You Need To Perform an RV Holding Tank Flush

October 07, 2020

You Need To Perform an RV Holding Tank Flush. Unique Camping + Marine

Key Points:

  • Rinse/flush your wastewater holding tanks for 20-30 minutes every 3-5 dumps.
  • Perform a short rinse every time you dump.
  • Without regular rinsing, sensors could misread, waste can accumulate in low points of the tank, and odors can become a major problem.

Do you rinse your mouth after you brush your teeth? Do you rinse your feet after frolicking on the beach? Do you rinse your dog after he rolls in the mud? Of course, and we do this because we don’t want food particles causing bad breath, or sand to dirty our cars, or our dog to spread its muddy fashion statement all over the house. A rinse of your RV holding tanks is even more important. Odors and clogs do not happen overnight; they can build over an extended period of time of not rinsing your black tank and sneak up on you in the middle of a trip without warning. The great thing is that regular flushing of your black tank(s) can nip this issue in the behind quickly.

This guide will show you exactly why regularly flushing your tank is so important and can help you avoid clogs and odors.


How Often Should I Flush/Rinse My Holding Tanks?

Flushing your RV holding tanks regularly is important, and when we say regularly, we mean every 3-5 dumps. And you should be running your rinsing tool for 20-30 minutes at a time. Rinsing for this long ensures that the water reaches as much of the residual waste as possible that is hanging around on the black tank walls or floor. We also recommend doing a short rinse after every dump, but it is most important to be consistently flushing for 20-30 minutes every 3-5 dumps.


What Type of Tool Should I Use to Perform an RV Holding Tank Flush?

Many RVs have a built-in rinsing system that is attached to the ceiling or side of the tank. Rinsers like these usually spin and spray to rinse waste away down the sides of the tank to the discharge port, but it’s not a bad idea to also have a rinser wand. A rinser wand can be moved around so that all the nooks and crannies in the tank are sprayed as well, something built-in rinsers may not be able to reach. A back flusher is also a great idea because it applies more pressure with the water, which will help loosen any waste clinging to the tank walls. If your RV does not come with a built-in rinser system, you need to get either a rinser wand or a back flusher so you can keep your black tank rinsed and free of residue.

We recommend that you keep your black valve open while rinsing your tank. Keeping it closed could lead to flooding in your RV if you get caught up with something else and forget about it. Regular rinsing is one of the recommendations of The Unique Method and will always be worth the extra time.


Why Should I Flush/Rinse My Black Tank Regularly?

This question is easily answered with a comparison: when using your kitchen sink to wash dishes, food particles sometimes don’t rinse down the sink immediately. They cling to the edges of the walls or the curves in the bottom and you often need to target them with a rinse to prevent them from sticking to the sink walls and having to scrub them off later. The same holds true for your RV holding tank. As even the most liquefied waste slowly drains out, the residue from this waste can cling to the walls of the tank as the levels decrease. Without rinsing, this thin layer of waste remains on the walls and floor to dry until the next use. Every time you dump without rinsing, it adds to the potential for clogs and odors.

In the subsections below, we will discuss some of the problems you can avoid by performing a regular holding tank rinse/flush.


Residual Waste Can Cover Your Sensors

Using a high-quality bacteria and enzyme treatment in your black water tank will help keep sensors clean and free of debris, but the sink analogy above still applies to liquefied waste. As the water level decreases, a thin film of waste can still cover sensors enough to cause them to misread. Without rinsing this thin film off, it can begin to layer and the sensors can start misreading very soon. You want to avoid letting this thin film of waste sit on the sensors for days or weeks at a time to dry, which is why we recommend short rinses on every dump in addition to long rinses (20-30 minutes) every 3-5 dumps.


Waste Can Hide in Crevices and Low Points in the Tank

We always recommend a high-quality bacteria and enzyme tank treatment (like Unique RV Digest-It), but the fact is, no matter how well your bacterial tank treatment digests waste, there will always be some residual waste that accumulates in the crevices or low spots of your holding tank. Not all holding tanks are a perfect rectangle or square. RV designers try to utilize as much of the space as they can for storage and other things, one of which might be storing waste. There can be some pretty oddly shaped holding tanks out there, which can have corners and other crevices that are really good at trapping waste. Refer to our guide on RV Holding Tank Shapes - Could Yours Cause Waste Buildup

Some may argue that this isn’t an issue if you park your RV perfectly level, but there are several reasons why this argument doesn’t really hold up:

  • Parking an RV perfectly level is extremely difficult
  • Many holding tanks aren’t even installed perfectly level
  • Most RV holding tanks are flat on the bottom, so gravity will not be able to move waste out of low points in the tank, which could be present from the RV not being level, the tank not being installed level, or the tank being oddly shaped.

The reality is that despite your best efforts, you will likely still have some waste residue accumulate at low points inside your RV holding tank if you don’t rinse it out regularly.


Odors Can Slowly Become Worse Over Time

You may not notice any odors the first several times you skip the rinsing regimen, but after many days or weeks of waste sitting in low points or crevices in the tank, it can start smelling really bad. And every time you use the tanks after not rinsing, you hydrate the dried out waste in those low points and new waste will start clinging to the crusted waste. Before you know it, you have odors rising and the makings of a compacted tank. 

Avoid all these issues by performing a short rinse every time you dump and a nice long rinse every 3-5 dumps.




Adopt The Unique Method

You bought your RV so you could enjoy life and spend time with family and friends. The last thing you want to do is waste precious time and money on fixing wastewater holding tank problems. Keeping your tanks in peak operating condition doesn’t have to be hard, confusing, or expensive if you follow our proven process: The Unique Method.

The Unique Method is a comprehensive tank care plan that we developed after years of conversations with real customers facing real problems. The Unique Method provides you with simple, preventative steps to stop odors, clogs, and sensor problems before they start so you can spend less time worrying about your holding tanks and more time enjoying the freedom and adventure of RVing. Try it yourself and see why thousands of campers trust their RVs with The Unique Method every day.

If you need more help with anything covered in this guide or simply have a comment, we’re here to help you anytime!

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