One of the most common questions we receive is about the best way to clean RV black water tanks. Whether you’re currently dealing with a problem, or you simply want to establish good tank care habits, deep cleaning your black water tank is the perfect place to start.

For tips and information about deep cleaning RV gray water tanks, please visit our guide that covers How to Deep Clean RV Gray Water Holding Tanks.

Key Points About Cleaning RV Black Water Tanks

• Black water tanks should be deep cleaned and deodorized at least twice a year to maintain proper functionality.
• Deep cleaning RV black water tanks is easy and can be completed overnight.
• Full-time RVers will need to approach the process differently if they need to use their black water tank while deep cleaning.
• Popular techniques and homemade treatments circulating online and throughout the RV community may not be the most effective or safe.

Why is Deep Cleaning RV Black Water Tanks Important?

Regularly cleaning your black water tank is important because keeping the holding tanks clean and free from build-up is key to avoiding clogs and foul odors in your RV. These issues can arise if waste is allowed to linger in crevices, tank ledges, sensor probes, and low points in your tanks, leading to complications at the most inconvenient times.

Don’t worry, it’s common for waste to accumulate in even the most well-maintained tanks. You may be doing everything right by using high-quality tank treatment and following the recommended maintenance procedures, but your black water tanks still need periodic deep cleaning treatments. Deep cleaning your tanks twice a year helps to fully reset them and ensure they’re completely free from waste, much like visiting the dentist twice a year gives your teeth that extra level of clean you simply can’t achieve on your own.

By maintaining a regular deep cleaning schedule, you can prevent future problems from arising. We’ll take you through each step of the cleaning process so that you can easily and comfortably maintain your RV black water tanks with confidence.

Best Way to Deep-Clean RV Black Water Tanks

Thankfully, deep cleaning RV black water tanks is simple and straightforward, making regular maintenance easy to perform.

Supplies you need to deep clean your black water tank:

• Water
• Bacteria- and enzyme-based cleaner (Unique Clean-It)
• Time

There is a reason why Clean-It is the best selling black tank deep cleaner on the market! It is the strongest, most effective tank cleaner in the industry, it’s safe to use in all RVs and motorhomes, and is 100% satisfaction guaranteed. When you use Clean-It, you are essentially hitting a “reset” button on your black water tank for a fraction of the price. Professional tank jetting services can be a hassle and are costly, while Clean-It is extremely convenient, affordable, and just as effective.

Using Clean-It allows you to spend more time enjoying your RV, and less time thinking about your holding tanks.

Steps for deep cleaning an RV black water tank:

1. CLOSE YOUR BLACK TANK VALVE
2. Fill your black tank with water.
   

   Note that it is crucial to fill the tank as much as possible because cleaning only occurs where water is touching.

3. Dump one entire bottle of Unique Clean-It into your 40 gallon tank.
   

   Clean-It can usually effectively clean and deodorize your tank in approximately 12 hours —- however, the longer you let it work, the better.

   No amount of Clean-It is too much, and you can feel free to let it sit for days, weeks, or months, as it will not do any damage to your RV. In fact, the more time you give Clean-It to work, the greater your results will be.

4. Open your black tank valve and dump your tank.
5. Rinse your tank thoroughly.
   

   If you do not have a built-in rinser, you can use an RV holding tank cleaning wand or external tank rinser that connects to your discharge line, but our preferred method of rinsing is to completely fill your black tank with fresh, clean water, then dump the tank.

   Do this twice and your tank will be rinsed more thoroughly than any wand or device can provide.

6. CLOSE YOUR BLACK TANK VALVE (always keep closed unless you’re dumping).

It’s that simple! For recreational campers and weekend warriors, we recommend performing black water tank deep cleans at least twice a year. A general rule of thumb is to clean it once at the beginning of RV season and once at the end.

If your RV is stationary and rarely moves, we suggest performing a deep clean every 60 days since the contents of your tank will generally accumulate more in certain areas.

