flush system installed, while others require you to use a manual system.

Either way, you need to connect a garden hose that supplies water pressure to clean the RV black tank.

Why Does The RV Black Tank Need To Be Flushed?

Your black tank does not necessarily NEED to be flushed.

Popular thinking claims that flushing will clean out anything stuck to the walls of your black tank. Some styles of flushing tank rinsers will help, and other RV holding tank rinsers will not.

I have never done an RV blackwater tank flush on my travel trailer. Even so, I've never had an issue in my six years.

Camp Addict co-founder Marshall flushes his black tank almost every time he dumps. His RV has a built-in black water tank flush kit, so it's effortless to do so, whereas mine doesn't, making it more difficult.

Recreational vehicle owners that flush regularly very well may prevent toilet paper from causing the RV holding tank level sensors to misread.

It might also help prevent struvites from forming on the sensors and tank walls, also causing sensors to misread.

Trixie dog lying down in front of Kelly's RV outside of Glacier

How Do You Flush A Black Water Tank?

Flushing a black water tank is a straightforward process. It involves only a few steps:

  1. Connect your RV sewer hose, open your black tank valve, and dump your sewage waste into a dump station.
  2. Connect the water hose to the flush inlet or to the flush device.
  3. Turn on the water and let the RV flushing mechanism do its thing for a minute or two.
  4. Be careful not to overfill the black tank. It will back up into your RV if you do! This is why it is advised to keep your black tank valve open while flushing.
  5. Keep it going until the drain water runs clear (though a video we show down below proves that water running clear doesn't necessarily mean your tank is truly empty/clean).
  6. Shut off the water supply and allow all water to drain.
  7. Close your black tank valve, remove the sewer hose, and you're done with the dumping process and RV holding tank cleaning.

How Long Should You Flush Your Black Tank?

You should flush your black tank long enough to see clear water draining from the RV's sewer outlet.

Buy an attachment if you don't have a clear connector somewhere on your sewer hose or between it and the RV. This allows you to observe water flow while you perform an RV sewer flush.

Generally, this RV black water flush should take a few minutes to complete the job.

How Often Should You Flush Your Black Tank?

There is no right or wrong answer regarding how often you should flush your black water tank.

Some people flush their black tank every time they hit a dump station. This is how Camp Addict co-founder Marshall does it, using the built-in RV black water tank flush system on his travel trailer.

Others do the black water tank cleaning every few dumps. Some people (like me) never perform a black water tank flush on their RV. It depends on your comfort zone.

A black tank flush dislodges any toilet paper or other debris that might be stuck to the wall or one of your tank sensors.

Can You Add A Black Tank Flush System?

You can add a black tank flush system if your RV doesn't have one built-in.

There are a few different types of RV black tank flush kits to choose from.

There is a handheld RV tank wand available from Camco that is made to be stuck down into the toilet.

Connected to a water hose, it sprays water all around the tank.

Another option is to get a black water tank cleaner attachment to your sewer outlet. This attachment has a hose connector that you connect a garden hose to.

It shoots water up into the tank, supposedly cleaning it all out. (Spoiler Alert: This style doesn't do anything, and this attachment generally doesn't result in a clean RV black tank. See video below.)

A third option is a permanently mounted tank rinser that requires drilling through your tank. This is a viable option if you have access to your black water holding tank and are comfortable drilling through it.

The Camco Tornado is an example of an aftermarket, permanently installed flush kit.

What Is The Best Black Water Flush Kit?

There are only a few good mechanically effective black water flush kits on the market. Here are a few popular ones:

Tornado Rotary Tank Rinser: This permanently installs INSIDE your black tank. Once installed, you connect a water supply and let 'er rip! The Tornado black tank flush slings water all around, likely removing any debris or dookie bits off of the walls. It helps finish draining stuff from the bottom as well. Watch this video by The Fit RV for proof (below). We could not do a better review than theirs. Watch for yourself to see what we mean. Jump to about 18:25 for the Tornado tank rinser test.

