Theory Of Composting Toilets; Moisture; Temperature; Aeration - Biolet 20 Deluxe Owner's Manual

Adjust your thermostat to the appropriate setting using the chart below. (This may not be your ideal setting. See
7.
"Use and Care", "Adjusting the Thermostat" below)
Toilet used by
1 person
2 people
3 – 4 people
Your BioLet is now ready to use.
8.

Theory of composting toilets

There are 4 factors that affect the efficiency of a composting toilet:

Moisture

In optimum conditions, the composting material has the consistency of a well-wrung sponge – about 45% to 70%
moisture. When below 45%, there is not sufficient moisture for the microorganisms to function, and above 70%,
saturated conditions begin to develop, and oxygen depletion becomes a limiting factor.
Maintaining moisture
In your BioLet 10 Standard or 20 Deluxe the moisture content is maintained by proper ventilation, addition of
proper mulch, frequent mixing of the compost and adjustment of the thermostat.

Temperature

The typical temperature range for most composting toilets is 68°F to 112°F. Lower temperatures result in a moldering
process that takes a significantly longer period of time to compost and therefore requires a much larger composting
chamber.
Maintaining temperature
Since there is a constant flow of air through your toilet the ambient room temperature needs to be maintained
above 64°F during periods while the unit is in use. The toilet heater is unable to maintain sufficient heat to
evaporate the excess liquid and sustain the composting process when temperatures decrease below this level.
During periods of lower ambient temperatures (late autumn, early spring, and winter) you may find it necessary to
increase the thermostat to maintain the proper operating state of a moist, loamy material with no indication of
liquid. Conversely, you may find it necessary to decrease the thermostat during higher ambient temperatures (late
spring, summer, early autumn) to keep from drying out the material inside the toilet. (see "Adjusting the
thermostat, Things to watch" section below)

Aeration

The aerobic organisms responsible for the composting process require free atmospheric or molecular oxygen to
survive. Without oxygen, they will die and be replaced by anaerobic microorganisms that will slow the composting
process and generate odors. For composting toilets to work most effectively, the materials being composted should
be unsaturated with liquids, and have a loose texture to allow air to circulate freely within the pile.
Maintaining aeration
Although the fan in your BioLet 10 Standard or 20 Deluxe does help with the flow of air through your ventilation
pipe, it is designed primarily for circulating the air throughout the unit. Therefore, maximum aeration can be
achieved by: 1) Keeping the product inside the composting chamber in a loamy consistency. 2) Proper
installation of the ventilation pipe. Keep in mind that the addition of any angles in the vent pipe will reduce the
airflow. 3) Ensure a good flow of air to the bathroom from the living area. 4) Proper mixing of the product inside
the composting chamber (see "Using the mixer" on page 8).

Carbon to Nitrogen ratio (C:N)

Microorganisms require digestible carbon as an energy source for growth, and nitrogen and other nutrients for protein
synthesis. When measured on a dry weight basis, an optimum C:N ratio for aerobic bacteria is about 25:1.
Recommended setting
2
4
6
6