Add a starter bed
Add a starter bed of carbon-rich bulking agent, slightly dampened with water.
Recommended:
- Pine wood shavings
- Hemp mulch/bedding
Not recommended:
- Fine sawdust
- Cypress, cedar, or eucalyptus
- Sugarcane mulch
Composting Toilets 101
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The Science of Composting Toilets
Our composting toilets use a natural aerobic process called thermophilic composting. Aerobic microorganisms (AKA microbes), including actinomycetes bacteria and fungi, break down the waste which produces heat and removes pathogens from the material. This process transforms waste into an odourless compost that is safe to handle. The length of time to compost depends on climate, chamber size, and composting conditions.
The four main factors affecting compost are:
01
Moisture
Too dry and the dehydrated microbes will hibernate and eventually perish. But too west and the conditions in the chamber become anaerobic killing the microbes. The perfect balance is 60% of moisture content by weight.
02
Oxygen
The incorporated ventilation is a simple fan that draws air through the composting chamber and disperses it externally. This encourages airflow for the oxygen-breathing microbes.
03
Carbon & Nitrogen
Microbes utilise both carbon and nitrogen to maintain a healthy lifestyle and to grow and reproduce, forming a strong culture. An ideal C:N ratio is 25:1 for a composting toilet, hence the use of a carbon-rich bulking agent to balance the naturally nitrogen-rich human waste.
04
Temperature
Microbes are thermophilic, meaning that they create heat and they prefer warmer conditions. This is why the composting process slows down and eventually halts when the chamber is cooler than 18 degrees Celsius (64 degrees Fahrenheit). Thankfully, the cold won't kill off the microbes but just cause a state of hibernation from which they can be woken up.
The Four Phases of Composting
1. Mesophilic
Mesophilic organisms, which thrive between 20 - 30 degrees Celsius (68 - 86 degrees Fahrenheit), are breaking down easily decomposable materials like toilet paper. The temperature increases as they proliferate.
2. Thermophilic
Thermophilic organisms grow and thrive between 45 - 70 degrees Celcius (104 - 158 degrees Fahrenheit). This is the rapid decomposition of complex organic materials, generating higher temperatures and killing off pathogens.
3. Cooling
When there's nothing left for the thermophilic organisms, the pile starts to cool and the mesophilic organisms return as the majority. Actinobacteria (and maybe some fungi or mould) will finish decomposing any remaining materials at a slower pace.
4. Curing
Naturally, when the pathogens are killed off and all the material is broken down, the culture of microbes starts to enter a stage of hibernation. The composting pile has matured into a humus, with an appearance and consistency similar to that of fresh potting mix.
Starting a Composting Toilet
Introduce microbes
After waiting for the equivalent of five days of usage, there will be enough material in the chamber to encourage microbial behaviour. This is the perfect time to introduce your composting microbes.
Mixing a Composting Toilet
A mixer helps to flatten the "cone" shape that naturally forms ensuring that all available space is being utilised, while also aerating the pile.
Warmer climate: Approximately once a fortnight is recommended for full-time usage.
Colder climate: While the composting process slows down in the cold, turn less often to avoid releasing too much heat from the thermophilic microbes.
Finished Compost
In ideal conditions, compost could be completed within a few months. But it does depend on the composting chamber and climate, it could take over 12 months for the compost pile to reach the curing phase.
How to tell if the compost pile is ready?
- Appear slightly crumbly and moist with an earthy smell, similar to a fresh potting mix.
- No longer producing heat and will have reduced in size by nearly half
- Organic material and toilet paper is no longer visible.
Where to use composted waste?
- You can bury the compost 10 cm below ground around fruit or nut trees, lawns, flower beds and shrubs
- Avoid contact with edibles such as vegetables and herbs
Using a Composting Toilet
After every liquid deposit, simply close the lid.
After every solid deposit:
Add a generous cup of your prefered bulking agent
Spray an enzyme-based cleaning agent around the bowl
Close the lid
Do not dispose of in the chamber:
Food waste
Chemical products or antibacterial cleaning agents
Sanitary products and nappies
Rotating Composting Chambers
One.
Cover the compost pile with a shallow layer of bulking agent.
Two.
Add a starter bed to the new chamber, and transfer its lid to the full chamber.
Three.
Connect the new chamber to the ventilation and drainage hoses.
Four.
Leave the full chamber in a sunny position to finish composting.
Urine Diversion
Diverting urine away from your composting toilet means it can be more efficient during colder conditions. Because the composting toilet can't rely on evaporation or drainage hoses to manage excess liquid.
It's important to remember that urine is a source of nitrogen-rich moisture; so if this is being taken away from a composting pile, the moisture and nitrogen may need to be replaced or the composting process will slow down. Which isn't a problem when the external climate is freezing temperatures and the composting process has already halted.