Tornado tank flush

Tornado Tank Rinser

Camco Swivel Stik: This gem of an RV black tank flush kit allows you to reach everywhere inside the black tank. We believe this is the most effective way to get all debris off of the walls of your black tank. To get the most coverage, you can lower and raise this RV black water tank cleaning wand. This is something NONE of the other products accomplish. Plain logic says that a Camco tank rinser is the most effective product of them all as it gives you the most control, though it is not nearly as convenient to use as a permanently mounted tank rinser.

Please note that to use an RV black tank flush wand, your toilet must be mounted directly above the black tank so that the rod has a straight shot to access the tank. If your waste tank is mounted away from the toilet, there will be plumbing pipes between you and the tank, which the Camco tank rinser won't be long enough to reach past.

Camco swivel stick

Camco Swivel Stick

Camco Rhino Blaster: Welp, in the video above, it is proven that this RV holding tank rinser style doesn't work well. This RV black tank cleaning product (and any similar ones) is a waste of money, and don't bother buying one. This proof is also in the above video. Still, if you MUST buy this type of RV tank rinser, here's a link below.

Camco Rhino Blaster Pro

Rhino Blaster

How Do You Use A Black Tank Wand?

Using a black tank wand is very easy! An RV black tank cleaning wand is made to stick down into the toilet hole with a water hose attached to it.

Connect the water hose, run it into the camper, down the toilet, and turn on the water. The RV tank cleaning wand acts like a sprinkler for your black tank.

Swivel stik in action

Let it slosh around at the bottom, then slowly move it up while letting the wand do its job.

Finally, once the water runs out into the dump station clear, you're done.

Turn the water off and remove the wand. Easy-peasy!

We like the Camco Swivel Stik.

What Can I Use To Clean My RV Black Water Tank?

There are a couple of different RV black water tank cleaner options depending on what you are trying to accomplish.

If you are looking for a true RV black tank cleaning solution because an obstruction needs to be removed, you need a powerful RV septic tank cleaner such as Unique's Holding Tank Cleaner.

This cleaner is more potent than almost every other RV black water tank treatment and is formulated to unclog waste tanks in 12 to 72 hours, with no driving around necessary.

Unique tank cleaner

If you are looking for an RV holding tank maintenance solution that keeps odors down, there are a couple of great choices.

The top powder camper holding tank cleaner is Happy Camper black tank treatment. We have used this enzyme in the past very successfully to curb odors and to break down waste.

Happy Camper toilet treatment

Not Available In California

If you want to stop struvites from forming, use TankTechRX, which is a liquid RV waste tank cleaner. But you must start with a clean RV holding tank (have it professionally pressure washed to eliminate any mineral or struvite buildup) for this product to work correctly, keeping your sensors working.

Kelly's View/Belief That Tank Treatments Are Unnecessary

Having a black water tank clogged will never be an issue if you do just a few simple things and do them right.

Personally, in my six years of full-time RVing, I never performed a black tank flush. I also stopped using any treatment products probably five years ago.

(Camp Addict co-founder Marshall does flush his black tank and does use a tank treatment, so to each their own!)

Also, the black tank sensors stopped working right from the start, but I have zero need for them to work.

Why? I know approximately how long I can go before needing to dump.

I've also never subscribed to the 'use a lot of water when you go #2' theory. Even so, zero problems. (Because I don't flush my toilet paper!) I use just enough water to flush without going overboard with freshwater usage.

If I'm mistaken or don't keep track, my toilet will burp and let me know when I only have a few flushes left and should dump my black tank.

