How to Maintain Your Sun Mar Composting Toilet in 3 Simple Steps

Whether you've just purchased a new composting toilet system or you're still in the research stages before making an investment, one critical consideration is maintenance.  Proper ongoing maintenance of a compost toilet is critical to the system's performance and lifespan.  When correctly installed and properly maintained, a good composting toilet system will work perfectly.  When homeowners have problems with their systems, such issues can almost always be traced back to improper installation or maintenance.  In this article, we'll focus on Sun-Mar composting toilets, one of the older and better known manufacturers of professional composting toilet systems, and we'll explain the three easy steps to maintaining a Sun-Mar unit.

1. Add bulking material.  Just like a garden or backyard compost bin, composting toilets rely on the right balance of nitrogen and carbon (also sometimes called greens and browns) to decompose organic matter quickly and without odor.  Too much carbon (brown) will cause the composting process to slow down, whereas too much nitrogen (green) will make it smell bad.  In a composting toilet, all the human waste that goes in is the nitrogen, or green.  This means the homeowner must manually add the carbon, or the brown.  In the case of Sun-Mar waterless units, the recommended brown is a bulking material called Compost Sure, a mixture of peat moss and ground hemp stalk.  For Sun-Mar water flush systems, the appropriate bulking material is Compost Sure Blue, a similar mixture, just with a higher proportion of hemp stalk.  Adding the bulking material is an easy procedure that just involves dumping a cupful (or whatever the appropriate amount is for your Sun-Mar unit) right into the toilet itself.  To be sure you know exactly when and how much bulking material to add, always consult your Sun-Mar product manual and follow the instructions carefully.

2. Rotate the drum every 2-3 days.  Sun-Mar units operate on the principle of aerobic composting, which is a very fast and low odor method of decomposition.  Just as the name would suggest, aerobic composting requires air, or oxygenation of the compost itself.  With a Sun-Mar toilet, this process is very simple and does not require the homeowner to come into contact with or even view the contents of the toilet.  All that is required is to turn a handle on the outside of the toilet.  This handle will in turn rotate the drum inside the toilet, thus aerating the contents.  This step should be completed every 2-3 days while the toilet is in use.  Failure to do so will result in anaerobic compost that may begin to smell.

3. Empty some compost to the finishing drawer.  Every so often, some compost will need to be emptied from the toilet drum into the finishing drawer, a separate holding chamber in the bottom part of the unit.  Sun-Mar has designed their toilets to make this step incredibly easy, and again, the homeowner doesn't ever have to come into contact with the waste inside the unit.  One the front of every Sun-Mar system is a drum lock, or small knob.  Simply pull the knob out and turn the crank handle backward.  This will cause the inner drum to rotate around inside the toilet and automatically drop some compost from the drum into the finishing drawer.  This process will need to be completed about once or twice a year, depending on how often the toilet is used.

As you can see, maintenance of a composting toilet isn't difficult or complex.  It simply requires the ability to follow simple instructions and the diligence to perform those steps on a regular basis.  With the proper ongoing maintenance, you will enjoy years on continued use from your Sun-Mar system.