- Free Shipping On Orders Over $30 -
Save $5 On Your Next Order - Learn More Here

The Geo Method

January 10, 2019

Does The Geo Method Work On RV Black Water Holding Tanks What Are The Reviews Is It Safe To Use


The Geo Method is a homemade system for treating your holding tanks that many people swear by and is widely believed to be an effective and cheap treatment method. In this post, we are going to go over every inch of The Geo Method, how it works, pros and cons, how waste digestion and odor elimination fit into that picture, and our recommendations.


What is the Geo Method?

Created in the 80's by Charles Bruni, The Geo Method is a combination of powdered Calgon (water softener), laundry detergent (soap/surfactant), plenty of water and often bleach or chlorine (to attempt to control odor). It was created by Charles through his extensive experience as an RVer; to find a cheap way to maintain RV holding tanks. First, what does it mean to maintain a holding tank? Charles would argue that it is about keeping the tank sensors and walls and base clear of debris. We don't disagree with Charles, but we do believe that proper tank maintenance should go beyond just keeping the tank interior clean. More on that in a minute.

At the core of the The Geo Method system is a concept that you never see a dirty washing machine interior because soft water and detergent not only clean your clothes, but also the interior of the washing machine and The Geo Method applies this logic to RV holding tanks.

How does The Geo Method work?

The process of water softening (Calgon) makes it so that organic and inorganic waste (poop and toilet paper) alike don't stick to the walls of your holding tank. The addition of laundry detergent or dish soap is used to penetrate any solid waste that may still get stuck to the walls or sensors in your RV and help rinse it away. This makes The Geo Method, but mostly soft water, a decent solution for cleaning the interior walls and sensors in your RV black water holding tank. Here are the steps:

  1. Flush Holding Tanks
  2. Dissolve 2 Cups of Water Softener Into 1 Gallon of Warm Water - Do this for both gray and black tank.
  3. Add 1 Cup Laundry / Dish Detergent to Black Tank 
  4. Add Chlorine/Bleach as Needed To Control Odors




  • For many, The Geo Method works by rinsing away solid waste from the interior of an RV black tank leaving it free from residual debris
  • When used correctly, it can be an effective way to prevent misreading sensors
  • A safe alternative to treating your tank with caustic or dangerous chemicals
  • The ingredients are readily available and easy to find


  • The Geo Method does very little to break down solid waste (that can lead to clogs)
  • The Geo Method does nothing to reduce foul tank odors
  • It will kill the beneficial bacteria inside your tank that are actively working to eliminate odors and digest waste
  • If you are using it in conjunction with a holding tank treatment it may be negating the benefits of the treatment - essentially throwing your money down the drain
  • It isn't necessarily an effective treatment process for dry campers (boondockers)
  • It is actually quite expensive after you consider all of the costs


Let's dig into this a little deeper


Understanding water softeners and their effect on holding tanks

The process of water softening removes calcium and magnesium in water that can cling to your tank sensors, causing them to misread - which is a good thing. However, this process can also make the water uninhabitable for any bacteria inside your tank that assist in digesting the solid waste and can lead to clogs and backups. This is because the ingredients in Powdered Calgon cause a chemical reaction with hard water that raises the waters PH to levels that kill off good bacteria. The water softening process with Powdered Calgon also creates sodium bicarbonate (baking soda) as a byproduct of the chemical reaction with hard water. 

Many people don't fully grasp that bacteria and enzymes are a crucial element to maintaining clog and odor-free tanks. If you aren't familiar with this concept, you can learn more about how bacteria are a crucial element in reducing solid waste and reducing RV toilet odors. If you fully understand this concept, you can clearly see how The Geo Method would interfere with waste break down and odor reduction in your holding tank.

Will The Geo Method kill the beneficial bacteria in my tanks and cause problems?

A quick primer on bacteria: Anaerobic bacteria, which is already in your gut and is present in human waste (poop), is much more resilient to chemicals and may often survive treatment with the The Geo Method. At first glance this sounds great! Unfortunately, though anaerobes are helpful in digesting solid waste, they also release methane and hydrogen sulfide gas which make that all-too-familiar sewer smell.

Unfortunately, aerobic bacteria that DO effectively break down solid waste and eliminate odors by releasing carbon dioxide and oxygen (the kind you really want in your tank), will likely die off in the high ph environment created by Calgon.

Simply put, with The Geo Method you are reducing the chances your solid waste will get adequately digested. Furthermore, it is likely that if used as a regular treatment, you will actually increase the ability of anaerobic bacteria to create strong toilet odors.

