How to Dump and Clean Your RV's Black Water Tank

Dumping and cleaning RV sewer tanks are jobs that most recreational vehicle owners dread because these can be messy, smelly jobs to do.

Most people don’t know whether they are doing them correctly or even which tools and chemicals are the best and safest ones to use.

However, once people understand what it is they need to do and the equipment they need for these jobs, caring for black water tanks becomes a relatively simple task.

Every product I share with you here are ones that my husband and I have used successfully for many years because they work!  There are undoubtedly others that work well, too, but these are the ones we have personal experience with.

RV Sewer Tank Cleaning Is Important

Wear Protective Gear

No matter which job you are doing, it’s important to protect yourself and your clothing from any toxic waste that comes out of your tanks.

For this reason, you should remember to wear
  • latex or rubber gloves,
  • rubber boots or shoe covers,
  • safety glasses and
  • coveralls
whenever you are cleaning or dumping, and always make sure to keep some liquid soap and paper towels handy so that you can clean up at an outside spigot after finishing either of these tasks.

The safety glasses are particularly important because you don't want toxins splashing into your eyes while you're taking care of tank cleaning chores.

Use The Right Products and Tools

RV plumbing is much more fragile than that in houses, so you have to take great care with the cleaning products and tools you use.

Here is a list of the products and tools that have worked well for my husband and myself for many years:

a tank cleaning wand such as this one:

(click link to buy)

regulation RV sewer hoses (one long and one short),

(click link to buy)

a clear hose adapter that will help you to see what is coming out of the tank,

Eco Friendlly Sewer Tank Treatment
(click link to buy)

a package of ecologically friendly enzyme tank treatment and
some liquid bleach

You will need the first three products for every day dumping, and all for deep cleaning.

Most of these items are specialty products than can be tricky to find, which is why I've provided links to some of them.

You also should make it a point to 
  • use toilet paper that is made especially for RV use,
  • avoid heavy duty household cleaning products or brushes and
  • use a donut when connecting to campsite sewer outlets. (Most parks require you to use donuts to make sure that the odors from the sewer are controlled.)
Dumping Vs Cleaning

Many people think that dumping tanks is the same as cleaning them, but this is not true.
  • Dumping takes place every day or so and empties the contents.
  • Cleaning takes place as needed, is done following a dump, and sanitizes the tank.
Thus, each has its own process.


When you set up camp or use a dump station, always use a see through connector when hooking your sewer hose into an outlet so that you will be able to see that all waste has exited the tank.

You will know this is the case once the liquid running through it is totally clear of debris.

There are a few tricks to dumping your gray and black water tanks that make doing so easier.
  1. When parked at a campsite, make sure the black water tank is closed and the gray left open.
  2. Never completely fill any tank with liquid because doing so can cause serious damage.
  3. Before you dump, close the gray water tank and make sure to allow some liquids to go into it.
  4. Then, since you already will be hooked up to a sewer outlet, all you have to do is pull the handle on the sewer tank and allow the contents to empty.  
  5. If the connector does not show that the fluids are clear, fill the tank half way with water and empty it again.
  6. Keep doing this until the fluids are clear. 
  7. After doing that, open the gray water tank and empty it.  
(Emptying gray water second will clean any remnants of waste from the hose and make it more pleasant to handle when storing.)

Following this procedure, place an Enzyme product and 1 gallon of water in the tank to keep sludge from building up and eat away any debris that may have gotten stuck to the sides of the tank.

Deep Cleaning

When you start smelling sewer odors in your unit, it’s time to do a deep cleaning.

Here are the directions:
  1. Empty the waste water tank.
  2. Use your wand or built in back wash system to do a thorough cleansing of your tank.
  3. When finished, fill it 3/4 full with water.
  4. Add two cups of liquid bleach.
  5. Allow it  to sit in the tank for a maximum of 10 minutes.
  6. Drain.
  7. Perform another fill and drain.
  8. Continue to filling and draining this way until you see that there is no debris coming through the hose connector.
  9. When finished, empty the gray tank and add an enzyme product as per the above directions.
You should always do a deep cleaning before storing your coach so that the enzyme product will keep it from smelling.

Maintain Your Sewer Tank Properly

Although caring for your RV’s black water tank is not the most pleasant job in the world, it is undoubtedly one of the most important ones for you to do.

Clean, sanitized tanks help you to avoid problems, save you  money and make vacations more pleasant, so it’s a good idea to take care of them properly.