Picture this: You’re in the middle of the RV trip of a lifetime. You’ve just set up camp. The sun is shining, temps are starting to rise, and everyone in the family is smiling. But soon you begin to notice a smell. It lingers in the air of your RV and turns up the noses of your fellow campers. Soon, you discover the source: the smell of poop inside your holding tank is seeping up into your RV! Maybe you're new to RVing, and you try to fix the problem using recommendations from other campers, but nothing you do seems to help. Then the temps hit 90 degrees Fahrenheit as the sun reaches its zenith in the sky, and the smell becomes almost overwhelming. You quickly start wondering if this is what RVing smells like! Are these smells normal? Can they ever go away? Did I make a mistake buying an RV?!
If you’ve experienced this situation or one like it, we’re here to tell you that you’re not alone! The truth is that nothing can ruin an RV trip like seemingly uncontrollable, nasty odors coming from your holding tanks or toilet.
Many RVers—even seasoned pros!—have experienced similar situations. Sure, there are many chemical products that can artificially mask those nasty odors, but these products aren’t getting to the core of the problem. Moreover, these products can be dangerous and damaging to you, the environment, and even your RV.
There are many “solutions” offered by fellow campers, online forums, RV service technicians, and websites that claim they will help you eliminate tough toilet odors, but we know from talking to thousands of RVers, just like you, that these solutions leave most RVers still struggling with smells.
Don’t worry. There are actually are proven ways you can eliminate these odors and we’ll go through them one by one with you. The fact is, you don’t have to live with odors in your RV.
We literally talk to hundreds of people every month with these problems and we’re happy to tell you that there are workable, easy solutions that will tackle toilet odors at their core so you can forget about your RV holding tanks and enjoy your RV!
Before we get to the solutions, however, let’s examine exactly why your toilet and tanks stink.
Inside your holding tanks, there are two basic types of bacteria: aerobic and anaerobic. These two types of bacteria function in different ways. Aerobic bacteria (which we’ll call “good” bacteria) thrive in oxygen-rich environments, emitting only carbon dioxide and water as they break down human waste and toilet paper. Anaerobic bacteria (we’ll call them “bad” bacteria), on the other hand, release smelly hydrogen sulfide gas as they break down waste. Anaerobic bacteria are found in your stomach, and when you use the bathroom in your RV, those anaerobic bacteria get released into your holding tank, where they can produce disgusting odors! Check out this article for more on anaerobic and aerobic bacteria.
We need to be clear about something here: both types of bacteria will break down solid waste inside the tank, which is a crucial step in avoiding clogs and backups. Only one, aerobic bacteria, can do this without creating smelly byproducts and odors. Remember, bacteria is absolutely necessary inside your tank. Just make sure it's the RIGHT kind of bacteria.
As hinted above, odors can get even worse in hot weather. As a matter of fact, hot weather is the perfect breeding ground for awful sewage odors. There are two main reasons why hot weather makes smells worse in your RV:
Now that you know why sewage odors occur in your toilet and holding tanks, let’s get back to what you can do to fix it.
First off, you need bacteria in your holding tanks! In fact, at the root of your odor problem is probably a lack of good bacteria. For one thing, bacteria are crucial to breaking down the poop and toilet paper in your tanks. Without bacteria, you will experience clogs and backups, because the waste will not be liquefied. For another thing, you will not completely eliminate your odor issues without good bacteria. Once you solve the problem of having enough of the right bacteria in your tank, you can start to tackle other issues one-by-one, but before you do anything else, you must understand that good bacteria are necessary.
Now that you understand how important it is to have a flourishing colony of good, aerobic bacteria in your tanks, we want to stress how important it is that you support the flourishing bacteria with proper treatment process. A good treatment product is only as good as the treatment process you are following. We have created a guide that will help you perfect your processes so you can maximize the effectiveness of the treatments you are using. Learn more about The Unique Method here.
Now, we'll discuss why other types of treatments don't fully get the job done.
Unfortunately, the common “traditional” advice RVers receive is to use a chemical treatment in their tanks. But there are many reasons you should not do this!
