Buying guide for best composting toilets
![Michael]()
Written by
Michael
Updated May 2023
Composting toilets are an excellent way to “go green,” whether you’re an RV enthusiast, have a hunting cabin in the woods, or just want to live off the grid. Some people even install them in their homes to cut down on their water bill.
Rather than flushing and wasting water, solid waste is composted with things like tree bark, leaves, and wood shavings. The result is a product that can be used as fertilizer for your flower beds and shrubs. The liquid waste is usually collected separately and allowed to evaporate, or it is emptied on a regular basis.
Composting toilets require more maintenance and care than regular toilets to avoid odors, insects, and other health hazards. In addition, most require a 12-volt battery or 110-volt plug in order to power the ventilation fan that comes with them. The choices on composting toilets can be a bit overwhelming at first glance.
Key considerations
Size
Composting toilets are usually a bit larger than regular toilets because they need to have one or more composting or collecting chambers in them. The width of them isn’t much different than regular toilets, but the length from front to back is generally longer than a normal toilet. Take this into account when you’re planning on where it will be installed.
Measure your bathroom before comparing toilets, then have those dimensions close at hand comparing models.
Rough-in distance
The rough-in distance on a normal toilet is the distance from the wall behind the toilet to the bolts that secure it to the floor. Most rough-in distances are around 12 inches. You also need a rough-in distance on composting toilets, but for different reasons.
Many composting toilets have hinges on the back to allow access to the composting chamber beneath the seat. When you swing the top back on its hinges, there needs to be enough room behind the toilet for it to open up to a right angle. Otherwise, the composting chamber isn’t properly accessible for cleaning, emptying, and maintenance.
Before buying your composting toilet, measure the area where you’re going to install it and ensure there is plenty of room for opening the toilet.
Installation
These toilets are very simple to install, but it still takes about two to three hours to properly situate them, hook up the electricity for the fan, and run venting pipes.
The venting pipes require the most work, cutting, and fitting. This is the most time-consuming part of the installation.
Since it takes several hours to install a composting toilet, a user-friendly instruction manual is important.
Not all composting toilets come with the bulk material needed for composting. The toilet comes with the material or consumers will need to purchase it separately.
Many quality toilets are lightweight and made from high-gloss polypropylene or ABS plastic.
Because it’s important to clean a composting toilet on a regular basis, consider models that come with cleaning supplies or extra features (like a water gun) to make the cleaning experience easier.
The location of the crank handle (used to mix solid waste with the bulk material in the chamber) varies from one manufacturer to another. Some handles are on the side of the toilet, whereas others are enclosed in the front.
Some composting toilets can be used with composting bags. It's notable because it makes emptying it easier since you just throw the bag in the compost.
The size of each tank and how many flushes each tank can provide is notable. This gives consumers an idea how often they’d need to empty it. A toilet that is regularly used by a family should be emptied once a month.
The size of each composting toilet tends to be a bit longer than regular toilets.
Consider how each composting toilet collects liquid. Some toilets collect it in a bucket that you must empty. Others evaporate the liquid and vent it out through pipes or tubes. Some toilets offer both options so you don’t have to empty the bucket as often.
Consider both permanent and portable composting toilets and whether each toilet is mountable.
Features
Material
Composting toilets are manufactured to be lightweight, so they are generally made from high-gloss polypropylene or ABS plastic. Some parts (such as the crank handles and latches that hold them in place) are stainless steel or aluminum. The fan motor is metal, and some fan blades may be as well.
Colors
Composting toilets aren’t generally known for being available in designer colors. Most of them are white, off-white, shades of grey, or speckled granite.
Composting crank
The composting chamber needs to be rotated to mix the solid waste with the bulk materials in the chamber. This aerates the mixture and provides oxygen for the aerobic bacteria that do the work of breaking down the waste material. The process generates some warmth that tends to dry out parts of the materials. Mixing it on a regular basis is essential to maintaining just the right amount of moisture without it becoming either too dry or too wet.
The location of the crank handle varies from one manufacturer to another. Some have the handle on the side, but others have it enclosed in the front of the unit. The second method is a bit more aesthetically pleasing (and expensive), but that’s the only difference.
The average weight for composting toilets (out of the box) is around 30 pounds.
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Composting bulk material
Most composting toilets don’t come with the bulk material for the compost tank, although some come with a small amount in a separate bag. Read the description carefully to find if it does or if you have to purchase it separately.
Liquid waste
There are two methods of dealing with liquid waste in these toilets. One is simply to collect the liquid in a container and empty it on a regular basis. The other method involves evaporating the liquid and venting it out through vent pipes or tubes. Some composting toilets combine the two methods so you don’t have to empty the container quite as often.
Note that some liquid tanks don’t come with a cap, so be careful transporting them when you’re emptying them.
Did you know?
Composting toilets are fairly rugged. Most of them can support up to 350 pounds.
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Accessories
Toilet tissue: Thetford Aqua-Soft Toilet Tissue
Although a composting toilet can break down most toilet paper, this two-ply toilet paper from Thetford is specifically made for RV and marine use in composting toilets.
Cleaning vinegar: Heinz Cleaning Vinegar
There are potential spills with any toilet. Composting toilets need a little extra strength cleaning, and this cleaning vinegar from Heinz cleans and deodorizes.
Composting toilet prices
Inexpensive: For $50 to $100, you can find portable toilets that are intended for camping. These are plastic toilets that aren’t true composting toilets. They use plastic bags to collect the waste instead of composting it.
Mid-range: Toilets from $600 to $1,000 are true composting toilets that have two or more chambers to separate solid and liquid waste, as well as fans for assisting with evaporation and odor-control needs.
Expensive: From $1,000 to $2,000 are more sophisticated three-chamber composting toilets, with a sleek elegant look not found in some of the less expensive units.
Did you know?
Surprisingly, composting toilets have fewer odors than normal RV toilets. If there is any odor, it usually smells like fresh dirt or loam.
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Tips
- Every composting toilet is different but emptying the composting chamber should be done once a month (or more) for regular use of an entire family up to once every six months for one person.
- The finished composting material that comes out of a composting toilet doesn’t contain human waste or viruses.
- Keeping the lid down on the toilet helps control odors when it’s not in use.
- “Aim” is important when using a composting toilet because solids and liquids need to go into separate chambers.
FAQ
Q. Is the composted material safe and sanitary?
A. Yes. What comes out of a composting toilet isn’t human waste anymore. The aerobic bacteria in the tank completely break it down, removing the pathogens and viruses normally found in human waste. The finished material is not only safe, it is also easy to handle.
Q. What do I do with the composted material when I take it out of the toilet?
A. It is fertilizer. It can be used to fertilize the soil around any non-food plants, trees, or shrubs.
Q. Can the composted material be used in my yard?
A. Yes. Most people are too squeamish to try it but it is perfectly safe to use that way.
Q. Do composting toilets really work?
A. Yes. They require some extra effort on your part, but they work surprisingly well in addition to being eco-friendly.
