The Best RV Black And Gray Tank Treatment – Review

Last Updated on July 5, 2023

boondockers 15 off

Now I am going to talk about one of our “favorite” topics which are RV toilets, dumping, pooping, and smells. When you sit around the fire with other RVers, this topic will come up within 15 minutes of most conversations. It’s just something we always have to think about.

Nobody wants to RV around with a funky smell coming from the bathroom. It will definitely have a negative impact on your trip. It’s advised to use holding tank deodorizers so you can get rid of bad smells. There are several benefits to using holding tank deodorizers and cleaning treatments.

No more clogs: Over time, the septic tank will collect unmentionables and since there is no sewer line like you have in your home, the chemicals dissolve most of what is inside the tank. The best RV waste digester will clean out the largest and toughest blockages.

Save money: Having to deal with a clogged and oversaturated camper holding tank can lead to a large bill. When you use a high-quality compound treatment, you can make sure you aren’t left cleaning up more than you bargained for.

Clean the system: RV holding tank treatments are designed with special enzymes that clean out the system as well. There are even treatments that will clean level gauges, so the system can tell how full the tank is and alert you of any issues. To be honest, my dumb black water monitor always shows it is full, even when it is empty. After a good clean and flush though it works for about 5 minutes 🙂

Important Features of Holding Tank Treatment

When buying holding tank treatment, you will notice there are many to choose from. There are a few important features to keep in mind when looking for the right treatment for your RV.

Long-lasting Treatment: You should not need to worry about adding the treatment solution every day or week. The best RV holding tank treatment will make sure the black water tank is free of blockages and odors for at least a month. Monthly application is recommended to make sure the tank stays clean and works efficiently. I usually add a tablet after each dump and that works till the next dump.

Quantity: While it will not take an entire bottle to treat a holding tank, having multiple bottles or tablets on hand can save time and money in the long run. Since you should apply the treatment every month, knowing you have a few bottles on hand means you don’t have to worry about running out or forgetting to order more.

Additives: The chemicals in the treatment work to remove debris, break down waste, and dissolve toilet paper. The ingredients making up the composition can vary from product to product. Some may include detergents for added smells but they are not a permanent solution to clearing out the holding tank. Eventually, you will have to completely remove everything inside the tank, so be careful of additives that can weaken the solution.

Compatibility: Before you add a tablet or liquid to the tank, it’s important to note if the brand is compatible with your specific holding tank. Many are rated to handle tanks up to a certain size, so if you have a large space but a compound that works on smaller tanks, you may need more solutions.


Table could not be displayed.


caravan tabletsContents of Holding Tank Treatments

The chemicals in holding tank treatments all do pretty much the same thing. They deodorize the contents of the tank and break down solids making them easier to flush. They do go about it in different ways.

Bacterial treatments do it all. They break down waste, preventing it from clumping and clogging, and control odor, but they do start to lose their effectiveness at temperatures above about 85 degrees Fahrenheit.

Enzyme treatments use proteins to break down waste and prevent residue from forming inside the tank. They do not do anything to control odor, so most enzyme treatments are mixed with strong scents to cover up the tank’s natural smell.

Conventional chemicals have a long track record for reducing odors and dissolving contents. Although it is highly effective, the use of formaldehyde is controversial and in some areas, it’s prohibited. Mixing household cleaners in a holding tank that has been treated with RV-specific products can create dangerous chemical reactions.

Types of RV Holding Tank Treatment

There are different types of holding tank treatment options.

Tablets: Tablets dissolve in the toilet water to form tiny particles that will then run through to the septic tank. These particles flow through blocked areas to dissolve and break down the waste as well as any remaining toilet paper over a period of time. Ideally, you want to use tablets on a monthly basis.

Liquid: The liquid form of RV holding tank cleaner pours into the toilet and then flows down into the septic tank. It works faster than tablets because it moves much easier through waste inside the holding tank. The function of the liquid is the same as with tablets, dissolving waste, and toilet paper.