Dry Camping

Anyone who boondocks or has issues keeping water in their tank will still continually deal with odors and clogs. The water in The Geo Method is the only thing keeping odors under control, and at that, water is nowhere near a foolproof solution. If you plan to use the The Geo Method while dry camping, here are your viable options for using water as an odor control:

1. Add a buffer of 5 gallons of water (or more) to your holding tank before you leave, this allows your water reserves to stay ahead of a possible poop pyramid.

2. Keep water in your RV Toilet to create a water barrier, like you would find in your home toilet. The water keeps odors from seeping up from your holding tank.

Even these steps can only do so much to reduce tank odors. When you're dry camping the odors WILL build up because as many dry campers know, even in the best case scenario, you can still get odors. Water softener and soap just can't cover all the bases.

Bleach and chlorine in your tank

As you now know, bacteria and enzymes are a crucial element for maintaining clog and odor free tanks. You have also learned that Calgon can kill the beneficial bacteria, which for people who use bacteria holding tank treatments, is a major detractor to The Geo Method. Another problem is adding bleach or chlorine to eliminate odors in your holding tank, as prescribed by The Geo Method. Bleach and chlorine are designed, specifically, to kill bacteria.

We won't go into this any further, as we have discussed this already at length. Needless to say, killing the bacteria in your tank is almost always a bad idea. Sure, it may eliminate some of the odors, but it is only a matter of time before you get a back-up or compacted tank.


Many people who choose to use the Geo Method are able to do so affordably. But based on what we have found, between Calgon and Tide laundry detergent, the ingredients come out to be roughly $3.68 per treatment. This doesn't account for added bleach or chlorine. To put that in perspective, our RV Digest-It Holding Tank Treatment is only $0.87 per treatment (or lower if you use the larger sizes). Though The Geo Method feels inexpensive at first glance, it is actually one of the most expensive ways to treat your tanks if you use it regularly!

Sign up and get regular discounts on your favorite RV necessities. Unique Camping + Marine Holding Tank Treatments
How Does Unique Camping + Marine Fit into the picture?

Unfortunately, the process of softening water can and often will damage bacteria due to the increased ph levels, so many of our products aren't a great option to use in conjunction with The Geo Method on a regular basis. For many, The Geo Method is very good at cleaning sensors and preventing waste build up on the inside of a holding tank so using the The Geo Method occasionally can be a good way to prevent sensor issues. Just know that if you are using bacteria / enzyme treatments to treat your tank you'll need to thoroughly rinse your tank after performing The Geo Method before you can resume using bacteria treatments.

It is important to understand that waste break down can become a monster of a problem very quickly and The Geo Method probably isn't the best all-around solution. 


In conclusion, The Geo Method is potentially a good solution for preventing sensor problems and it can successfully be used to ensure your tanks remain clean and free from residue, however, it is far from a complete solution to treating your RV holding tanks and may present many problems.

The Geo Method, in our opinion, is only one solution to a complex problem. Considering The Geo Method's inability to effectively breakdown solid waste, the complications that come with not having enough water to suppress odors while dry camping, the cost of the ingredients, and the inability of The Geo Method to eliminate odors make it hard for us to recommend this process as a regular tank treatment.

Of course, this is just our opinion - though well researched and thought-out. We would love to hear your thoughts on The Geo Method! Please email us and share your experience-with or thoughts-on The Geo Method. 


Have You Checked Us Out On Social Media?

Follow us on Social Media and get access to discounts, promotions, and savings that aren't available on our website or emails!

To get started, message us on Facebook and we will send you a $5 off coupon code - all you have to do is Like our page!

- Facebook - Instagram Pinterest -

Also in News

What Is A Fifth Wheel? - We explore the history, pros, cons, and cost of fifth wheels RVs.
What Is A Fifth Wheel?

November 12, 2019

Admittedly, there’s quite a lot of terminology and camping lingo in the RVing world, and, especially if you’re new to camping, it’s easy to become confused! Today we will be covering one of these commonly asked questions: What is a fifth-wheel?

Continue Reading

Learn how to effectively dump your holding tanks at home. Quick easy tips for Septic owners and homes on city sewer.
How To Dump Your Holding Tanks At Home

October 29, 2019

It’s a common question asked by RVers: can you dump your RV’s waste at home? The short answer is, yes, you can dump your RV’s waste at home, and there are several ways to do it. Indeed, many RVers have good reasons not to empty their tanks at dump stations, and if you’d rather do it yourself, we’re here to tell you how!

Continue Reading

How To De-Winterize Your RV. Pulling Your RV out of storage to prepare get ready for spring and summer camping. Unique Camping and Marine
How To De-Winterize Your RV

October 09, 2019

The cold, cozy days of winter have passed and the warmer weather is quickly approaching! You’re probably itching to get out and enjoy the sunshine, but how do you prepare your RV to get back outside? Learn how to de-winterize your RV so you can hit the road with ease!

Continue Reading