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Controlling RV Holding Tank Odors In High Heat

March 05, 2019

Controlling RV Holding Tank Odors In High Heat

Tired of dealing with high heat and strong RV toilet odors? In this article we cover the most common reasons why odors get worse in high temperatures. We also dig into: what causes strong odors in high heat, why your holding tank treatment may not be working, and what steps you need to take to control odors once and for all!

There are a number of reasons why you can get nasty odors in your RV, but for many, the odors become harder to control when it gets very hot out. It might be obvious but you heard it here first folks, heating up human waste is never good for odors! That might sound a little too simple so lets dig into what really can turn your camping holiday into a RV nightmare.


What Causes Odors To Increase In High Heat? 

There are a number of ways that odors can become a problem in your RV. Here are the most common culprits:



Not having enough water in your black water tank can have several adverse effects.

  1. Waste Above The Water Line Smells Extra Strong
  2. Sewer Gas Can Seep Into Your RV If There Isn't A Water Barrier
  3. Beneficial Bacteria Can't Survive Without Plenty of Hydration
  4. Hot Tank Temperatures Can Increase Strong Smells

Waste Above The Water Line

When human waste (poop) is exposed above the water level in your holding tank, it can cause very strong odors. Think about a portable toilet at your local state fair. When the poop gets above the water line, the smells increase exponentially. This has the same effect inside your RV Holding Tank.

In hot weather, some of the water that you have added to your holding tank will evaporate, exposing the waste in your RV to the air. By not having a layer of water covering your waste, it is possible you can experience very unpleasant odors from your RV toilet.

Solution: Use an Ample Amount Of Water - We recommend holding down your toilet flush pedal for 10 seconds each time you flush. 

Water Barrier

If sewer gas is allowed to seep into your RV you will experience strong odors.  

Solution: Keep Several Inches of Water In Your Toilet Bowl At All Times.


Another thing to keep in mind is the type of bacteria that is inside your holding tank. 

One type of bacteria that is commonly found in RV holding tanks is anaerobic bacteria. Anaerobic bacteria is responsible for almost all of the bad smells that you get in your holding tank. This naturally occurring bacteria that comes from your stomach gut breaks down waste and releases hydrogen sulfide gas - that all too familiar methane smell. These odors created by anaerobic bacteria only get worse in hot weather. 

Solution: Treat Your Tanks With a High Quality Bacteria-Based Holding Tank Treatment. 

A good bacteria-based tank treatment introduces aerobic bacteria into your tank and forces out the anaerobic bacteria. These healthy aerobic bacteria break down waste and release carbon dioxide and water, instead of hydrogen sulfide gas, thereby eliminating tank odors all together. 


Aerobic bacteria thrive in temperate conditions, therefore it is really important that you keep your holding tanks from getting excessively hot. The last thing you want is those anaerobes returning.

Solution: Regulate Tank Temperatures - Add ice or cold water to your black water tank to keep temperatures under 85°F

By adding cold water or ice to your holding tank, you can keep tank temperatures within a viable range for the beneficial bacteria inside your tank.

Temperature Cont.

If you can't keep the tank temperature at an ideal range (45°F - 85°F) using ice or cold water, you may want to try using a mineral/salt holding tank treatment. We recommend Unique Tank Odor Eliminator. It works quickly to remove odors when you can't control tank temps.


Why Am I Still Getting Odors? I Use a Holding Tank Treatment!

Contrary to popular belief, not all RV toilet chemicals are created equal. Different RV chemicals have different strengths. When it comes down to it, certain chemicals can only do so much to control odors. Lets go over the strengths and weaknesses of each.


Chemical/Odor Masking

Unfortunately, many RV toilet chemicals that are designed to masking smells perform poorly in high heat. They fail because the odors in your holding tank are incredibly potent and the chemicals can't compensate for the sheer volume of odor.  The reality is, you can't just cover the problem with an odor masking RV toilet chemical and hope it works. The proper treatment has to take care of the solid waste and the anaerobic bacteria in your RV holding tank. 


Bacteria holding tank treatments like RV Digest-It may have limitations in high temperatures but are, by far, the best option for all-around care in your tank. Bacteria holding tank treatments are most effective at removing odor between 45°F and 85°F. If your holding tank gets above or below that temperature range, you may have decreased efficiency and bacteria culture drop off. Within that range, bacteria will perform incredibly well to reduce odors and break down solid waste. When temperatures in your holding tank move outside of that range, you will need to regulate your tank temperature to make sure the bacteria is working efficiently or use an odor reducing product that isn't limited by tank temps


Though good for waste digestion, unfortunately, enzymes do little to nothing for dealing with odors in high heat. The only instance where they might help mitigate some smells is if there is an odor masking chemical added to the treatment, but as we mentioned above, odor masking is not a reliable solution. The enzymes themselves will not help with smells in high heat.


Often, the best type of RV tank treatment to eliminate odors in the highest heat is a mineral/salt combination. The mineral/salt combination works quickly to eliminate odors and is often the very best option for uncontrollable odors. Although mineral/salt blends are great for eliminating odors, there are a few draw backs. They can be hazardous to humans and the environment and are often not the safest treatments on the market, so be sure to handle these products safely according to their label.

At Unique, we strive to make safe products, but we also want to provide some of the best solutions for your holding tanks. Contrary to other mineral/salt treatments, we package Tank Odor Eliminator in a water soluble pouch to ensure safe handling. 


RECAP: Steps to Control Odors In High Heat 

  • Use an Ample Amount Of Water - Flush your RV toilet for 10 seconds after every use.
  • Keep Several Inches of Water In Your Toilet Bowl At All Times.
  • Use a Quality Waste Digesting Holding Tank Treatment - By breaking down the waste, ensure no waste is sitting above the water barrier. 
  • Regulate Tank Temperatures - Add cool water or ice to your black water tank to keep temperatures under 85°F AND/OR use Unique Tank Odor Eliminator to remove odors from your RV holding tank.

Ultimately we recommend using RV Digest-It as your standard treatment for your normal use and supplement with Unique Tank Odor Eliminator to control odors in high heat. 



Tackling odors in high heat can be a smelly endeavor and it takes education and diligence on your behalf to effectively to deal with recurring problems. This article addressed the actionable ways to deal with odors in a fully functioning RV. There is always a possibility of something being faulty with your tank ventilation or valves. If you are having ventilation issues or leaky valve issues, it will be much harder for you to deal with high heat odors until everything is working properly. At the very least these tips will help you deal with keeping smells under-wraps as you travel this year!


Further Reading

Did you like what you just read? Check out some of our other related resources!

Preventing Clogs In Your Holding Tank
Cleaning Holding Tank Sensors
Eliminating Tank Odors


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