First, some treatments simply mask poop smells with strong fragrances that are often worse than the poop smell! In other words, these treatments add no bacteria to the tank, and they only mask odors with strong fragrances. They do nothing to fix the issue at its core.
Second, other caustic chemical treatments (for example, those containing formaldehyde and bronopol) will actually kill bacteria. There are even some quote-on-quote “natural” treatments out there that will kill bacteria. Some of these bacteria-killing chemicals will also mask smells with strong fragrances. These chemical treatments not only fail to fix the problem, they can actually make it worse. Remember, you need bacteria in your tank, and these chemical treatments don’t just kill the “bad” anaerobic bacteria. They kill all bacteria, both good and bad! So if the goal is to add good aerobic bacteria to your tank, you’re defeating the purpose by using a caustic chemical treatment.
So in the end, the best option is to force bad anaerobic bacteria out of the tank by replacing them with good aerobic bacteria. You don’t need a caustic chemical treatment with this approach. All you need is a powerful, safe product (like Unique RV Digest-It) that contains high-quality aerobic bacteria and lots of water. By using this sort of product with lots of water, you will effectively push out the “bad,” odor-creating anaerobic bacteria and replace them with “good,” odorless aerobic bacteria. Using a lot of water allows these good bacteria to thrive, and like we said above, aerobic bacteria do not release smelly byproducts as they break down waste. Instead, they release only carbon dioxide and water.
In other words, if you treat your tank with aerobic bacteria, you will get highly effective waste breakdown and keep your tank odor-free! It’s honestly the best of both worlds.
Now that you know that having good aerobic bacteria in your holding tank and following The Unique Method is the crucial first step to eliminating odors, we can cover some of the other common problems people have with tank odors. Because the fact is, even if you are treating your tank with a good bacteria treatment, it’s possible that you might still experience other issues.
With this in mind, we’ve compiled a list of some common odor problems RVers often experience and our recommendations for solving these problems. Please keep in mind, these problems can oftentimes be persistent and in some cases seem unsolvable; however, we promise that if you keep working toward a solution with our help, together in most cases we’ll be able to fix your problem! If you are dealing with an especially persistent problem related to toilet and holding tank odor, please feel free to reach out to our customer support team.
Solution: Make sure the water inside your holding tank is completely covering your poop! If you’ve ever used a Porta Potty (which, let’s be honest, most of us have) then you know what we’re talking about. A Porta Potty where the poop is above the waterline stinks to high heaven, but one that has water covering the poop doesn’t smell so bad. The reason is that the water acts as a barrier to the sewage odor, and the same thing applies to your holding tank. TIP: You don’t need to keep water in JUST your holding tank. This also applies to filling your toilet bowl with water every time you use it and leaving a few inches of water in your toilet bowl at all times. It adds yet another barrier blocking the sewage odors from entering your RV. You can add water to your toilet bowl by either partially holding down your flush pedal until the bowl fills or choosing the “fill” option on your toilet if your RV comes equipped with this feature. In general, by using ample amounts of water in your holding tank, you’re ensuring that all your poop is completely covered. Check out The Unique Method, which relies on using lots of water!
Solution: Properly using a product containing good, aerobic bacteria—like RV Digest-It—in conjunction with ample amounts of water to push out the bad, anaerobic bacteria. Too many anaerobes coupled with too little water means a lot of disgusting sewage odor. If you don’t regularly treat your tank with a high quality aerobic product like RV Digest-It (and enable it to work by keeping it sufficiently cool and hydrated with plenty of fresh water) you’re effectively “treating” your tank with anaerobic bacteria every time you use the toilet! By pushing out excessive anaerobic bacteria and replacing it with aerobic bacteria, you’ll still be able to break down waste, but you won’t have to deal with the smell! Also, using plenty of water allows the aerobic bacteria to thrive and completely break down the waste inside your tank.
Solution: Because excessive temperatures can cause water to evaporate from your toilet and/or your holding tanks, it becomes doubly important to use plenty of water. High heat will lead to exposing your poop above the water line. In all honesty, you can’t use too much water (until you need to dump the tanks, of course). The more water you use, the less odors you will experience!
