Many people who are new to the RV world don’t have a clear idea about the purpose of the RV gray water tank. Holding tanks in your RV manage waste water demands in a transportable location, similar to how most residences have plumbing and sewer systems. Your RV’s plumbing and sewerage are handled by the fresh water tank, black water tank, and the RV gray water tank. The black and fresh water tank are utilized for fresh water and waste water from the toilet but many people are confused about what the gray water tank is used for. 

What Is a Gray Water Tank In An RV?

The holding tank into which your RV’s sink and indoor shower drain is known as an RV gray water tank. Except for toilet water, gray water refers to all utilized water in your RV. So, the gray tank collects water from the kitchen sink, bathroom sink, and indoor shower. When you clean your dishes in the kitchen sink or brush your teeth in the bathroom sink, the wastewater drains into the gray tank.

Washing machines and/or dishwashers are common in bigger RVs, and they normally drain into the gray tanks which may quickly fill the entire tank. So many RV washing machines come with warnings that they should only be used when connected to a sewer line at a campground or RV resort and the gray valve is open to prevent the RV gray water tank from being overfilled.

Average RV Gray Water Tank Capacity

Because the size of an RV holding tank often correlates to the size of the RV, determining an average RV gray water tank capacity is challenging. A Class A motorhome, for example, will have a bigger gray water tank than a Class B campervan. Usually a class A RV will have a gray water tank that can hold 40-65 gallons, a fifth-wheel would have around 95 gallon capacity gray water tank while most travel trailers have 25-45 gallons gray water tank.

How Often Should I Empty My Gray Water Tank?

As you go through the day-to-day experience of camping, your gray water tank will gradually fill up. However, because every camper is different, it’s difficult to predict how often you’ll need to dump your tanks. You might be able to go a week or more without depleting your gray water tank if you go alone and shower at the campsite facilities rather than in your RV. On the other hand, if you’re traveling with a family and everyone showers onboard every day, you’ll need to empty your gray water tanks more frequently. Most RVs feature a tank holding sensor that will notify you when your tanks are about to full up.

How To Dump The Waste From The Gray Water Tank

There are a few steps you can follow to make sure you properly dump the water from the gray tank without spilling it on the surrounding environment. 

  1. Connect one end of your RV sewage line to your RV outlet and the other end to the dump station inlet to dump your RV gray water tank. 
  2. To open the gray valve, pull the lever, which is similar to opening a little “door” or a valve gate.This operation permits the contents of the gray tank to flow into the sewage line, which then transports it to the dump/sewer station intake.
  3. Close the gray valve when all the water has been emptied from the tank, disconnect the sewage hose, and store it for the next time you need it.

How To Clean Your RV Gray Water Tank

There are a few things you can do to keep your RV’s gray water tank clean. You may begin even before the water is turned on by reducing the amount of food that is rinsed down the drain in your kitchen sink. Any food residue you can remove from your dishes before washing them means less will be rinsed down the drain, which will help keep the gray tank cleaner.

There are a few basic things you may do if you’re having odor issues with your gray water tank. When your gray tank contains around a half tank of water, purchase a dishwasher detergent and pour a cup of it into the galley sink before a day of traveling. As you drive, the detergent solution will splash around and then sit for a time. When you empty your gray water tank again, it will flush away any material you were able to free from the tank’s inside.

Best Gray Water Tank Dumping Practices

When it comes to your gray water tank, instead of opting for the “stealth” dumping option, be sure you dump it in specific city sewage connections. If you notice a stench emanating from your sink or shower drains, consider adding odor-controlling chemicals to your gray water tank.

It’s better to wait until your tank is completely full before dumping it, since this creates more pressure to flush out the tank and hose properly. You’ll also want to empty your black tank first so you can clean out the sewage pipe with your gray water. 

Taking good care of your gray water tank is very important if you want your trip to be fun and enjoyable without unwanted odors. Dumping and maintaining your tanks on time will ensure that your entire rig functions properly and your holding tanks aren’t overflowing making it impossible to camp at the spot you enjoy.