One part of a RV that newbies don’t like to think about is their holding tanks. I’ll admit that it was a little nasty thinking about our waste sloshing around beneath us, and it took a full month on the road and a case of the stomach flu to make us start dropping solids down the black-water tank. But these systems are some of the most important when you travel fulltime.

There are a lot of things to remember with your black-water tank – always add water after dumping so you don’t get a dry, caked on mess clogging your tank, use easily degradable –septic safe- toilet paper, and never throw anything down there like sanitary pads. After mastering these basics, the main thing to keep in mind with your holding tanks is odor control. Sure the safe handling of waste and water is important, but nothing will ruin a camping trip quicker than an overpowering smell coming from your tanks. All these tips will help you keep your tanks in good shape and the smells from taking over your rig.


Your rig should have three tanks; fresh water for all your water needs when you aren’t hooked up to city water, grey for the sink and shower water, and black for your toilet. Hopefully your rig also has a separate valve for each tank.


Before you leave the lot after buying your rig, you should have a dump hose and a water hose. Many dealers will throw this in when you are buying a new rig. We like the Rhino dump hose because it doesn’t deteriorate in the sun as fast as some other brands. We typically carry a 15 foot dump hose and a collapsible hose support to aid in dumping. There are longer hoses, but most FHU campsites have the hook-up right there.

When we were full-timing we carried two water hoses – one for drinking water and one for tank cleaning. When you dump you will want to flush your dump hose from time to time, and to be on the safe side you should not use the same hose that provides your drinking water.


You can buy a variety of chemical treatments at any camping store. We like the bio-degradable drop-in packets. There are also fluids and powders you can add to your tank. Whichever you choose, you should use something every time you dump and refill your tank. There are also additives you can add to your tanks in case they start to smell.

Some people recommend dumping chlorine bleach into the tanks. This is not something we advise because it will kill all the good bacteria that are breaking down your waste in the tanks.


No matter what chemicals and tank flushers you use or how often you dump, eventually you will need to clean your tanks. One method is to spray water into your black tank using a special wand attachment. You can do this from the top, spraying water down the toilet, or from the bottom, using a special nozzle on your dump hose to force water up the tank. Some RVs also come equipped with a tankspray.

Frankly this method never worked that well for us. The best method we have found for cleaning our tanks involves a warm day of driving and six bags of ice. First, do your last dump before breaking camp and add water to your tank. Then add at least six 10 lb. bags of ice to your tank. Head on out and do your day of driving. As you go the ice will slosh around the tank knocking off anything clinging to your walls. Once you make camp that night, dump again and your tank should be much cleaner than when you started.


Now that you got your supplies, you are ready to dump. This is basically the same process if you are dumping at your site or at a dump station*. When handling your dump hose, we advise using disposable gloves, or at least have Purell close at hand.

Hook up your dump hose to your rig and then fit the other end into the dumping site. NEVER dump without being hooked up to a proper sewage receptacle. When we’re in a spot for more than a few days, we’ll usually hook up our dump hose and leave the grey water tank open so we can shower and wash dishes at our leisure. When you are getting close to needing to dump your black tank, shut the grey tank and build up at least a half of tank of water in there.

When you are ready to dump, double check that your dump hose is still properly attached at both ends. First open up your black tank valve and let that drain out – you will hear the water flowing. If you aren’t using a support, when it sounds like the water has stopped running, lift the hose – starting closest to your rig – and move the water down to the dump end. If your rig has a tankspray, you can hook up a hose to the city water and flush your tank now. You don’t have to do this every time, but it helps keep things clean. Next close the black tank valve. Then open your grey tank valve and let that wash through your hose to rinse it off.

If you are breaking camp or at a dump station you will want to unhook your dump hose. When you unhook, ALWAYS start with the end from your RV and lift the hose to make sure all the liquids drain into the dump site. If you want to rinse your dump hose, do not put it directly under the water tap – hook up a water hose (preferably not your drinking hose) and use that to flush the other one out.

Once you store your hoses you are all set. Good job!

*Every RV is different, so please read your manual for directions specific to your make and model.