Roborock Dirty Water Tank Smells Bad? 5 Fixes That Actually Work

Disclosure: Some of the links on this website are affiliate links. It's possible for me to receive a commission at no extra cost to you.

Quick answer: A Roborock dirty water tank smells because used mop water sits in the tank between runs and grows bacteria. To fix it: empty and rinse the tank after every clean, then deodorize with a teaspoon of white vinegar or a silver ion pod in the clean-water tank. For a deeper reset, wash with mild dish soap or a diluted bleach solution. The five methods below cover every option.

Emptying your robot vacuum’s dirty water tank can often release an unpleasant odor strong enough to be quite bothersome. This common issue among robot vacuum users has led to the development of various strategies to tackle the problem effectively. It can happen to any robot vacuum with a clean or dirty water tank, for example, many of the high-end Roborock models such as a Q Revo, S7, S8 Ultra or S8 MaxV Ultra can accumulate bacteria in their dirty water tanks.

To prevent the growth of bacteria and the development of odors, it’s vital to empty the dirty water tank after each use. Allowing water to stagnate in the tank creates an ideal environment for bacteria, leading to worse smells over time.

Here are some factual tips and methods to help neutralize those unwanted smells.

Using Soap and Water to Remove the Dirty Water Tank Smell

A popular method involves adding a splash of mild dish soap or hand soap diluted in water directly to the dirty water tank. This simple solution can cut through grease and neutralize bad odors efficiently. However, it’s crucial to avoid using foaming soaps as they can lead to overflow and potentially damage the vacuum.

Using Vinegar to Remove the Dirty Water Tank Smell

White vinegar serves as a natural disinfectant and deodorizer, making it an excellent choice for combating odors. Adding just a small amount, such as a teaspoon, to the dirty water tank can significantly improve its smell by providing a thorough cleaning and odor-fighting action.

This VacuumCat article also suggests white vinegar and Silver Ion Pods

Using Clorox to Remove the Dirty Water Tank Smell

Some users find success with a diluted bleach solution, available on Amazon, for its strong disinfectant properties. Nonetheless, caution is advised when using bleach, as it can potentially weaken certain types of plastics. Always refer to your robot vacuum’s manual for compatibility issues and consider non-chlorine bleach alternatives when necessary.

Using Silver Ion Pods to Remove the Dirty Water Tank Smell

Silver ion pods, available on Amazon, offer an innovative approach to tackling odors and bacteria in robot vacuums. By placing a pod in the clean water tank, users have noticed not only a reduction in unpleasant smells but also an extended cleanliness of the dirty water tank. This effect is attributed to the water flow direction in the robot, allowing the silver ions to benefit both the clean and dirty tanks.

While some users opt to add pods to both tanks, it’s generally unnecessary. The process ensures that as the robot cleans, silver ions are distributed across the floor and into the waste water tank, ensuring a more hygienic cleaning cycle and fresh water storage, as well as cleaner mops and recycled waste water.

Other helpful tips for removing Bad Smells from your Robot Vacuum’s Dirty Water Tank

Fresh Water Matters: Using filtered water in the clean water tank can also help. Minerals from hard water may contribute to the development of odors.
Mop Maintenance: Ensure that your robot mop or the mopping part of your vacuum dries completely after each use to avoid mildew and musty smells.
Frequent Cleaning: Regularly rinsing the dirty water tank with clean water can help remove residue and prevent odors from settling in.

Still smells after cleaning the tank?

If you’ve done the tank routine and your Roborock still stinks, the smell is coming from somewhere else — usually the mop pads, the filter or the dock. Walk through every source here: Why Does My Roborock Smell Bad? (And How to Actually Fix It).

If you’ve spotted black or pink specks in the tank, that’s mildew — see How to Get Rid of Roborock Water Tank Mold.

Frequently Asked Questions

Why does my Roborock dirty water tank smell so bad?

Used mop water sits in the dirty tank between cleaning runs. Bacteria multiply in that warm, stagnant water and produce the swampy or sour smell. The fix is to empty and rinse the tank after every run instead of letting it sit.

Can I put white vinegar in my Roborock water tank?

Yes. A teaspoon of white vinegar acts as a natural disinfectant and deodorizer and is safe for the tank. Avoid foaming soaps (they overflow) and only use bleach heavily diluted, since it can weaken some plastics.

How do I stop my Roborock dirty water tank from smelling in the first place?

Empty and rinse the dirty tank after every run, let the mop pads dry between cleans, use filtered water if you have hard water, and drop a silver ion pod in the clean-water tank to keep both tanks fresher for longer.

Does this work for other robot vacuums like Eufy, Dreame and Tineco?

Yes. The same bacteria-in-stagnant-water problem affects every robot mop with a dirty water tank. The soap, vinegar and silver ion pod methods all work across brands.

Why does my Roborock mop smell bad even after I clean the tank?

If the tank is clean but your Roborock still smells, it's usually the mop pads. They stay damp under the robot and go mildewy, giving off a musty, wet-dog smell separate from the swampy tank smell. Dry the pads between runs, wash them every week or two, and replace them once they smell even after washing.