Despite what you hear or see on social media, sometimes RV life stinks – literally. You may enter your RV and find that it smells like an outhouse. That can make it impossible to enjoy an adventure. Do you know how to get rid of the smell from an RV’s black tank? If not, today’s article is for you!
Today we’ll show you how to prevent your RV’s black tank from smelling so you can avoid this disastrous situation.
Let’s get started!
What is a black tank for motorhomes?
A black RV tank is a hard plastic holding tank that holds human waste and toilet paper from an RV’s toilet. The fecal matter remains in the tank until the owner can properly dispose of it through a landfill or other sewer connection.
As might be expected, foul odors can result from the contents of these tanks.
The size of these tanks depends primarily on the RV. Smaller motorhomes and travel trailers may have black tanks ranging in size from 15 to 30 gallons.
However, for large motorhomes and massive travel trailers, black tanks of 60 to 100 gallons are not uncommon.
These tanks are usually located directly under the toilets in an RV. If the RV has more than one toilet, there is a good chance that it also has more than one black tank.
It is important to maintain and care for these tanks to prevent odors.
Why does the black tank of my camper smell so bad?
If your black tank stinks, you need to know that you are not the first RV owner to have this happen to you. Even though people don’t always talk about it, it’s not uncommon.
A strong and unpleasant odor coming from your RV’s black tank can have several causes.
One of the most common reasons is the accumulation of waste and bacteria in the tank. Over time, waste can accumulate on the walls and bottom of the tank, creating an ideal environment for bacteria to grow. It doesn’t take long for foul odors to invade your RV.
Another common reason for a smelly black tank is that the tank is not drained properly or cleaned regularly.
Waste begins to decompose when it sits in the black tank, which can lead to a strong and unpleasant odor. You don’t want the waste to stay in your tanks any longer than necessary.
The odors in your RV can also be caused by a faulty sewage system. Venting problems can cause gases to escape from the tank into your home on wheels.
In this case, you can clean your tank as many times as you want, but the odors will return as soon as you refill your tank.
Can I put bleach in my RV’s black water tank?
Although bleach can effectively kill odor-causing bacteria, you should never use it in your black water tank. If you do, you could seriously damage the rubber seals and plastic parts over time.
Also, it is important to know that not all bacteria in your black tank is bad. Some bacteria that grow in the tank are necessary to help break down solids. Using bleach in your black tank can cause the odor to deteriorate.
More importantly, mixing bleach and urine can cause chlorine gas. This gas can cause coughing, watery eyes and a runny nose. Avoid this mistake by never using bleach.
Instead of bleach, we recommend using only products specifically designed for cleaning and maintaining your tanks.
There are a variety of cleaners, deodorizers and enzyme-based treatments that break down waste and eliminate odors without damaging the tank or its components.

How often should I flush my black tank?
Flushing your tanks is an important maintenance task that you must perform if you want to avoid a smelly RV. The frequency of flushing the tanks depends on how often you use your RV.
It is advisable to flush the tank after draining it, especially if it has been in storage for more than a week or two.
However, RV owners who travel full-time in their RVs do not need to flush their tanks every time they empty them. That’s because most of these people empty their tanks several times a week.
Waste does not remain in the tank for long. The combination of frequent draining and the use of enzyme-based treatments can help them avoid constant flushing.
If your plant is starting to develop odors, it’s a good idea to increase the frequency of flushing. Many newer plants have special water connections that simplify the process.
Pro Tip: Black tank valves take a lot of abuse, which means they can get stuck. Here’s how to fix your stuck black tank valve in your RV!

Tips to protect the black tank of your motorhome from odor.
No one wants to have a smelly RV. We’ve compiled a list of our top tips to keep your black tank from smelling. Let’s take a look!
Keep the valve of the black tank closed
A rookie mistake that many RV owners make is leaving the black tank valve open when staying at a campground with a sewage hookup. Not only can this increase the odor nuisance in the RV, but it can also lead to a much bigger situation – the dreaded “poop pyramid.”
A black tank requires a mixture of solids and liquids to function properly. If you leave the valve on your black tank open, the liquid will quickly drain out of the tank.
This causes the solids to pile up in a pyramid shape at the bottom of the tank. If there is no liquid in the tank, these solids can solidify even more and cause clogs.
If you notice it in time, you may be able to fix the problem yourself. However, in severe cases, the help of a professional is often required.
Save yourself the trouble and keep your black tank valves closed until you’re ready to drain your tanks.