Solution: Use more water! It might seem redundant at this point, but using more water in your holding tanks will help to facilitate the breakdown of waste by helping the aerobic bacteria to thrive by cooling down the tanks (creating a more hospitable environment for the good bacteria) and hydrating them (they are living organisms that require food and water to survive). Hot weather can also increase odors, as we’ve seen, and the more water you use, the cooler your tanks will be and the less odors will be an issue. In essence, more water means less odor issues.
Solution: As we’ve covered throughout this guide, you should be using a high-quality, bacteria-based product that will replace smelly anaerobic bacteria with odorless aerobic bacteria. Many chemical treatments are just meant to mask the issue with heavy perfumes, others are designed to kill bacteria, and many are downright dangerous. Some enzyme treatments can help digest solid waste, but enzymes cannot eliminate odors. Some RVers employ varying homemade remedies that they have heard through the grapevine, yet our conversations with RVers have show us that these homemade treatments promise a lot but deliver very little and should simply be avoided. Only bacteria treatments can do everything necessary in the tanks - break down waste and eliminate odors. All in all, you need a product that uses bacteria to create the right enzymes to break waste into smaller pieces so that the bacteria can completely digest it, thereby removing odors completely. Again, we recommend RV Digest-It.
Solution: Now that you understand how important good bacteria is in your tanks, you should do everything you can to support that bacteria - and not kill it! Not only will that lead to more odors, but you are neutralizing the product you paid to treat your tanks with. Stop using these products! Products like bleach-based toilet bowl cleaners or disinfectants you use to clean your surfaces can wash down your toilet and kill the active bacteria inside your tank. Also, be cognizant of what products you are using in your shower and/or your sinks. Some shower and dish-cleaning products can kill off the good bacteria in your gray tanks (or black tanks if your RV shares one tank for all waste water). You can learn more about what products are okay to put in your holding tanks here.
Solution: If the added perfumes from your treatment are so strong that you’re smelling them inside your RV, your treatment is bad; stop using the treatment! All you are doing is replacing one pungent smell with another.
Solution: Make sure that the wind is blowing odors away from your RV instead of back into it. Sometimes, if you position your RV in the wrong way, the wind will blow odors back into your RV rather than allowing them to disperse into the outside air through vents that are designed to expel pungent toilet odors. For instance, some RVs have the vent on the side, so you will want to make sure that you face the RV away from the wind. For other RVs where the vent is located on the roof, cyclone sewer vents can be attached to the top of the vent pipe. These cyclone vents act like weathervanes, following the wind and creating a vortex that pulls odors up and away from your RV.
Solution: It may seem overly simplistic, but you should make sure that your ventilation system is properly installed. For example, sometimes the hole in the ceiling of your RV where the vent would go was never cut. As a result, none of the odors can escape. Proper inspection and repair of your ventilation system can help to fix this issue.
Solution: Check your system regularly for damage to seals. Your system should be sealed completely from the inside living space of your RV. If you are consistently experiencing persistent odors, you may have some leaks or broken seals. If your system is leaking, it can cause damage to your underbelly or fill your RV with nasty smells. So it’s important to inspect your system regularly. Also, Unique Camping + Marine products help to soften seals, so using them regularly will help to prevent a leaky system. View all of our RV products here.
Solution: Keep your black tank valve closed! If you’re following The Unique Method (which, let’s be honest, you should be!), you’ll know that keeping your black tank valve closed is the cardinal rule! Unless you’re dumping your tank, your black tank valve should always stay closed. Otherwise, all the water will flow out of your tank, and you will be left with an exposed pile of stinking poop that cannot be digested by the bacteria. Besides promoting pyramid plugs, leaving your black tank valve open can allow noxious gasses from the sewer to back up into your RV. Not only are these offensively smelly, but they can also be dangerous as they contain methane.
