6 Best Composting Toilets for an RV, Off Grid Living, Or a Tiny House (2021 Reviews)

It’s hard to get honest composting toilet reviews. 

It’s awkward to ask your friend over dinner, “Hey man, tell me the truth. How’s your toilet?” 

Well, now you don’t have to. We’ve waded through mountains of sh*t and are ready to tell you which is the best composting toilet for you. We even found a composting toilet model that you can empty once a year! 

The Best 6 Composting Toilet Reviews

Don’t get squeamish now. We’re going to get down and dirty – we’ll talk about the ins and outs of the six best composting toilets of 2021. 

Here’s a handy dandy table to compare all of them:

PRODUCTNAMEDETAILS
Best Choice Best Choice Nature’s Head Self Contained Composting Toilet
  • Heavy-duty construction
  • Easy to use
  • Awkward to empty

Budget Pick Budget Pick Sun-Mar GTG Composting Toilet
  • Has vent fan
  • 2-gallon liquid waste receptacle
  • No lid for the liquid receptacle

Premium Pick Premium Pick BioLet 65e Composting Toilet
  • Fully automated
  • Active liquid control sensor
  • Expensive
Envirolet® MS10 Composting Toilet
  • Handles up to 8 people for vacation use
  • Dual fans and a heater ensure maximum evaporation
  • No urine separator
Separett Villa 9215 Composting Toilet
  • No need to empty urine jugs
  • Biodegradable bags
  • No agitation

Sun-Mar Excel Composting Toilet
  • Biodrum facilitates quick, odorless decomposition
  • Heater evaporates liquids
  • It needs a larger step up

Continue reading for our in-depth review of each composting toilet. At the end of our reviews, you’ll find our comprehensive yet easy-to-understand buying guide section.

1. Nature’s Head Self Contained Composting Toilet – Best Choice

Specifications

  • Max no. of users: 2

  • Waste capacity (solid/liquid): 5-6 / 2.5 gallons 
  • Emptying frequency: Once a month

Not that people are quick to talk about composting toilets, but when they do, it’s clear that Nature’s Head Composting toilet is a popular choice – check Nature’s Head Composting Toilet review on Amazon! And it’s our best composting toilet pick as well.

Moderately priced, the Nature’s Head Composting Toilet has everything you want from your composting toilet. Nature’s Head effortlessly separates your pee from your poop – which is key to keeping a composting toilet from reeking unpleasant smells (1). So, how does a Nature’s Head Composting toilet segregate solid and liquid waste? 

When you do a number two, move the handle, and it will open the poop chamber. If you have to pee, leave the trap door closed, and it will automatically divert the pee collection jug. 

Before attempting to expel your last night’s dinner, you’ll need to place a substrate like coconut coir or peat moss into the composting chamber of the Nature’s Head Toilet. After making a “deposit,” you turn a crank to agitate the materials together – the agitation helps start the composting process. Most composting toilets do not have this feature. 

The solid waste container only need to be emptied once a month, which is good because it can be awkward to empty it all the time. When disposing of toilet waste, you can put it in a plastic trash bag or add it to your compost bin. 

 If you are composting waste, make sure you are composting it for at least a year before adding it to your garden.

It’s easier to dispose of liquids – it’s a matter of emptying it down a drain or a sewer system, but you’ll do it more frequently. 

Overall, this Nature’s Head Toilet is the best waterless toilet. It’s reasonably priced, durable – it has stainless steel hardware, by the way!, and efficient in handling human waste. 

2. Sun-Mar GTG Composting Toilet – Budget Pick

Specifications

  • Max no. of users: NA

  • Waste capacity (solid/liquid): 6 / 1.85 gallons
  • Emptying frequency: NA

While the Sun-Mar GTG Composting Toilet may not feature all the bells and whistles of the other composting toilets, it is still a popular composting toilet if you are looking for a low-cost odor-free solution

As we mentioned before, the key to not stinking up your space is separating your pee from your poop. And this toilet does that. Plus, it has a fan that helps dry out your “solids” and waft any stinkiness away.

Unlike a traditional flush toilet, you’ll have to line the solid collection bin with a plastic bag. When it’s full, tie it up and dispose of it in a trash can. Emptying the urine collection jug is a bit tricky because it doesn’t have a lid. The solution is simple, though. Don’t let it get too full, and you should be good to go. 

This compact composting toilet looks stylish, unlike some of the other clunkier models. But don’t let its sleek look deceive you. It is made of the same rugged materials you would expect from Sun-Mar. 

Looking for the best composting toilet for rv? Tired of reading RV composting toilet reviews? You can use this Sun-Mar model as an RV composting toilet. 

3. BioLet 65e Composting Toilet – Premium Pick

Specifications

  • Max no. of users: 4

  • Waste capacity: NA
  • Emptying frequency: Once a year

If you are willing to take a huge chunk of money from your savings, the BioLet 65e Composting Toilet will do everything for you – except pooping, of course. 

