Cassette Toilet Vs Black Tank: Differences and Comparison

Written by

Paulk Webb


Freddie J. Hagopian

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cassette toilet vs black tank

A lot of preparations are necessary when you opt to stay in motorhomes and RVs. One of the things that you have to be mindful of is the call of nature. It comes any time and the two popular options to serve this need are the cassette toilet vs black tank.

Are you familiar with these? Cassette toilets are self-contained toilets that you can set in any section of your vehicle. On the other hand, a black tank or black water tank is made for carrying wastewater loaded in an RV or motorhome. You can add it to your vehicle if there’s an existing toilet system.

You may want to know more about them for the right choice. So, read on to be able to differentiate one from the other.

About Cassette Toilet


A cassette toilet is situated in the underbody of an RV. That’s why you can call it an RV cassette toilet. It’s a replacement for the traditional type of toilet that is used in RVs and motorhomes. Instead of a black tank, it has a portable tank underneath. This small tank has wheels so you can conveniently move it to the restroom or other dumping sites.

How does a cassette toilet work? It’s modeled after portable toilets or cartridge toilets, but it’s permanently attached to RVs. In terms of appearance, it’s like a normal toilet that you have at home. A good example of this is the Thetford cassette toilet. It allows you to respond to the call of nature and flush before leaving.

The differences between the cassette toilet and the normal one are the method of waste disposal and the size of the holding tank. These will be discussed in the following part.

  • Waste disposal with cassette toilet

Every cassette toilet has a sensor that notifies you once it reaches its capacity. Therefore, you can empty it at the right time. Although waste disposal needs to be done frequently, you’ll find it convenient. Where can you empty a cassette toilet? You can do it in a toilet or dumping station.

After clearing the bowl of waste, close the valve handle as preparation for emptying the tank. There should be a side access panel that you slide on cassette toilets for RVs. With a handle and rollers on the tank, you’ll just pull it behind you when going to dispose of the waste. If these features are not available on your cassette toilet, you should empty them when it’s not too heavy for you to carry.

Open the tank’s dump spout and place it on the toilet or hole to let go of the waste. When doing it in a toilet, you have to release the content twice or thrice to prevent overflows and clogs. You can find a portable cassette toilet with a pressure release button to free the waste just like SereneLife Outdoor Portable Toilet. But make sure not to bump the tank to not create a filthy mess.

When you’re finished with the waste disposal, you have to clean the tank with water by shaking it. You have to do it more than once and use tank cleaners like Caravan RV Sensor and Tank Claner and Camco TST Ultra-Concentrate Orange Scent RV Toilet Treatment.

  • Holding tank sizes

The holding tank of the cassette toilet is typically small to fit in RVs. There are variations but it’s usually five gallons. Hence, dumping should be done in three to five days.

About Black Tank


A black tank is usually found below the RV carriage. It can accommodate solid and liquid waste, as well as septic-safe toilet paper and biodegradable enzymatic products like Eco Smart Enzyme and Caravan Enzyme Formula. Keep in mind that wet wipes, diapers, tissues, Q-tips, and hygiene products are not welcome.

The toilet that works with the black tank is not similar to the toilet you have at home. You may find a lever or a pedal on the floor. Before using, it’s recommended to add a bit of water for a clean flush. When cleaning the bowl, it’s best to use Simple Green or mild cleanser like Diversey Mild Acid Toilet Bowl Cleaner to balance the enzymes in the tank. You have to avoid using bleach too.

  • Waste disposal with a black tank

When it comes to waste disposal with a black tank, you shouldn’t wait for it to be full. It’s best to get rid of the content when it’s half-full for the proper gravitational swoosh. Anyway, a black tank can have a capacity of 15 to 90 gallons.

  • How to drain the black water tank

You’ll need a sewer hose to attach to the tank valve when the valve cover is removed. Then, you have to connect the clear elbow with the sewer hole. You may need to screw it in or put a rock on it to prevent the line from getting dislodged. The hose attachments should be secured at all times. Then, open the valve to drain.

At this point, you can close the tank valve and fill it with water to have clear flushes. You’ll need help from a long hose from the bathroom in your RV. Thorough cleaning can be done in many ways. You can use a tank sensor cleaner, swivel head attachment, or a regular hose sprayer.

Cleaning a black tank is time-consuming compared to a regular toilet. But patience and good planning can get you through. If the black tank is not full when you empty it, you can pour in soapy water before draining.

Comparing Black Tank vs Cassette Toilet

Here are some factors that we can look at when comparing cassette toilets vs RVs black tanks.

  • Size

A black tank has a higher capacity than a cassette toilet. The sizes of black tanks range from 15 gallons to 90 gallons. There are variations with the size of cassette toilets too but the regular size is around 5 gallons. This factor will be judged based on your needs whether you’ll only use it on weekends or for a permanent abode.

As mentioned, you’ll settle for a black tank when there’s a toilet bowl installed inside your RV. If you don’t have it, you have to install a plumbing system, which is not required if you choose to have a cassette toilet.

  • Convenience

A camper toilet cassette is convenient to be carried around but the disadvantage is the frequency of waste disposal compared to the black tank with higher capacity. When emptying a black tank, you need to connect it to a sewer. In addition, it’s time-consuming to clean even though you don’t do it too often.

Again, each of them has pros and cons. The decision will be based on your needs, purpose, and frequency of use.

Flushing the Toilet

Size and convenience are the factors that you have to look at when comparing cassette toilet vs black tank. Owners of RVs and motorhomes have different preferences. It all depends on the purpose and the frequency of use. You’ll be the one to decide what works best for you.

Read more: Dual flush vs single flush toilet: what is the difference?

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