Did you think the only thing you could compost is your leftover vegetable scraps from last night’s dinner? Well you are in for a treat, because your human waste (yes, number two) can be composted as well!

This makes me very excited! I am a huge fan of digging a hole in the ground and doing my business to allow for the natural process of my waste returning to the earth where it belongs. However, if digging a hole isn’t your style, then a composting toilet may be right for you. Composting toilet systems are in!

When your waste is entirely composted, it makes for a great fertilizer for your garden or trees. The cycle of life is complete!

Seriously though, our sewer systems waste tons of water and makes us dependent on the system in which the man has built for us. Composting toilet systems are a great solution to become independent from this system and can be applied for RV, cabin, and marine usage.

Let’s get to the down and dirty about composting toilets!

How Do Composting Toilet Systems Work?

A composting toilet works in the same way that your garden composter works, except that the toilet uses a special system that utilizes chambers to enhance the decomposition process.

The toilet is built to utilize nature’s thermophilic reaction to breakdown all of the bad bacteria and viruses in the solid wastes that we produce.

This special process needs to have the right balance of moisture and oxygen to activate the microbes in order to breakdown the waste properly.

If this balance is achieved, the microbes create the heat needed to breakdown the materials that it feeds upon.

Once the microbes have finished digesting the waste, the leftover product is a rich, odor-free fertilizer that can be used to feed your plants.

Although each composting toilet system is built differently, there are three processes that must be completed for the toilet to finalize decomposition:

Eliminating moisture – Moisture control is a basic requirement of successful composting. Too much moisture and the pile will not have enough oxygen to activate the microbes. Not enough moisture and the microbes will not have a suitable environment to survive. A proper composting toilet will be able to drain excess moisture and keep the pile just right for the composting process to thrive.

Composting the solid waste – Maintaining heat within the pile is key for composting to take place. Although microbes will create their own heat naturally, given the right environment, some toilets have an electric heating component to help assist in the process and allows for quicker decomposition.

Finalized compost removal – Once the compost has been finalized, the rich organic soil will dump into a finishing drawer for removal. This finished product will be bad bacteria and virus free, is safe to handle, and does not smell bad. Having a finishing drawer allows for finished soil to be removed while the toilet is still composting added solids.

The most popular composting toilets have three chambers: a liquid capturing chamber, the solid waste tumbling chamber, and the finishing drawer.

The liquid capturing chamber will either be a removable cannister that you have to dump manually, as seen in the Nature’s Head design, or is an internal chamber that the toilet evaporates naturally, as seen in the Sun Mar design.

The composting chamber is a tumbling chamber that has a hand crank on the side. The chamber needs to be tumbled occasionally to keep the materials mixed and to oxygenate the microbes. Hand cranking the tumbling chamber every few days should do the trick.

The finishing drawer is a removable drawer that allows you to empty the compost without bothering the compost that is in production. As the tumbling chamber is rotated, the fine soil filters into the drawer. The compost within the finishing drawer dries out and is safe to remove and use.

How to use the Composting Toilet

The Sun Mar Composting toilet looks stylish in this bathroom

Placement and Installation – The main concern for placing your toilet is to make sure you have access to all chambers that need to be maintained or accessed. If your toilet comes with a vent and electric heater, make sure those components are not blocked in and have room for air circulation.

Most compostable toilets mount to the floor with brackets and screws. Installation is easy and can be done with the most basic of handyman skills.

Adding the base material – Before the first use, you need to add sphagnum peat moss or coconut coir into the base, per your manufacturer’s instructions. This is the “brown matter” that your toilet needs to activate the composting process, checkout my Guide to Composting to get an understanding of how the compost process works. Brown matter is the carbon base that your waste will have a biochemical reaction with to ignite the microbes’ thermophilic process.

Coconut coir – this is essentially the byproduct of coconut shells that is mulched into tiny pieces. It is then dried and compacted into wafers or bricks that you bring back to a full fluffiness with water. It is also used as a hydroponic growing medium.

Many prefer coconut coir as it is reusing a byproduct that was once considered to be waste. Think of all the products that use coconut, that makes for a lot of wasted husks! These once discarded husks now are finding a new life in gardens and composting toilets.

Coconut coir ready for processing!

Coconut coir is also easy and compact to store as it comes in convenient bricks. You do have to do a little work to amend the bricks with water, but it is an easy and quick process.

Sphagnum peat moss – This kind of moss contains no soils which has made it a popular choice for conditioning gardens and landscapes. The sphagnum variety of moss is highly valued by farmers and gardeners because it is practically 100% free of weeds, diseases, and insects. It also holds moisture well and provides lots of air space, which your composting microbes will love.

Sphagnum peat moss takes over 15 years to grow an inch!

Sphagnum peat moss is ready to go, out of the bag. No preparation is needed.

So why not choose sphagnum peat moss? There are some environmental concerns about the production and harvest of peat moss, which leaves many to opt for the coconut coir option.

According to the University of Vermont Plant and Soil Science, Sphagnum peat moss takes an astonishing 15 to 25 years to grow only a single inch! In addition, only 2% of the world is covered in peat moss, so there is not a lot to go around.

Many countries are trying to quash the use of peat moss entirely, as peatlands store an enormous amount of carbon dioxide. By destroying these lands, carbon dioxide gets released into the environment. Essentially, sphagnum peat moss is not an environmentally viable option for the health of the planet, which is counter-intuitive to having a composting toilet in the first place, right?

If you do decide to purchase sphagnum peat moss, make sure it is of the sphagnum variety, and not just peat moss.

Using your Composting Toilet – Once you have the toilet installed and the base added, simply use as a regular toilet. The toilet can handle many uses, about 60 – 80 number two uses. This can be an entire season without having to dump out the main chamber. For full time use, this is about a month.

Emptying the Compost Toilet – Depending on usage, about once a month, the main chamber needs to be removed and emptied. This is made into an easy process as the design of the toilet allows for easy removal of the chamber. Do not clean this chamber out, as any leftover wastes will inoculate the new pile with microbes. Don’t forget to add in your base material.

If your toilet has a removable liquid cannister, this will need to be dumped every few days, depending on how often it is used.

Note that not all models have to follow this step. Some models have a finishing drawer which does not require the emptying of the main chamber, as long as it does not get over-full.

Cleaning and Maintenance – The beauty of composting toilet systems are that they require minimal maintenance and cleanup. Waste drops directly into the chamber and does not streak the bowl, unlike traditional toilets that swirl water and waste around leaving a streaky mess. The chambers do not require cleaning as you want to keep your colony of healthy microbes intact between dumping.

You will want to periodically clean your lid, toilet seat and bowl. The main takeaway here is to NOT clean your toilet with any chemicals! This includes chemical wipes. These chemicals will kill off the natural microbes in your tank and could ruin the composting process.

Natural deodorizing enzyme products work well for cleaning your toilet.

And that about sums up the basics of composting toilets.

Composting Toilet FAQ:

In Conclusion

I hope you have found my composting toilet systems article useful and informative. I think composting toilets are awesome and are worth the extra expense for the longterm benefits. Sure, it will take a little bit of getting used to, but every step of becoming independent from the man is a step worth taking.

If you are interesting in more about composting, check out my composting techniques section for all sorts of composting knowledge and advice.

If you enjoyed my content, please share it with your friends!

Regina, owner of Maximum off Grid

Hi, I am Regina, the creator of Maximum Off Grid.

My goal is to teach you how to become more self-sufficient, no matter how small the change.

Please feel free to reach out to me with any questions or comments.

Have a great day!

Regina Ferrari


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