Composting Toilets home
Sun-Mar self contained toilets
centralized composting toilet systems
Sun-Mar options & accessories
Composting toilet Frequently Asked Questions (FAQs)
in PDF format
very informative (only 3 mg)
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Always insulate the floor underneath--retaining heat inside
the unit will help maintain efficiency of the composter. If you
install on a concrete floor, place a layer of foam insulation
or, better yet, a 3x6 insulated 2 x 4 wood platform underneath to
act as a thermal break. Be sure to install the unit on a flat
surface or slightly tilted towards the rear (never to the front)
– up to a 1/4-inch slope/drop.
Start the composting toilet bed with the enclosed peat moss
mixture and topsoil. A note on topsoil--it needs to be insect egg
free. Even if the topsoil is bagged and labeled insect free, we
would recommend sealing the dirt in an airtight black plastic
garbage bag, moistening the soil well and leaving it out in
direct sunlight for a couple days to bake (turning and shaking
As you use the composter, add one-quarter to
one-half-cup bulking material per bowel movement (enough to cover your
feces). Adding material regularly, so that the fecal matter
layers in with the bulking material, is key. It allows the
compost to “breath,” trapping air inside the pile. Place a small
wastebasket full of bulking material atop the unit to ensure it
is regularly added.
The Sun-Mar provided Compost Sure bulking material is a
mixture of sphagnum peat moss and hemp stalk. You can make your
own by combining pine planer shavings (sold as horse bedding at
ranch supply stores) and sphagnum peat moss. The typical ratio
is 60/40 peat moss to planar shavings. Many customers use
straight pine planer shavings, adding peat moss occasionally
when the compost is too dry--peat will allow it to better retain
more moisture. Do not use any cedar, redwood, or treated wood
shavings that would harm the compost health.
“Good” compost can take a couple weeks or more to get
a proper start--give it time to mature. If the compost is too
moist (pudding), not enough bulking material is being added and
oxygen cannot penetrate the pile. The compost may then go
septic and have an offensive odor. If this happens, add a gallon
or more of planer shavings to help it dry out and get air back
into the pile. Composting stops if the pile is allowed to dry
out completely--you then need to add peat moss and warm water.
Compost acceleration should be periodically added to ensure
optimal composting. Be certain to avoid getting accelerant
product in your eyes, and wash your hands thoroughly afterwards.
Let the material in the finishing drawer sit for at least a
week and become totally dehydrated before removal, and then
immediately back-tumble another drawerful. Keep the tumbler as
full as possible for maximum moisture retention and to ensure
carefree operation. Check with local health codes, but finished
compost can be added to an exterior compost pile (best), then
later tilled into ornamental plantings--or simply thrown in the
landfill or buried a foot underground. Take proper health
precautions when handling the finished compost (same rules apply
to septic tanks) and avoid direct contact.
Tumble the compost no more than three times a week. Excess
tumbling will actually hinder the composting action by
compacting the material and driving the air out. Be sure to
leave the compost tumbler bin in the full upright position after
Healthy composting toilet material is not an environment
favorable to insect life--becoming hot when tumbled three times
a week. But, if you have small flies inside your home now, they
will eventually find the composter later. You have to rid the
home of insects to ensure the composter starts out insect-free. Then, discourage insects from retuning by
spraying the air intake screen, under the seat and around the bowl
and cleaning any material stuck to the side of drum and then spraying
well. You can try natural pyrethrins or step up to a more
powerful aerosol spray and “bomb” the composter for a day or
two. Wrap in Saran wrap after spraying for best results.
Insects do not migrate great distances to set up shop in a
composter. Twenty feet from the nearest house plant is a big
“cross-country” holiday trip for a little white fly.
1- Keep infected houseplants away from your composter (all
houseplants seem to host a small colony in their root balls).
2- Avoid placement in underneath areas and open porches without
proper insect screening.
3- Spray the air intake areas with pesticide to discourage
We suggest installing surge protectors on any electrical
appliances--especially at sites remote from the power station and
those running on generator power. Preventing electrical power
surges from reaching electronic devices is key in some areas.
All 120 volt AC composters have an electric fan for constant
venting and a thermostat that controls the evaporation mat in
Always install the emergency overflow hose to a containment
vault/tank or a leach pit/drywell as per installation plans.
Even if the unit is capable of evaporating all liquid, you
should always install an emergency overflow--you never know.
Units ship with one side of the overflow hose plugged, the other
side open and ready to hook up.