This composting toilet has automatic everything. It mixes the compost for you- the only toilet on our list to do so. It also automatically detects the level of liquid. When the fluids are too high, it will turn on the heater to help with evaporation.

The BioLet is easy for guests and visitors to use as there aren’t any complicated instructions. 

You will need to empty the compost tray about once a year. But all you should see is a little bit of humus, which you can add right to your garden.

4. Envirolet® MS10 Composting Toilet

Specifications

  • Max no. of users: 8

  • Waste capacity: NA
  • Emptying frequency: NA

Do you have a vacation cabin that the whole family loves to visit together? Are you using the best solar power bank hooked to your phone so you can make late-night trips to the outhouse? 

If these situations sound familiar to you, the Envirolet MS10 Composting Toilet can accommodate a crowd!

This waterless toilet composting model does need AC power to run the fan and heater and accelerate the composting process. Installation-wise, it seems inconvenient, but this extra feature will minimize emptying the solid bin. The magic happens in the chamber below. 

When the waste tank is ful and it’s time to empty, you should see that the waste you deposited has broken down into a fraction of the size and is now ready to be used in your garden.

5. Separett Villa 9215 Composting Toilet

Specifications

  • Max no. of users: 4

  • Waste capacity: 6 gallons
  • Emptying frequency: Once a month

If the idea of emptying a jug of pee every few days isn’t appealing to you, check out the Separett Villa 915 Composting Toilet. This urine-diverting toilet may be one of the easiest out there and the best composting toilet for tiny house.

Similar to the Sun-Mar GTG, the Separett Villa doesn’t agitate solid waste. So, you will have to line the chamber with Separett compostable bags before making a deposit. 

When you sit down, it will automatically open the lid that keeps the chamber shielded from view. Once a month, you have to remove the bag and add it to your compost bin. In a year, it will be ready for your garden.

Watch this video to see how easy the Separett toilet is to empty:

If that wasn’t easy enough, the pee is even easier! It exits via a tube, and you can collect it, mix it with water and then give it to your plants. They will love you!

6. Sun-Mar Excel Composting Toilet

Specifications

  • Max no. of users: 3

  • Waste capacity: NA
  • Emptying frequency: 2-4 months

Unlike the budget-friendlier GTG model, the Sun-Mar Excel Composting Toilet has all the bells and whistles that you would expect from a Sun-Mar product. For a bit more money, you will get a much better toilet. The Excel features their patented Three Chamber System, which is what sets them apart. 

The first chamber is the BioDrum, which breaks down the solid waste. On the other, the urine goes to the second chamber for evaporation. And the final chamber is the finishing drawer where you remove your processed waste.

The BioDrum is the key component in the system. It regulates the humidity level to ensure the compost breaks down properly. All you need to do is occasionally turn the handle. 

Not too difficult. 

Like the energy-efficient space heater, this unit uses a heater and a fan. It does require power, which means it may not be the best composting toilet for off grid living. However, there is a kit available to convert it to 12 volts for solar. It also requires venting. 

Your Guide to Buying a Composting Toilet

I know. All this poop talk is overwhelmingly dull but don’t go yet. We still need to explain what all those fancy features mean for your family. 

Let’s start by explaining the…

Types of Composting Toilets  

Composting toilet systems are not new. Believe it or not, these environmentally friendly toilets were invented back in 1860. Since then, they’ve come a long way, and there is a lot of variety (2).

“In other words, a composting toilet can be self-contained or central, have single or multiple chamber tanks, be operated electrically, or manually, be waterbased, or waterless, separately collect urine, or collect urine and feces together through one pipe, and be installed in single and multistory buildings.”

Choosing which type of composting toilet will work for you and your family can be a bit tricky. So, here is what you have to know about them.  

a. Self-Contained Composting Toilet 

In self-contained products like Nature’s Head Toilets, the composting process occurs in the product. There are no separate tanks and no complicated tubes to connect (except maybe a vent pipe). 

They use a combination of fans, heat, and agitation to create the ideal environment to break down your solid waste quickly. They don’t require regular emptying and work well for vacation cabins. 

Enviorlet MS10 Composting Toilet is an example of a self-contained composting toilet.

They generally require power to run the heaters and fans, but you can find non electric composting toilet models. 

b. Centralized Composting Toilet

Centralized composting toilets are generally part of a more extensive household system, including more than one toilet. In these systems, the “deposits” feed into a central tank. This tank then composts all the waste from the toilets connected to the system. Now your composting is not happening in your toilet in your bathroom.

A centralized composting toilet is a good choice for an off-grid house with a family living there full time. 

c. Urine Diverting Composting Toilet

Urine diverting toilets like the Separett are popular with people living in RVs and tiny homes. These toilets separate the urine from the feces to minimize the smell (3). Most use some substrate material that you place in the solids chamber. 

Another advantage to separating urine is that plants love it (4).