Full-Time RVers: Modified Black Tank Cleaning

If you are a full-time RVer, we know that cleaning black water tanks can be complicated when you are trying to use the tanks at the same time. We recommend that full-time campers should clean their black water tanks every 10 dumps with Unique Clean-It. Maintaining this cleaning schedule will ensure that the holding tanks work properly and will keep odors at bay.

Modified steps for deep cleaning a full-time RV black water tank:

1. Dump your black water tank.
2. Rinse your black water tank thoroughly to remove as much waste as possible.
   

   If you do not have a built-in rinser, you can use an RV holding tank cleaning wand or external tank rinser that connects to your discharge line, but our preferred method of rinsing is to completely fill your black tank with fresh, clean water, then dump the tank.

   Do this twice and your tank will be rinsed more thoroughly than any wand or device can provide.

3. Add one bottle of Clean-It per black tank.
   

   Once you’ve added the Clean-It, you can continue regularly using your toilet. Ideally, you should let the solution work for 5-7 days prior to dumping, if possible. The more time you give Clean-It to work, the better your results will be.

   The best option is always to deep clean without using the tanks, but deep cleaning while using them will still help prevent buildup and other tank issues. Just a friendly reminder, Clean-It can only work in areas where water is touching, so tank walls that are not submerged will not be cleaned.

4. Dump your black water tank.
5. Rinse your tank thoroughly following rinsing guidelines.
6. CLOSE YOUR BLACK TANK VALVE (always keep closed unless you’re dumping).

For thorough details about black water tank care for full-time RVers, refer to Full-Time RVing: The Definitive Guide to Treating Your Tank.

Deep Cleaning RV Black/Gray Water Combo Tanks

Combo tanks can sometimes cause confusion when it comes to cleaning because it can be unclear what to do when using them as both a black and gray water tank.

Here are a few tips about how to clean your combo tank based on your usage:

• Using a combo tank as only a black water tank, refer to the steps in the Best Way to Deep-Clean RV Black Water Tanks section above.
• Using a combo tank as only a gray water tank, refer to our guide about How to Deep Clean RV Gray Water Holding Tanks.
• Using a combo tank for black and gray water, start by cleaning it as if it were solely used as a black water tank. If you think there may be excessive amounts of grease or soap scum that were not removed with the black tank cleaning method, then follow the gray water tank cleaning steps as well.

Cleaning combo tanks can be as easy as long as you remember to clean them based on how you use them. When in doubt, start by using the black water tank cleaning steps and then follow with gray water tank cleaning. Using both methods never hurts and ensures all your bases are covered.

Common Black Water Tank Cleaning Advice in the RVing Community

There is a lot of information out there about how to clean your RV black water tanks, and it can certainly be difficult to determine what methods are most effective. The RVing community openly shares a lot of home remedies and commonly used methods for deep cleaning black water tanks, but unfortunately, the results don’t always live up to the hype.

Before you consider taking deep cleaning advice from other RVers, we encourage you to read our article about Common RV Holding Tank Myths Debunked. This information may help guide you through which techniques are viable, and which ones you’ll want to avoid, and why.

The Unique Method is the only method you need to prevent the majority of tank problems before they occur. Developed over 30 years of solving wastewater problems professionally, The Unique Method cuts through the waste, and the bad advice, to give you problem-free holding tanks long term. All you need to do is follow the simple set of rules and use the right products — like those available from Unique Camping + Marine that contain bio-enzymatic (bacteria and enzyme) formulas to eliminate odors at the source, breakdown solid waste, and help maintain sensor probes simultaneously —- to solve 99% of your RV wastewater problems.

RV Black Water Tank Cleaning: Review

Deep cleaning your black water tank will allow you to enjoy stress-free RVing adventures. Maintaining a regular cleaning schedule will reduce the probability of RV clogs and unpleasant odors, and will help your wastewater systems run smoothly for years. Whether you are a seasonal or full-time RVer, Unique Clean-It has your RV black water tanks covered.

If you need additional information and advice about deep cleaning RV gray water tanks, visit our guide explaining How to Deep Clean RV Gray Water Holding Tanks.