Preventative RV maintenance is something we all have to do, and some parts are less fun than others – like cleaning your RV’s black and grey water tanks. Although cleaning these tanks can seem like a tough process, there are plenty of easy and straightforward methods. One of these options is to use dawn dish soap in RV black tanks.
We’ll go through the benefits of cleaning your black tank with Dawn dish soap along with how to do it and some other options you can consider in today’s guide.
Benefits Of Using Dawn Dish Soap In RV Black Tanks
Dawn dish soap is the leading brand of dish soap for a reason – it’s great for cleaning, but also has tons of other uses like lifting stains, cleaning drains, deterring pests, and is even tough enough to use in oil spills!
Cleaning your RV water tanks properly is extremely important, so you’ll want to make sure that Dawn is safe to use in your RV water tanks before going full steam ahead.
Here are some key benefits of cleaning your RV black tanks with Dawn dish soap.
Easy To Find
Because Dawn soap is so popular, it’s easily found at grocery stores, Wal-Mart, Target, Amazon, and even some gas stations and convenience stores have it stocked on their shelves.
The fact that it’s so readily available beats out other specialized solutions that you could be waiting days or longer to get shipped to you, which is a big plus.
Affordable
Dawn dish soap is super affordable and much cheaper than other fancy cleaners that are made specifically for cleaning your RV’s black water tank.
RV ownership and maintenance is expensive enough as it is, so it’s nice to save money where you can.
Environmentally Friendly
Dawn is a “green” aka eco-friendly soap that can be broken down by bacteria, making it safe and biodegradable and way less harsh on nature than other engineered RV tank cleaning solutions available on the market.
It’s Non-Corrosive
Dawn dish soap’s formula is also extremely gentle while maintaining effectiveness.
It’s great at eliminating odors, breaking down grease, and loosening blockages, but you never have to worry about it eating away at your RV’s water tank.
Other cleaners like bleach are corrosive in nature and can also damage other parts around your tank, which is no good.
Dawn is safe to use in your RV tank and won’t damage the rest of your RV’s plumbing system.
How To Use Dawn Dish Soap In Your RV Black Tank
You’ll want to clean your RV’s grey and black tanks with Dawn soap at least twice a year (assuming semi-regular use).
Increase this frequency if you are a full-time RVer or if you have a large group or family using your RV during trips.
Here’s how to clean your RV’s black and grey tanks using Dawn dish soap:
Step 1: Empty Your Black And Grey Water Tanks
You should frequently empty these tanks so that blockages and odors don’t start to make trouble for you, aiming to empty them when they’re about ⅔ full.
Connect the sewer hose and emptying the tanks at an approved dump site, dumping the black tank first, then the grey tank.
Step 2: Clean Out The Tanks
Remove any buildup by using a flush valve, tank rinser, or macerator – this will help prevent any future blockages from building up.
Step 3: Add Water
You’ll want to add 4-5 quarts (1-1.25 gallons) of fresh water to your tanks, as the tanks need some water in them to operate.
Don’t leave your tanks dry!
Step 4: Add Dawn Dish Soap To Your RV Tanks
Add ¼ to ⅓ cup of Dawn dish soap to your tanks and you’re ready to go.
Optional: Use The Geo Method
The geo method is a term an RVer made up in the 1980s for a custom solution many RVers use to clean their grey and black RV water tanks.
You’ll need the following ingredients to make the solution used in the Geo method:
- 2 Capfuls Of Liquid Water Softener (everyone swears by Calgon brand specifically)
- 1 Cup of Dawn dish soap
- 1 Scoop Of Borax Powder (this is optional, but be sure to add a gallon of hot water first or dilute it if using Borax)
You can flush all these down your RV toilet to get them right in the black tank after adding a little water.
The geo method will cut down on the smells and keep your sensors clean and reading accurately.
Alternate Option: Add Dawn Dish Soap To A Full RV Black Tank
Some RVers have also sworn by adding the Dawn soap to a full (or nearly full) black tank as well.
In this case, they poured a full cup of Dawn in there and said the drainage process went very smooth for them next time they emptied it.
Other DIY RV Black Tank Cleaner Options
There’s other options available to you besides using dawn dish soap in RV black tanks.
Here’s a few to give a try and see what works best for you:
Laundry Detergent
Laundry detergent is easily available (most of us have it at home) and is gentle and cuts down on smells, giving many of the same benefits as when you use dawn in RV black tanks.
Fabric Softener
Similar to laundry detergent, fabric softener is great at cutting odors and breaking down buildups in tanks.
Ice Cubes
Another method of “cleaning” your RV’s black tank involves dumping between a few cups and up to a half-bag of ice in your black tank (in addition to or separate from any other cleaners or ingredients) and driving the camper around.
The ice will slosh around in the tank, helping to break up and “scrub” the tank as the cubes move around in transit.
Once the ice has melted you can drain the tank and it will be cleaner than before.
Many RVers argue whether this is effective or not, but it’s so cheap and easy to try that it’s certainly not going to hurt anything.
Yeast
Kitchen yeast is an active culture that softens and eats away at the waste and bacteria in your tank.
Most RVers mix it with hydrogen peroxide to enhance the effect and help it work faster.
Pine-Sol
Some campers rave that a single capful of Pine-Sol will help cut down on smells and reduce blockages in the tanks.
Citric Acid
Citric acid is natural, gentle, and works well at killing odors and deposits in your RV’s tanks.
You can combine it with baking soda and Borax to enhance its effects.
Plain Old Water
Some folks swear by flushing out your tanks very well after each emptying with tons of water and that works just fine for them.
Of course, if you have any issues with smells or buildup you should consider one of the other solutions we’ve outlined in this guide.
If You Still Notice Smells After You Use Dawn Dish Soap In Your RV Black Tank
If you try any of the methods we covered and you still are getting smells in your RV when emptying your tanks, you’ll want try one of the following options:
Fill The Tank And Dump Again
Simply fill the tank completely with water, then drain the tank again.
This will help get any debris caught on the walls or elsewhere in your tank loosened and will “flush” them out on the second full rinse dump.
Try Happy Campers RV Holding Tank Treatment
Happy Campers RV holding tank treatment is awesome and works very well for killing odors and works great in hot and cold temperatures, and also breaks down most household bathroom tissues too!
1 scoop of this stuff will treat a 40 gallon RV black water tank.
Can You Use Dawn Dish Soap In RV Black Tanks? Conclusion
So as we covered in this guide, Dawn dish soap is an easy, safe, affordable, and effective for use in your RV’s grey and black water tanks.
There are plenty of other affordable options too, so try a few out and see which works best for you.
Let the rest of us know about your experience as well as any other tips or tricks in the comments below.
If you’re a DIY-er, check out our other guides to how to fix an RV toilet not holding water, our guide to RV window glazing bead replacement, how to fix an RV microwave not working, what to do when your RV heater blows cold air, and how to solve an RV air conditioner freeze up while you’re here.