Waste Master hose coiled on grass

Do these things, and you won't need an RV black water tank treatment:

  1. DON'T flush your toilet paper. It can cause clogs and makes you have to dump sooner than later as it takes up a lot of space in the holding tank.
  2. Make sure your black tank is almost full before you dump. The volume of the liquids flowing out will remove most of the solids from the tank.
  3. NEVER leave the black water tank dump valve handle open while connected to the sewer at a campsite. You will end up with the dreaded 'poop pyramid' clog if you leave your tank valve open.
  4. Use plenty of water when you flush your RV waste tank. You'll want to use enough water to have more water than solids in the tank, but you don't want to use so much that you prematurely fill the waste tank.
  5. If you choose to flush your TP, use ONLY septic-safe brands and go ahead and rip up what you break off before you use it. Try not to use a huge amount of toilet paper, either. (Is RV toilet paper necessary?)
  6. ALWAYS entirely dump your black RV tank before you store your camper. This method avoids a solid mass of poo at the bottom after all the liquids evaporate.
  7. Odor problems: You may want to use an RV black tank cleaner if you are having odor problems (such as your RV toilet smells when flushed). If you can smell it, it's probably hot outside. Heat causes the smell to get worse. There are RV black tank cleaning products on the market that help stop the smell.

Conclusion

You have a couple of options regarding how to flush RV tanks. Some styles of black tank flush kits work well, and others don't do so great when it comes to cleaning an RV black tank.

Flush methods vary, and we only recommend ones built into your RV or the Camco handheld wand.

Dump Station sign

Now you know more about how to clean an RV black tank. There are several different techniques when it comes to RV black tank maintenance.

You need a few items on hand for your waste tanks, a little knowledge of how to use them, and an easy-to-follow process for cleaning an RV black tank.

If you're that person who is in charge of the cleaning method for your tanks, stay on top of it, use some RV black tank flush system, and you should be good as gold!

Kelly Headshot

Hello! I'm the co-founder of Camp Addict, which my biz partner and I launched in 2017. I frigging love the RVing lifestyle but in December of 2020, we both converted to part-time RV life. Heck, I lived in my travel trailer for over 5.5 years, STRICTLY boondocking. I learned a lot about the RV life and lifestyle during those years. Now we share what we know with you here at Camp Addict.

After that many years of wonderful full-time travel, it was time for something new. These days, I'm often found working from my new Az home, and sometimes plotting and scheming whether or not to start collecting farm animals (or plotting my next RV trip!).

  • I never considered that build-up would cause a sensor to misread. Makes so much sense though. Will be sharing this informative post with RV group online.

    • Yeah, I just don’t use my indicators on my travel trailer anymore. Now I have a new van… and the sensors are on the outside, so no worry about buildup!

  • There is another model of Rhinoblaster that has a shutoff valve on the sewer line, so it should be functionally equivalent the Flush King in the video.

  • I really appreciate this in-depth article, Kelly. I learned a lot. I had not realized that some solutions might require you to drive around to clean a tank effectively. We are buying an RV for our family to travel around this year so I am thankful to have read these tips and for the added what NOT to-do list.

    • Hi Betsy,
      Biggest NOT to do is put your TP down the hatch! It’s seriously one of my favorite RVing hacks. Saves tank space and avoids almost 100% of clogs! Glad you found us, and good luck with your future adventures! How exciting!

  • Just when I thought I knew everything there was to know about black tanks, I learned that I didn’t know about struvites.

    • LOL! Yeah, they are a thing! In every septic system that exists! NOW you see why it’s so hard to keep tank sensors working!

  • We used the Rhino Blaster on 10 RV rentals with great results on all but one. The one had a different bend in the outlet pipe.

  • Great content here, thanks for sharing your knowledge. My wife and I are in process of finding and buying our first RV, so simple yet comprehensive tutorials like this are excellent to prepare us for realities we will face. Much appreciated Kelly!

    • Hey Dennis!

      Well, we LOVE to hear this type of feedback! We so appreciate you taking the time out of your day to let us know! How exciting to be getting your first RV! We have an excellent buying guide about best brands here:

      https://campaddict.com/best-rv-brands/

      That may not be what you are going for, but the better of a brand you start with, the less likely you are to have issues with it.

      We also have a page on buying RVs here:

      https://campaddict.com/buying-rv/

      Best of luck to you two and thanks for checking out Camp Addict!

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