Solution: Flush your tank regularly - ideally every time you dump your tanks. At the very least, you should be rinsing your tanks every 3-5 dumps. If your RV does not have a built-in rinser wand, you can use a reverse jet flush or tank cleaning wand. It is very important that you flush your tank frequently if you want to get rid of odors. It might seem like leaving a little bit of waste in your tank isn’t a huge issue. But, by way of analogy, if you leave even just a tiny piece of food in your refrigerator for years, it will eventually start to stink just as much as a larger portion would have. The same applies to your holding tank. Even a tiny amount of residual waste can cause just as bad of odors as a large amount, so it is crucial to regularly flush it out.
Solution: Similar to what we just mentioned above, you should perform regular, long rinses on your holding tanks because waste can accumulate because the holding tanks are actually out of level. Many people who live in RVs for extended periods of time will have issues with residual buildup of waste. No matter how level you think your holding tank is, there is almost always a low-point where waste can slowly build up until there is a block of poop stuck inside your tank, which can cause odors. Don’t think your holding tank is unlevel? Think about this: Your RV’s doors are supposed to be perfectly level, right? But we hear from people all the time that their doors won’t stay closed when driving. And here’s the rub: if they can’t install your doors perfectly level, how can you be sure they installed holding tank perfectly level? The point is that your holding tank drains using gravity and it's highly likely that because it was installed slightly out of level - or because you are parked slight out of level - poop can slowly accumulate and lead to odors. Occasional use of a good bacteria-based tank deep-cleaner along with regular, long rinses of your tank should fix this sneaky problem! You can rinse your tanks by using the built-in tank flush system if your RV is equipped with one, using a wand or valve-mounted tank backflusher, or by simply filling your tank with freshwater and dumping the tank several times.
Solution: For full hook-up campers who keep their gray tank valve open, put a p-trap (below) in the line to prevent sewer gas from backing up into your RV and deep clean your gray tanks regularly. We should be clear that if you fail to put a p-trap in your line you will not necessarily smell a sewer or poop odor coming from your gray tank. Instead, many RVers report the smells is more like a pungent garlic. For dry campers and boondockers who leave their gray tank valve closed, odors can back up into your RV from accumulation of waste inside your gray tank. This is due to the residue not only from food-grease, but also from soap, shampoo, conditioner, and even human hair that gets into the tank. To eliminate these odors, treat your gray tank regularly with RV Digest-It and deep clean the tank regularly with Unique Tank Cleaner.
Like we said above, no solution is unfixable, but some can sure seem that way. Persistence in the face of these problems is key, and we’re here with you every step of the way. Remember: Using a high-quality bacteria-based treatment in your tank is the number one solution to tank odors. Without this first step, none of the secondary solutions given above will ultimately work. You must also treat your tanks the proper ways. The Unique Method will teach you how.
This page has given you a host of different causes and solutions for odors in your RV, but if you're looking for a more telescopic view of what causes holding tank odors in your black and gray tanks, please check out this article, which shows you how to deal with odors in a more particular case while also detailing some of the specific underlying causes of holding tank odors.
Again, if you’re having persistent issues, please reach out to customer support for quick help. We talk to literally hundreds of people every month, providing helpful solutions that fully and easily fix holding tank problems. We’d love to help you, too!
If you’re a full-time camper, you understand that staying in your RV year round can have its benefits as well as drawbacks. The full-time RV lifestyle is adventurous and fulfilling, but odors can often become an annoying issue for full timers, not only in your black tank, but in your gray tank as well.
If you’re experiencing disgusting odors while full time camping, we recommend that you clean your tank regularly with Unique Tank Cleaner. This will help to prevent odors before they develop. To treat your tank, first fill it completely with water. Next, add a full bottle of Tank Cleaner to the tank and let sit for a minimum of 72 hours, allowing the product plenty of time to force any unsavory, odor-creating microbes out of the tank.
If for any reason you are unable to fill your tank completely with water, you can choose to fill it half full with water, add Tank Cleaner, and continue regularly using your toilet, ideally letting the product work for at least 72 hours. This method is not your best option, but it can work in a pinch, flushing at least some of the odor-creating microbes out of the tank by removing some waste residue. Just remember, Tank Cleaner only removes smelly microbes if the bacteria within the product physically touch them. Water allows the bacteria to freely travel throughout your tank, so if the tank is only half full of water, the bacteria will not completely remove odors.
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!