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When it comes to RV upkeep, cleaning black tanks is usually not at the top of anyone’s list but it is essential to keep your vehicle in working order.

Cleaning your black water tank is not rocket science and most standard RVs these days are designed to make the experience as clean and easy as possible. However, there are certainly some dos and don’ts to cleaning your RV black tanks that you should be aware of.

To clean your black tanks you will first need to connect your waste hose to a sewage disposal system. You can then drain your tank until it is empty. Next, pour water into your tank for an additional flush until everything is drained. Lastly, pour a black tank treatment into your toilet.

When it comes to traveling around the United States, three is really no better way to do it than to get in your RV and drive across the country. There are countless places to see and camping is a way of life for so many RV travelers. But traveling in an RV requires a bit more attention to detail and upkeep than doing so in your average car. An RV is quite literally a home on wheels, which means that you are going to have to properly maintain your vehicle if you want to keep your home happy. An area that you should never neglect is your RV’s black tank. Your black tank is what hold’s all of your RV’s waste. This does not include the water that drains from your sinks or shower, as this all flows into your greywater system. The blank is where everything from your toilet goes in - your wastewater tank. No one wants to deal with sewage waste but, trust me, the better your upkeep is with your black tanks, the less work you will have in the long run. To help you understand this further, we are going to take you through the whole process of cleaning your RV’s black tank.

After extensively researching RV maintenance and upkeep, I have been able to gather enough information to determine how to clean black tanks. My research has taught me that cleaning RV black tanks is a lot easier if you do it routinely.



When to Clean Your RV Black Tank

There can be some confusion when it comes to cleaning RV black tanks. Specifically - when does it need to be done? Some folks prefer to clean their black tanks as soon as they are just under full and others like to do it as frequently as possible - with some people cleaning them every couple of days.

As a standard, you should try to clean your black tanks every 3 or 4 days - if your RV has been in regular use. If you feel like you are not using your toilet all that much, you should be able to get away with doing it once a week.

We have found that the best time to clean your black tank is when it is ⅔ of the way full. Most modern RVs will have a tank sensor for this to make life easier on you, which will give you an exact indicator of when your black tank is at this level. However, one of the most common faults that we see with RVs is that these new-age sensors often die out pretty quickly and stop functioning.

If that is the case, you can always check on your black tank the old-fashioned way. Simply grab a flashlight, look inside of your RV’s toilet, and have a peek inside. If you are seeing that the water level inside of your black tank is at or near the level of your floor level, then it is a good sign that you should probably dump your sewage sooner rather than later. The reason why you want to dump your black tank when it is two-thirds of the way full is that this is when it will have optimum flow.

Dumping your black tank too frequently can lead to sewage being too solidified, which can cause clogs. This may result in needing to do considerably more black tank cleaning than needed. In addition, waiting until the last minute can potentially result in the same thing. That is why the best time to flush your sewage is between 50% and 75% full.

Cleaning Your RV Black Tank

If you are planning on dumping your black tank, you want to always ensure that you are doing so responsibly. When you dump your tank, it must be at an approved and authorized dump station.

There are dump stations that specialize in this kind of service, however, if you are on the road - then you will find that there are plenty of RV campgrounds that offer this service included in your stay.

Alternatively, you can always drive up to one when you are on the road and drain your tanks for a fee, which is a very important resource to utilize if you are dry camping. Now, let’s get into the process of cleaning your RV’s black tank.

Supplies & Equipment

Before you can begin cleaning your RV’s black tank you are going to want to have all of the right supplies and equipment ready to go to make the process quick, clean, and efficient.

Whenever dealing with your black tank, you should always have a pair of gloves on. Chances are that you will not be getting your hands too dirty if you do everything right but nonetheless, keeping things as sanitary as possible is always a good idea when it comes to your RV’s black tank. In addition, you should have the following items:

Seethrough Elbow Fitting

Your RV likely came with a connecting elbow pipe so that you can connect your hose to a sewage line.

There is no way that you can drain your RV’s black tank without this component. The standard elbow fitting that your RV came with should get the job done just fine but we would highly recommend buying a
seethrough fitting - if you don’t already have one.

So many RV travelers these days are using these fittings as they are much more practical than non-transparent options. It can be very difficult to see how your RV tanks are flowing and when the job is done without one. This results in some people waiting around excessively for their tanks to drain or taking out their fitting before the sewage had fully drained. A seethrough fitting will give you a definitive idea of how your black tanks are flowing and when they are finished.

Sewer Hose Support

A lot of RV travelers tend to overlook the importance of having a collapsable RV ramp for their sewage hoses.