Use plenty of water
Water is your best friend when it comes to your black tanks. You must always use plenty of water when flushing. This will ensure that you have enough liquid to push out the solids as you empty your tanks.
Unless you’re spending the night outdoors or have some other reason to conserve water, always be generous with the amount of water you use to flush your toilet.
Although we encourage you to use plenty of water to protect your RV, there is no reason to be wasteful.
Use enough water to do the job, but don’t overdo it.
Get a quality tank treatment
A high-quality tank treatment such as Happy Camper, Camco’s RV Toilet Treatment or Walex Porta-Pak RV Holding Tank Treatment can reduce odors. However, consistency is critical when using these products. They’re no good if they’re in a cabinet and not in your black tank.
Whether you use your RV full-time or as a recreational vehicle on the weekends, you should use these products as part of your regular cleaning routine.
For tank treatments to be effective, you must use them regularly.
Regular emptying of your tanks
You don’t want waste to stay in your tank any longer than necessary. This can cause odor-causing bacteria to build up and pollute your RV.
If you are actively using your RV, depending on the size of the tank, it will probably only take a few days or a week of regular use to fill it.
It becomes problematic when the tank is filled with waste for weeks or months at a time. This is especially the case when owners store their vehicles without planned future trips.
In general, you should empty your tanks if more than a week remains before your next trip.
Pro Tip: If you’re going to empty your tanks at a public dump station, make sure you don’t break these unspoken RV dump station rules!
Check the tank vent
If you’ve ever climbed onto the roof of your RV, you’ve probably seen the fuel tank vent cover. This vent prevents gases and odors from building up in your tank.
If this vent is clogged or blocked, odors will look for the next best place to escape from the tank.
Unfortunately, the next best place leads directly to your bathroom. In this case, it’s only a matter of time before you use your sense of smell to determine that there’s a problem.
You can upgrade or replace a tank vent that is no longer doing its job. It’s actually quite simple, and we highly recommend the Siphon 360. We retrofitted this on our fifth RV, and it solved our stinky problem!
Check the seal of the toilet bowl
At the bottom of the toilet bowl, you should find a rubber gasket. This gasket is used to seal off the toilet bowl from the drain pipe that leads directly into the black tank.
Unfortunately, as these seals age, they can dry out, crack, or become damaged.
If you keep noticing odors coming from your toilet, put on a pair of rubber gloves and examine that seal.
Replacing or lubricating this seal can be a messy project, but it’s a fairly simple process that anyone with minimal DIY skills can do.
Related: Do you have a septic system at home? Ever wonder if you can dispose of your RV’s waste in a septic tank? Click to find out!
Flush your tanks often
If you want to prevent your RV’s black tank from stinking, you should flush the tank often.
This process is relatively simple and only requires that you fill the tank with clean water and dump it out. Repeat this process several times until the water is clear and free of solids.
Many modern RVs have water hookups that you can connect a standard size water hose to in order to fill the black tank with water.
We recommend using a designated water hose to clean the tank and not using the drinking water hose. Better safe than sorry!

Next item: Check out these 20 RV sewer accessories that don’t stink so you can have them all!
How to keep your RV black tank away from the smell
Maintaining your RV’s black tank is crucial to keeping it from smelling. By following the tips we’re sharing with you today, you can prevent unpleasant odors and ensure the proper functioning of your RV’s wastewater system.
Regularly draining and cleaning your black tank, using the right products and maintaining your wastewater system can help keep your RV smelling fresh and clean.
By taking care of your RV’s black tank, you can enjoy a comfortable and odor-free RV experience.