“Urine also makes a good soil fertilizer because of its high nitrogen content.”

Some models have agitation; others don’t. There’s a lot of variation in the design of urine-diverting toilets, but they will be among the less expensive composting toilets. 

Installation Requirements 

Like installing the best small wood-burning stove, you’ll need to consider if fitting a composting toilet is a simple DIY project, or you’ll have to set aside money for a professional installation. 

Are you installing your toilet in a newly constructed house, or are you converting an existing space with a traditional toilet to a composting toilet? 

a display of composting toilets of different colors, sizes, and features
a display of composting toilets of different colors, sizes, and features

Plus, not all composting toilets are installed the same way. Different toilets have different features that limit fitment to your bathroom. 

Some composting toilets feature fans and vents that can require a certain skill level to install. For instance, if you’ve acquired a model that needs external ventilation, you’ll have to cut a hole in your wall. That might not be something you are prepared to do yourself.

Some may even require professional installation for other reasons. The Separett requires a tube to divert the liquid waste outside. In this case, you’ll have to hire a plumber. 

Many of these units do require some electricity to power them. So make sure that you have the appropriate plugs where you plan to install your toilet. 

Capacity And Maintenance  

Since a composting toilet collects liquid and solid waste in bins, tanks, or jugs, you should only get a unit with the right capacity to accommodate you and your family members. 

The Envirolet MS10 can accommodate up to 8 people for short periods of use, which is excellent if you have a heavily trafficked vacation home but might be overkill if you live alone in a tiny home.

When thinking about capacity, don’t forget to factor in how often you want to be emptying your toilet. 

Greater capacity and less frequent use mean less frequent emptying.

If you want to reduce the emptying frequency, look for a larger capacity. That goes for liquid waste as much as solid waste – you will be surprised at how much urine you expel daily.

Footprint 

When considering the size of your composting toilet, make sure you consider how much floor space you will need not just to use it but also to empty it.

Some toilets, like the BioLet 65e, have a drawer that opens out. You want to leave enough room in your bathroom for convenience. 

Also, you should think about how frequently you will be using the space. If you install your toilet in a vacation home, you might not mind if the area is a little cramped. On the other hand, if you will be using it daily, you might want to give yourself a little wiggle room to be more comfortable.

FAQs

Yes, composting toilets are good because they help conserve water and minimize waste. Plus, they are an excellent choice for areas with limited access to water. Some types of composting toilets will work better than others in certain conditions.

Ensure you carefully consider how many people will be using your toilet and how often they will use it. Then think about how often you want to be emptying your toilet. These factors will help make sure the toilet you get works well for you.

No, surprisingly enough, composting toilets do not smell bad. A key to minimizing smell is to keep out the liquids. Whether you separate them or evaporate them, getting rid of fluids will help keep your compost toilet from smelling bad.

Now it may smell-exact I won’t say it won’t smell. But most people will describe it as more of a rich earthy smell. Not unpleasant. Certainly distinct. But not the bad smell you would be expecting to get from a composting toilet.

Yes, you can put toilet paper in a composting toilet. The same process that composts your waste will compost the toilet paper. 

That being said, you should be conscious of how much toilet paper you put in the solid chamber. Toilet paper can fill the solid container fast, meaning you have to empty it more often. An easy solution is to put only your poopy paper in the toilet and throw other tissues in the bin. 

Also, you should never put anything besides toilet paper in your composting toilet. No baby wipes, no feminine hygiene products. Nothing.

How you empty a composting toilet is different depending on which composting toilet you have. With self-contained composting toilets, you generally open a tray to remove the processed compost. 

Urine diverting toilets have more variation. Generally, you have to lift the toilet seat to access the solids chamber. From there, the process will vary depending on which model you have. Some toilets use biodegradable bags that you simply add to your compost bin. Other the process is more complicated.

No, you do not flush a composting toilet. These toilets are what are called dry toilets. Unlike a traditional toilet, you don’t need water to flush down solid and liquid waste; your deposit simply uses gravity to fall into the chamber below.

You may want to keep a spray bottle on hand to clean up any messes if your aim isn’t so accurate.

  1. Composting Toilets: How Your Waste Becomes Black Gold.Retrieved from: https://earth911.com/eco-tech/how-does-a-composting-toilet-work/
  2. Composting toilets as a sustainable alternative to urban sanitation. Retrieved from: https://www.researchgate.net/publication/258852961_Composting_toilets_as_a_sustainable_alternative_to_urban_sanitation_-_A_review
  3. Urine-Diverting Dry Toilet (UDDT). Retrieved from: https://sswm.info/sswm-solutions-bop-markets/affordable-wash-services-and-products/affordable-technologies-sanitation/urine-diverting-dry-toilet
  4. Inside the Controversial World of Composting Toilets- Nala Rogers. Retrieved From: https://www.insidescience.org/news/inside-controversial-world-composting-toilets

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