It is quite common for most people to simply connect their RV hose to the sewage-disposal while leaving the hose on the ground for it to drain. This is not going to be a problem if the flow is moving downhill but if there happens to be an uneven surface or even one that is flat, you are going to have poor drainage.

Getting yourself a sewer hose support ramp is going to be an excellent investment for draining your RV’s black tank and you will find that it will make the process a whole lot easier. You take the lightweight support system and create a platform for your sewer hose to sit on top of so that it can drain out evenly.

While we are on the topic of sewer hose support, one of the best ways to seal the deal with draining your black tanks efficiently is going to be to have a second hose handy. Most of the time you will not need to use it but you will find that some campgrounds have their sewer disposal considerably further away than a single hose can reach.

To save yourself the trouble of maneuvering your RV awkwardly around the sewage line, simply get yourself a second hose and avoid the headache altogether.

Connection & Drainage

With all of your equipment ready, you can begin draining your tank. You will first have to connect the drainage hose to the campground sewage hole. Next, connect the hose to your RV’s black tank output. Make sure that the hose is securely fastened to the output before you begin doing any draining.

If you haven’t already, cleaning your toilet is highly recommended before you begin doing the next steps. If you feel like your tank does not have enough fluid in it, pouring a gallon of water into your RV toilet will make things flow better.

Initial Sewage Flush

You can then pull the black water tank valve. The black water tank valve is what opens up the flow of your RV’s sewage hose connection system. Some high-tech RVs have a push-button feature for this but most do not. Your black water tank valve will probably be located towards the tail end of your RV on its right or left side.

After you have pulled the black water tank valve, you will see sewage from your RV start to flow out through the hose. This is where the seethrough fitting for your hose really comes in handy as you would otherwise be doing this part of your RV upkeep blind.

With your black water tank valve pulled, give your wastewater tank at least 5 or 10 minutes to flow out before you check up on it again. If you found that the flow of your black water tank was not moving through properly, you may have a lack of fluid in your tank.

In this case, you may want to fill up your tank with water - but not too much. A couple of gallons should be just fine. This will encourage that everything moves through well.

If you do not have a flush system, then you will need to use a tank wand for this part.

Additional Flush

If you want to get your black water tank clean, you are going to want to do more than one flush to seal the deal. Once everything has drained out on the initial flush, close your black water tank valve.

Many people make the mistake of thinking that their waste water tank is completely flushed at this point but in actuality, there is still probably a whole lot more in there that you are going to want to get rid of to get your tank clean.

We recommend getting just about an entire tank of water in there again to perform an additional flush. You can grab a bucket, use a fresh water hose, or even a cleaning wand for this. Pour the water into the waste water tank with your black tank valve disengaged.

Once the tank is relatively full, you can pull the black water tank valve to release the fluid. If you check your seethrough fitting you will be amazed by how dirty your tank still is. This second black water tank flush should get rid of the rest of the sewage in your system.

Once everything has drained disengage the black tank valve again. If you saw that the fluid was transparent, then you should be good to go - especially if you have only been on the road for a short period. However, if you are draining your tank after a long trip or are storing your RV for a while, then you should repeat this process at least once or twice more.

Black Tank Treatments

Once you have done your black tank flush, you are going to want to add a chemical product into your system to keep things clean and to prevent clogs.

For this, you will want to purchase a black tank treatment additive. This is essentially a chemical that you can add to your black water tank after you have completed your flush. Pour roughly 2 or 3oz of the additive into your toilet with your black water tank valve disengaged.

You can then pour a gallon of water into the toilet to let the chemical spread around the tank. This should pretty much finalize the procedure of cleaning your RV’s black tank - provided that everything drained out properly.

Smell Test

You should probably be okay with your tanks at this point but you will still want to confirm that everything has fully been cleaned and drained. This is particularly important if you are planning on storing your RV for a while - especially if you are putting it away for the winter.

Perform a smell test as this is the best way to make sure that the tank drained properly. Close all airflow to your RV and let the vehicle sit for 5 or 10 minutes to see if there is an odor leakage. You can then return to your RV, open up your toilet bowl, and have a smell. If you do not notice any unpleasant odors then you should be good.

If there are any bad smells, you will need to fill up your toilet until the wastewater has fully drained. In this case, fill the tank up with water, pull the black tank valve, and repeat the above-mentioned process.

A common reason that black tanks do not drain properly is due to bad toilet paper that does not process well. You should try using septic safe toiler paper for this, as it was designed to flush the best through black tanks. ‘RV Toilet Paper’ has been known to not work as well. Instead, use two-ply septic-safe toilet paper.