Monday, May 9, 2016

Basic composting toilets; Part 2-Composting media

In part one of this series (link) we covered the basic composting toilet container. This article will cover the various types of composting media.

It is possible to do combined urine and poo but most choose to separate the two. If you do combined, it will need more covering material and more frequent emptying of the bucket. Most also report that combined waste smells. I will cover various ways for a diverter in the next article.

Covering your "business" will aid in the composting process and also eliminate offending smells. There are three common types of composting media; sawdust or wood shavings, peat moss and coconut coir. Sawdust is the cheapest alternative and works very well. If you have a sawmill or woodshop nearby, you can typically get the material free by the truckload.

Peat moss is available at the garden store in various size bags. Price is usually depended on the size bag you purchase however the cost per cubic foot decreases quickly with larger bags. I have used peat moss for the past six months. It is simple, convenient and inexpensive. However, the harvesting of peat moss is detrimental to the environment. Thea Tapson will do a guest blog about the environmental impact of this composting media.

I have discontinue using peat moss because of the environmental problems. I now use coconut coir. Coir is the outer portion of coconut husks that is ground and compressed into a brick. The bricks are reconstituted by adding water.

The typical 10 pound coconut coir brick will make approximately three-five gallon buckets of material. For this reason, it is best to cut the brick and put a portion in a bucket before adding the water. If you try to add the entire brick to a 5 gallon bucket with water, the swelling of the coir will wedge into the bucket making it difficult to remove. Add water sparingly to the brick; for half a brick (about 5 pounds), I start with 2 gallons of water. Once the water is absorbed, I break up the pieces by hand and add more water, as needed. I typically make one five gallon container of coir and store the rest of the brick un-hydrated.

Procedure: Using composting media in a bucket toilet is relatively easy; granted not as easy as flushing a conventional toilet. When you complete your "job", scoop a couple cups of media over the "deposit. You only need to cover the material with about 1/4 to 1/2" of composting media. In a commercial composting toilet. the composting media will be contained within a vessel and a mixing rod will mix the media. This is a bit nicer because you do not need to scoop each time you do your "duty". Most of the commercial toilets also have a movable door that covers the media between potty breaks; this means you do not see into the composting vessel when you open the toilet. The trap door moves out of the way once you descend on the seat.

Bucket toilets will need to be dumped more frequently than commercial toilets. I typically dump my bucket toilet once a week. I have read that the commercial toilets can go a  month or longer between dumping.

The most frequent question about composting toilets is: Does it stink? No, once your business is covered, the composting toilet does not smell. The only smell you might sense is a slight earthy smell of the sawdust, peat moss or coconut coir.

Part three of this series will cover urine diverters. Stay tuned for more composting toilet excitement.


  1. Very nice. I just wanted to add that at least when employing worms to help break down the deposits, with a mostly one person use of a Natures Head, I only empty the solids every 3-4 months.

  2. Thanks Ariel; wow, only three-four times a year.