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Can You Use Dawn Dish Soap In RV Black Tanks?

Dawn dish soap at the store - Can you use Dawn dish soap in RV black tanks?

Can You Use Dawn Dish Soap In RV Black Tanks?

Keeping up with RV maintenance and cleaning is just part of RV life! One aspect that is necessary but not very glamorous is emptying and cleaning the black and grey water tanks. This can seem like a complex problem, but there are many products and solutions that can help make this a lot easier. One common remedy involves the use of Dawn dish soap in RV black tanks.

Whether it’s a store-bought cleaner or a homemade recipe, there are lots of ways to clean your black tanks and keep them functional. Below, we’ll explore some of the uses and benefits of Dawn dish soap as well as proper cleaning tank procedures and some other effective cleaners to consider.

Why use Dawn dish soap in RV black tanks?

Dawn dish soap is one of the most popular household cleaners and its uses are nearly limitless. Obviously, it can be used to clean dishes (it’s right in the name) but this soap can also be used as a pest remover, drain cleaner, stain remover, or just as an easy way to make a bubble mixture for kids.

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It’s important to properly clean your RV water tanks, so you’ll want to make sure that Dawn is a good choice before you start using it. Many people have incorporated it into their maintenance routines, and some of the benefits are listed below:


One of the best parts about using Dawn dish soap in RV black tanks is that it’s an environmentally-friendly soap. It doesn’t contain phosphates and can be broken down by bacteria. This means that it’s a safe and biodegradable soap to use, even if you’re cleaning/dumping your tank in a strict or natural environment.


Another great bonus is that Dawn dish soap is quite affordable! If you use high-end cleaners that are specifically engineered for tank cleaning, that price could add up fast. On the other hand, Dawn is cheap and it won’t make a dent in your wallet. In addition, you only need to use about 1 cup of this dish soap at a time, so the average large bottle will last you for multiple months or even years!


Dawn is also a gentle and non-corrosive soap. It’s effective at breaking down grease, eliminating odors, and softening blockages, but it won’t eat into the material of your tank. Other effective cleaners exist (such as bleach) but they can be harmful to your tank and the surrounding pieces. You can use Dawn with peace of mind and won’t have to worry about the long-term effects it will have on the integrity of your plumbing system.

Easy to buy in bulk

Finally, Dawn is widely available in stores and online, and easy to buy in large quantities. If you clean out your tank regularly, you may just want to get a huge container and work your way through it. If this is the case, Dawn is a fantastic option. You can find it at pretty much any grocery store and might even be able to find it in gas stations or small mini-marts along your journey. Loading up on large quantities is easy and affordable.

How to clean an RV black tank

Now we know that you can use Dawn dish soap in RV black tanks, but that knowledge won’t do you any good unless you follow proper tank-cleaning procedures. It’s important to do a deep clean of your water tanks at least twice a year, but you’ll probably want to do it even more frequently than that if you live in the RV full-time or have a large travel group.

Your black and grey water tanks should be dumped frequently so that odors and blockages don’t become a problem. Generally, the rule of thumb is that it’s time to empty them once they are about 2/3 full.

Many of us just don’t like to think about it until we have to, but cleaning out RV tanks is actually quite simple! Basically, all you need to do is:

  • Drain the tanks by connecting the sewer hose and emptying the contents into an approved dumping site. (It’s best to dump the black tank, then the grey tank so that the grey water can flush out more debris).
  • Clean out buildup by using a tank rinser, flush valve, or macerator. This will help prevent blockages in the future.
  • Add 4-5 quarts of fresh water to the tanks to provide a good base for future use. The system needs a certain amount of water to operate, so don’t leave it completely dry.
  • If you are doing a deep clean/ want to eliminate odors, you would add your cleaning solutions as the final step. This could include Dawn dish soap or another safe cleaner of your choice.

Another popular tank cleaning technique is known as the Geo method. For more details on this process, check out the video below.

Other cleaners for RV black tanks

Using Dawn dish soap in RV black tanks is certainly an effective method, but it’s not the only choice! There are lots of other DIY tank treatments that have been used over the years, and some of them might work better for you depending on your preference and the availability of certain products in your area.

While you can always use store-bought water treatments, there are lots of homemade tank cleaners you can try as well. Some of the most popular ones include:

  • Citric acid: This is a mild, naturally occurring acid that can break down build-ups and improve the smell of your holding tanks. It can be combined with Borax, water, and baking soda to strengthen its cleaning ability.
  • Fabric softener: Fabric softener is another good way to break down buildups in your tank and improve the smell. This is a mild and pleasant cleaner that has proven to be effective.
  • Yeast: Believe it or not, kitchen yeast is a good RV tank cleaner too! Yeast is an active culture that feeds off the bacteria and waste in a tank. It might take a few days to become effective, so some people combine it with hydrogen peroxide to make it stronger.
  • Water and more water: Surprisingly enough, some people get by just fine without using any kind of special add-in. As long as you use plenty of water to flush out your tanks, you may not need to add a chemical cleaner. However, if you’re having problems with blockages and smells, one of the previous options can be helpful.

Make sure you keep track of all your RV maintenance and repairs with an online tool such as RV LIFE Maintenance. Not only can you keep all of your documents in one place, but you’ll also receive timely reminders when maintenance is due to help you avoid costly repairs and potentially serious accidents.

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