How to Clean an RV Black Water Tank

How to Clean an RV Black Water Tank

Explore America's Campgrounds

Cleaning your black water tank for your RV is important for the lifespan of your tank, personal hygiene and comfortable living while camping. There are not many steps for keeping your RV black water tank clean, but it’s important to be consistent in following them. Keeping up on proper maintenance is what will keep you from spending lots of money or many unpleasant hours on repairing your tank. You may be surprised how easy it is to maintain an RV black water tank and how easily accessible and affordable the products are.

Items you will need

  • Water softener

  • Bleach

  • Water hookup

  • Water

  • Rubber gloves

  • Cleaning wand

Step 1

If you own an RV or are renting one, you will most likely camp in an area that has full hookups. You’ll want to open your black water valve as soon as you hook up to your site. Do not do this. First install your hose to the hookup hole in the ground of your camping site but only open the gray water valve. Your gray water is waste water from the shower and sinks.

Step 2

Locate the monitoring panel in your RV to determine the levels of all three separate tanks (black, gray, potable). The monitoring panel will tell you how full your tanks are. Look for the black water gauge. Let your black water tank fill to 2/3 full before dumping. Now, solids will not build up on the sides of the tank because there is no water flow. If at the end of your camping trip the tank is not 2/3 full, fill the tank through the toilet with fresh water from the green sewer hose (the white hose is for fresh water only).

Step 3

Before dumping or opening your valve, add water softener to the tank. You can find water softener at the grocery store near the laundry detergent. Dissolve 2 cups of water softener to 1 gallon of hot water. Pour into the empty tank through the toilet. The water softener helps keep solids from sticking to the sides and will also help dislodge any leftover solids in the tank.

Step 4

After you’ve added the water softener, add 1 cup laundry detergent to 1 gallon of hot water and pour down the toilet. This keeps the tank clean.

Step 5

This step is optional but can help dislodge solid waste. Close valves to your tanks, unhook your hoses and drive around. This will help agitate the black water tank and dislodge any solid material.

Step 6

Before dumping your black water, close the gray water valve. Wear rubber gloves when handling black water tanks and hoses. Pull the black water valve and allow everything to empty out into the camp hookup site or dump station. Attach a rinse wand to the hose provided at camp and stick down the toilet. Turn the water pressure up to flush and rinse out the tank. Be sure someone is inside holding the wand in place in the toilet. This procedure will also flush out the sewer hose.

Step 7

Empty the gray water tank.


  • Before starting, review the RV manufacturer’s instruction manual for tank and water system cleaning information.


  • For added protection against solid waste backup, use the dissolving toilet paper sold at RV stores. When RV is parked and not in use, place stoppers in the sink and tub drains to allow the tanks to vent through the vent pipes outside instead of through the drains in the RV.