Powder: powder dissolves faster than tablets. It’s hard to know sometimes however how much powder you need since it depends on your holding tank size and the waste in it.

Holding Tank Treatment Recommendations

1. CARAVAN Extreme Odor Eliminator RV Holding Tank Treatment
Price: $24.99
20 Drop-InTablets


  • Chemical and fragrance-free
  • Eliminates odors in all climates
  • Easy to use
  • Rapid dissolving tablets
  • Dissolves waste solids and toilet paper

I’ve been using this lately. I put a tablet in a plastic cup, dissolve it in some water, and pour it down in my gray and black tank. It works. I don’t have any smell even when it is warmer outside.

RV Holding Tank Treatment Pricing

Depending on which type of holding tank treatment you get, the pricing will vary. With RV holding tank treatments, you will mainly pay for the size and type of the container. You can find anything around 24 ounces and smaller for between $10 and $20.

For more than $20, you will typically get larger bottles and containers that will provide more applications. It is best to buy the treatment in bulk to make sure you’ve got extra just in case you run out when you need it most on the road. This is something you definitely want to have on hand at all times. Otherwise, it is back to leaving the windows open all the time.

Dumping Your Tanks The Right Way

Dumping the holding tanks can be quick and easy, or an environmental disaster. Following these steps will make sure you get the job done right:

  • Start by inserting the downstream fitting on the 3-inch dump hose into the sewer port. Use a dump hose with a right-angle fitting to connect the sewer port and make sure it has threads or locking tabs. This will hold the hose secure and prevent leaks and odors. Make sure you have enough sewer hose length to reach the RV, connecting several hoses if you need to.
  • Make sure all the tank valves are closed before dumping the black tank.
  • Remove the cap to the outlet pipe on the RV and attach the sewer hose’s bayonet fitting to the end of the pipe. Once the sewer hose is securely in place, you can release the black-tank valve.
  • Once the black tank is empty, flush it with water to clean away contents that did not flow out naturally. You can do this in one of several ways.
  • A clean-out wand can be attached to a water hose designed for gray water and used to force water down through the toilet valve. You can also pour a bucket or two of water down the toilet to finish flushing the tank.
  • Another method is to use a tank flusher that’s built into the tank. Make sure the tank drain is open to prevent the tank from overfilling. Try and do this last step at least twice. Make sure to use a dedicated hose for this and not the freshwater hose.
  • Seasoned owners will fill the tank with fresh water at least once and drain again to make sure the contents are cleared out properly.
  • You can choose to keep the gray-tank valve open while hooked up. But it is preferred to allow the tank to fill before draining. This allows the tank to flush thoroughly when dumping, and the water can be used to flush the sewer hose after dumping the black tank. You must make sure that the black-tank valve is closed before dumping the gray tank.
  • Rinse off the area around the dump station. Add at least 3 or 4 gallons of water to the black tank and add a holding-tank treatment to break down solids and reduce odors.

RV Toilet Tips

  • Having a toilet in the RV is great. But it will not be great if it gets backed up. There are a few important tips to remember for keeping the RV toilet clean and sanitary.
  • When pouring water or tank treatment down the toilet, turn off the exhaust fan in the bathroom for a few moments so it doesn’t draw an odor from the black tank up into the living quarters.
  • Use only toilet paper made for RV and marine waste systems which are designed to break down easily.
  • Leave the black and gray tank drain valves closed in camp and watch the levels to drain them as needed. If the black tank is allowed to drain constantly, there won’t be enough water to keep solids flowing when you need to empty it, which can lead to buildup and even plugging of the system.
  • Always empty the black tank first, then the gray tank, which flushes out the sewer hose.

Last update on 2024-05-20 / Affiliate links / Images from Amazon Product Advertising API

Leave a Comment

Your email address will not be published. Required fields are marked *


No, thanks!