A composting toilet has a lot of useful and awesome features (primarily the 20,000 or so L of water it saves us per year), but it does have to be actively managed. In theory, the six chambers should fill up over a year – so every 2 months you rotate the composting compartment to put a new, empty chamber under the toilet, and after a year you empty the chamber you started with (which, by then, will be full of harmless compost). In practice, it’s more like once a month than once every 2 months that we have to turn the composting compartment, which means that each chamber composts for only about 6 months.
The end product is therefore not 100% composted; it’s pretty good, but – especially at this time of year (when it’s cold) – I’m not confident that it’s ready to go on the garden. So we’ve added an extra step to the process: the composting chambers of the rotaloo are emptied into a secondary composter (a big wheelie bin, painted black and left in the sun to make sure it gets hot enough to kill any pathogens) to finish composting. After a month or two in that, the compost is ready to go – doesn’t smell of anything any more, and it’s just crumbly compost like anything you could buy from a garden centre.
Last weekend, we had the first lot of compost ready to go. It went around the date palms, dug in and buried, and it was really, actually harmless. You never know for sure until you try these things yourself, so I wasn’t sure, but .. I’ve had mushroom compost from Bunnings which has smelled worse and been nastier to work with. I’m super impressed. With any luck, so are the date palms.