RV Grey Water Tank Smells – What to Do?

Are you struggling with a smelly grey water tank in your RV? Traveling can be fun and exciting, but a stinky tank can put a damper on things. We dug deeper into the situation, researched top sources, and found why grey water tanks smell and how to fix the problem. See our findings below. 

While it may not be possible to completely rid your grey water tank of odor, you can minimize the smell and prevent it from returning. The most important step is to clean and sanitize your tank regularly. There are also products you can purchase specifically for reducing odor in your RV's grey water reservoir.

Keep reading for more information on cleaning products and methods for eliminating odors in your grey water tank, as well as steps you can take to prevent odor in the future. We will also discuss the reasons for the smell, how often to empty the tank, and much more. 

A man attaching a blue waste hose to the grey water tank, RV Grey Water Tank Smells - What to Do?


How to Eliminate Odor in Your Grey Water Tank

Grey water is the waste from your sinks and shower/bathtub in the RV. Although it may seem like this type of waste would not smell bad, it is mixed with things such as soap scum, dirt and debris, skin cells, and bodily fluids. In addition, all this waste accumulates in the tank and stays there until you dump it, causing it to become stagnant and possibly moldy. 

The RV is a confined space, so smell radiates throughout, making it unpleasant and difficult to withstand. The most effective method for ridding the RV of odor from the grey water tank is by cleaning and sanitizing the tank and emptying it regularly. You can purchase products that are made specifically for this purpose. It's also important to disallow food particles from making their way down the drains, which cause a nasty smell when it begins to rot. 

Cleaning the Tank

An RV waste water dumping station

Simply emptying the tank is not enough. While you don't have to thoroughly clean it each time you dump the contents, you should do so approximately every three to four dumps. After you empty the reservoir, use a water hose to run water back into the tank.

For even better results, you can purchase a hose with an attached swivel stick meant to clean out holding tanks. Twist the hose as the water is spraying to blast away stuck-on gunk. Although it is labeled for use in black water tanks, it works great in grey water tanks as well. 

You can find an RV hose and swivel stick on Amazon. 

Vinegar and Baking Soda

According to Jayco, you can pour vinegar down the sink and bathroom drains. This will help get rid of sludge and slime buildup along the sides of the pipes. Each time you drain the grey water reservoir, sprinkle a couple of teaspoons of baking soda in the sink. Swish some water around the area and let it go down the drain. This will help remove the smell in the tank. 

Prevent Food from Going Down the Drain

While it may seem like a harmless act, allowing food to wash down your kitchen drain can be a disaster once it begins to decompose. It will combine with the other particles in the tank, leaving you with a stinking, rotting mess below. The most effective way to keep food from falling down the drain is to place a mesh sink strainer in your drain. It will catch any rogue food particles, allowing you to dump them in the trash. 

You can find RV mesh sink strainers on Amazon. 

Grey Water Tank Deodorizing Products

Before using any products in your tank, check your RV's user manual to ensure you don't put anything in the reservoir that will harm it. Some great products on the market are manufactured specifically for RVs to help eliminate and control foul odors in your grey water reservoir. You can find our recommendations below:

  1. Thetford 15842 Grey Water Odor Control
  2. PRO-PUMP/TST Odor Remover for RV Holding Tanks
  3. Camp Champ RV Odor Abate

1. Thetford 15842 Grey Water Odor Control 

This product is chlorine-free and easy to use. Not only will it eliminate nasty smells in your tank, but it will also get rid of odors that radiate from your vents. It is made using a 100% biodegradable formula to break down soap scum, residues from cleaning products, and even tough grease. Pour the recommended amount down the drain and let it work its magic. 

You can find Thetford Grey Water Odor Control on Amazon. 

2. PRO-PUMP/TST Odor Remover for RV Holding Tanks

If you want a product that removes odor immediately, Pro-Pump is the way to go. It removes both grey water and black water smells and prevents them from returning. Pour the biodegradable, non-toxic formula down the drain and wait for it to begin breaking down particles. 

You can check out ProPump Odor Remover on Amazon. 

3. Camp Champ RV Odor Abate

Camp champ works on both black and grey water holding tanks. The convenient design allows you to premeasure the proper amount before pouring it into the sink or toilet. For best practices, add the formula to empty reservoirs each time you dump the contents. 

You can find Camp Champ on Amazon. 

