Cleaning Your RV Tanks – A Free Guide

Regular cleaning and maintenence of your RV tanks is an important part of RV ownership. Doing so will prevent blockages, buildup, and bacterial growth. Although it initially seems like a daunting task, it’s a really simple routine. In this guide, we share everything you need to know about cleaning and maintaining your RV tanks.

Before we get started, knowing how to dump your RV tanks is essential to the process of cleaning them. You can learn how to dump your RV tanks in our free guide Dumping Your Tanks.

Fresh Water Tank

Your fresh water tank is your onboard supply of water. Even though we should only ever be filling our fresh water tanks with clean, potable water, it’s still recommended that the fresh water tank be sanitized every 6 months to prevent bacterial growth. The most common way to sanitize your fresh water tank is to use a bleach water solution.

Cleaning Instructions

  1. You will first assess your RV fresh water tank holding capacity. This number can be found in your RV owner’s manual.
  2. Once you understand how many gallons your fresh water tank can hold, you’ll need to do some math. For every 15 gallons of capacity, you’ll want to use a 1/4 cup of bleach.
  3. This amount of bleach can be added to your fresh water tank via the gravity feed opening on the outside of your RV.
  4. Once you’ve added the bleach, you’ll now fill your fresh water tank by hooking up to a clean, potable water source.
  5. It’s a good idea to also sanitize the water lines in your RV at the same time. To pull some of the bleach water solution into your RV water lines, turn on your RV water pump. Then, one at a time, turn on each faucet inside your RV and let it run until you can smell the bleach water.
  6. This bleach water solution should sit in your fresh water tank and water lines for 8-12 hours. We like to do this overnight.
  7. You’re now ready to empty your fully sanitized fresh water tank. This can be done by turning on your RV water pump, then all the faucets inside your RV, allowing them to drain the bleach water into your grey and black holding tanks.
  8. Once the fresh water tank is empty, you’ll want to fill it again from a clean, potable water source and repeat the process of emptying it. It’s not necessary to let the water sit before emptying for a rinse.
  9. Check to make sure you can no longer smell bleach coming from the faucets. You can repeat once more if necessary.
  10. That’s it- you’re ready to use your fresh water tank for another 6 months!

Grey Water Tank

Your grey water tank is where the waste water from your sinks and showers will collect. Cleaning your grey water tank may seem less important than cleaning your black water tank, but the buildup that accumulates from grey tank waste water can be equally troublesome. Buildup can cause bad odors, inaccurate sensor reads, and clogs. With some quick and easy, routine maintenance, you can avoid these problems.

Maintenance Instructions

To maintain your grey water tank, add an enzymatic formulated tank treatment like this one every 2 or 3 dumps to help break down the grease, soap scum, and food residue that can build up on the walls of your grey water tank. Be sure to always follow the instructions on the label.

If you RV often enough or full-time, you may find that your grey water tank still needs the occasional deep clean. The easiest way to clean your grey water tank is to let your RV do most of the work!

Cleaning Instructions

  1. Fill your grey water tank about half way from a clean, potable water source.
  2. Add 1 cup of cleaning agent such as dishwashing liquid, laundry detergent, or water softener.
  3. Take your RV for a drive. Driving down the road will create a churning, sloshing motion that cleans the walls of your grey water tank, removing buildup and residue.
  4. For the best results, allow this solution to sit in your grey tank for a few hours before emptying.

Black Water Tank

Your black water tank is where the waste water from your toilet(s) will collect. In some RVs, the bathroom sink also drains into the black tank (you can refer to your RV owner’s manual to find out where your bathroom sink drains to). Much like you have to care for your toilet in a sticks-and-bricks house, you have to care for your RV black water tank. Although it may sound like an intimidating job, it’s quite simple!

Maintenance Instructions

To keep your black water tank in good, working condition, you should regularly use an enzymatic formulated tank treatment like this one. These types of tank treatments do a fantastic job at breaking down solids to prevent buildup, odors, and clogs between cleanings. For the best results, you’ll want to add a treatment to your black water tank each time you empty it. Be sure to always follow the instructions on the label.

In addition to these regular tank treatments, your black water tank should also be cleaned every month or so during regular use.

Cleaning Instructions

  1. Fill your black water tank about half way. It’s okay to use a non-potable water source for cleaning your black tank.
  2. Add 1 cup of cleaning agent such as dishwashing liquid, laundry detergent, or water softener.
  3. Take your RV for a drive. Driving down the road will create a churning, sloshing motion that cleans the walls of your black water tank, loosening buildup and sediment.
  4. For the best results, allow this solution to sit in your black tank for a few hours before emptying.

You may find that the buildup in your black water tank is a bit more stubborn, especially if there hasn’t been enough liquid inside to suspend the solids or the RV has been sitting in one place for an extended period of time. In these cases, you’ll need to do a deep clean.

Some RVs have built-in equipment for deep cleaning your tanks. By simply connecting a water hose to your built-in flush valve or tank rinser, buildup inside your tank is sprayed clean via a high pressure water stream. These systems have back-flow prevention to ensure waste water is contained within your tank until you’re ready to empty it.

If your RV does not have any built-in equipment for deep cleaning your tanks, you can add an inline system like this one which will do the same thing. You can also use a manual wand style rinser like this one. A wand style rinser connects to a hose on one end while the other is inserted into your black tank through the toilet. Just as the built-in and inline equipment, this wand sprays a high pressure stream of water to deep clean the interior walls of your tank.