Sun-Mar composting toilets from Oasis Montana

Oasis Montana Inc.
Authorized Dealer for
Sun-Mar composting toilets

Call us!  406-777-4309
Fax: 406-777-4309
Home Page:

Sun-Mar composting toilet retail sales
Sun-Mar Composting Toilet Tips

Composting Toilets home

Sun-Mar self contained toilets

Sun-Mar "Centrex" centralized composting toilet systems

Sun-Mar options & accessories

Composting toilet

Composting toilet Frequently Asked Questions (FAQs)

in PDF format

very informative (only 3 mg)

Solar water pumping

Renewable energy products

Propane appliances

Energy efficient appliances

Click on any of the pictures through out the site for a larger view in a new window.

  • 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 to mix).


  • 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 tumbling.


  • 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 visitors.

  • 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 base.


  • 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.


Back to top of page
Downloadable Sun-Mar brochure
(PDF 3mg)

Copyright 2008 - 2017 Oasis Montana Inc