Grey Water Tank Cleaning Products

Deodorizing products are essential; however, it is also important to use a cleaning agent in your holding tank to get rid of bacteria and other nasty buildups. Upon adding cleaning solutions to the tank, you can also add some water and drive the RV for a bit. This will agitate the contents, breaking up particles and dislodging them from the sides and edges. The following products are great for this chore: 

  1. Thetford Tank Blaster Holding Tank Cleaner
  2. Roebic RVM-Q-6 RV & Marine Holding Tank Treatment
  3. Valterra Odorlos V77012 Holding Tank Treatment

1. Thetford Tank Blaster Holding Tank Cleaner

Thetford Tank Blaster is designed for use in both grey and black water holding tanks. To use, drain your tank, add the recommended dosage, and add fresh water to the reservoir. Allow the mixture to sit overnight. The following day, drain the reservoir again. 

You can check out Thetford Tank Blaster on Amazon. 

2. Roebic RVM-Q-6 RV & Marine Holding Tank Treatment

Roebic Tank Treatment is very easy to use in both grey water and black water tanks. It is environmentally friendly and uses a blend of good bacteria to break down waste. After dumping your grey water reservoir, pour 4 ounces down the sink. There is no need to add water or drain later. Just allow the product to remain in the tank until the next time you empty the contents. 

You can find Roebic RVM-Q-6 RV Holding Tank Treatment on Amazon. 

3. Valterra Odorlos V77012 Holding Tank Treatment

Last but not least, try Odorlos Tank Treatment. It works well in extreme temperatures and is environmentally friendly, effective, and easy to use. Upon emptying your tank, sprinkle the suggested amount of powder into the sink. Next, pour the required amount of water, leaving the mixture in the tank until the next time you empty it. 

Check Out Valterra Odorlos V77012 Holding Tank Treatment on Amazon.

Frequently Asked Questions

A man dumping waste water from the grey water tank

How do I keep my grey water tank clean?

Some excellent products on the market will help keep your grey water tank clean. Most can be poured directly down the drain upon emptying the tank and left there until the next dumping. You can also use a hose in the tank emptying hole to spray water into the reservoir. 

How do you get rid of grey water?

First, you should always dump the black water tank before emptying the grey water. To get rid of grey water, place a hose in the designated hole, and pull the lever, releasing the grey water. Do not empty the contents onto the ground. Instead, you should also locate the nearest RV dump site. If you prefer, you can empty the tank into a portable dump station until you can make it to the designated spot. 

Check out the Camco Rhino 28 gallon portable RV waste holding tank on Amazon. 

Is it OK to dump grey water on the ground?.

It is never okay to dump grey water on the ground. Although it may seem harmless, grey water is still a waste product and should only be disposed of in designated areas. You should find the nearest RV dump station and empty your tank there. 

How often should you empty a grey water tank?

Since each situation is different, there is no definitive answer to how often you should empty your grey water tank. An RV containing one person will not have to be dumped as often as an RV hosting a family of four. Some people also use more water than others.

However, most RVs contain a sensor that tells you how much waste is in your tank, no matter the situation. Check it regularly, and clean it out once it gets to about 75% full. That being said, if only one person is occupying the RV, they can typically wait a week or so before emptying the grey water reservoir. 

How long can an RV go without dumping?

The period of time an RV can go without dumping will depend on how often you use it and how many people are involved. However, you don't want to dump it too soon. You should allow the tank to fill at least 2/3 of the way before dumping to allow particles to break down. If you don't utilize the RVs grey water tank regularly, you should still dump it a few times a year to keep it clean and odor-free. 

Can I put bleach in my grey water tank?

According to Jayco, bleach and other chlorine products or drain cleaners are not recommended for your grey water tank; although, some people will tell you otherwise. Over time, bleach/chlorine will begin to eat away at your gaskets, causing you to have to replace them. 

How do I sanitize my RV water tank without bleach?

Although bleach is not recommended for use in your grey water tank, there are many sanitation products on the market which are made specifically for RVs. Above, you will find three of our most recommended products for cleaning and sanitizing your grey water holding tank. 

In Closing

Grey water tanks do not contain the same potent waste as black water tanks. However, the combination of skin cells, food particles, and soap scum will still build up in your tank and begin to smell foul. With proper cleaning and prevention techniques and products, you can keep your holding tank from smelling up the entire RV. 

If you have more questions, we are here to help. You may find the following related posts to be helpful. You can also check out our blog for more questions regarding your RV and much more:

How to Remove the Grey Water Tank from an RV? 

How Much Does an RV Grey Water Tank Cost to Replace?

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