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Preventing Clogs In Your RV Holding Tank

February 24, 2020

Avoiding and preventing clogs and backups inside my camper RV motorhome trailer fifth wheel black water toilet holding tank

Key Points

  • RV Toilet clogs are easy to avoid if you employ the right practices
  • Proper use of water, a high-quality holding tank product, and basic maintenance changes will ensure you never deal with RV holding tank clogs ever again. 

Clogged and foul smelling RV holding tanks and toilets are one of the leading issues RVers deal with every single year. These clogs and odors are frustrating and have the potential to turn travelers away from the RV lifestyle. The good news is that it is possible to have clog and odor-free toilets, and believe it or not, preventing these issues is really simple. In this guide we are going to explore how to prevent clogs and odors in your RV black water holding tank.  

Keep Your Black Tank Valve Closed Unless Dumping

One of the biggest pieces of misinformation in the RV world is in regard to the black tank. Many out there recommend that you keep your black tank valve open whenever you’re hooked up, but believe it or not, this practice is easily one of the main causes of clogged or backed-up black water holding tanks.

When you leave your black tank valve open, any liquid inside your holding tank drains out and all that you're left with is the solid waste. While it was in your tank, that liquid was helping to break down the waste and cover the odors. Without the liquid inside the tank,  something called a pyramid plug can form. A  pyramid plug is literally a pile of waste that has accumulated inside your tank! Many people don't realize that their black water holding tank is most likely flat across the bottom. This means that if there isn't a large amount of water for your waste and toilet paper to fall into, it simply lands on the bottom of the tank, eventually building up into a pyramid.

Avoid a clogged holding tank by preventing with the right product and process. Unique Camping + Marine

A Note Of Caution To The Lucky Ones

You might be one of those campers who always leaves your black tank valve open and you've never experienced any problems. First, you're lucky! Second, our experience helping hundreds of frustrated RVers deal with clogs tells us that you're sitting on a ticking time bomb! It's probably only a matter of when, not if, you finally experience a clog, pyramid plug, or back-up. We strongly recommend that you change this practice while you're still ahead!

Use A High-Quality Tank Treatment

One of the most important steps you can take to avoid clogs and backups in your RV black water holding tank is to regularly use a high-quality holding tank treatment.  We recommend choosing a bacteria-based tank treatment. Bacterial-based products work amazingly well and  leave no byproducts behind that might potentially cause a clog in the future. There are other holding tank treatment types available, but again, we highly recommend you take the bacterial route simply because it is so effective at keeping your tanks clean and fresh-smelling. 

Guide Continued Below

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Use Plenty Of Water

Believe it or not, using plenty of water is one of the most crucial steps you can take toward keeping your system free from clogs and odors. It is crucial that you hold the flusher down for at least 10 seconds every time you use the toilet. This allows plenty of water into your holding tank. This water prevents pyramid plugs from forming, and creates an odor barrier, so long as the water level is above the waste in the tank. It also helps to nourish the bacteria from your high quality tank treatment, helping them work their hardest to break down waste and odors even more. 

Avoid Bleach-Based Or Chemical Cleaners

Never use any bleach-based or chemical toilet bowl cleaners. These products will kill the beneficial, waste-digesting bacteria inside your tank. This bacteria is introduced through your bacterial tank treatment product, but also comes naturally from the materials and waste inside your tank. If you damage or kill this bacteria by using chemical cleaners, it can easily lead to clogs as well as damage your toilet’s seals and valves.

Keep Temperatures Regulated

All high-quality bacteria based holding tank products have an effective temperature range of roughly 45° F to 85° F. On either extreme end of that spectrum, all brands of bacteria-based holding tank treatments will struggle. If you’re camping in either of these environments, we recommend insulating or heating your tank in cold weather and increasing water usage + higher dosage of bacteria treatments in hot weather.

Flush Your Tank

Every time you dump your tank, flush or rinse it well. The longer you rinse your tank, the better. This will help to clean out the nooks and crannies of the tank (we recommend 20-30 minutes of rinsing when possible). This thorough cleaning will ensure that no residual debris is hiding somewhere in the tank waiting to create a future clog. 


As you can see, preventing clogs is actually pretty easy and painless. With a few simple adjustments to your holding tank habits, you can ensure a clog free RV in no time! Do keep in mind that information in this guide fits into the bigger picture of overall holding tank care and maintenance and is part of a step by step guide we call The Unique Method. To learn how to maintain both your gray and black tanks and get the most out of your RV travels we recommend you use The Unique Method. We hope this guide has helped answer your tank clog questions! Feel free to contact us if you need help. We’re always happy to help. Happy camping!

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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