Remember that composting toilet? I’ve gotten a few questions about how our toilet works, and if we are still happy with our decision to replace the traditional marine head with a composting toilet. So far, I think we are happy with it, although that may be easy for me to say, because Capt. Mike is in charge of emptying the compost. If this post is TMI, I won’t be offended if you skip on to the next one……

Our Nature’s Head toilet functions by separating the liquid and solid waste, therefore keeping the odor down. It works by desiccating, or drying, the solid waste, killing bacteria and resulting in material that is the color and consistency of potting soil. A small fan circulates air through the head at all times, requiring very little battery power. We do need to remember to close the toilet vent each time we are under sail, to avoid getting ocean water in the vent, and we also unplug the fan so that it doesn’t overheat. These steps; unplugging the fan and closing the vent; and opening the vent and plugging in the fan are now part of our regular sailing checklist.

Number One:

We empty the urine bottle every one to two days. This is the only part of the process that does have an odor. Not in the bathroom itself (the Nature’s Head design works really well to contain the liquid waste and accompanying odors) but when we remove the bottle and it isn’t capped. In a marina, we empty the bottle into a toilet. When we are three nautical miles out to sea, we empty it overboard. In a crowded anchorage, we wait for a better opportunity to empty it. We have a second, spare bottle to let us go longer between emptying in those situations. We rinse out the bottle each time, and put a few drops of dish detergent in the empty bottle.

Oh, and then there’s the “pee tack”. Based on the direction that the toilet is installed, Sanitas must be flat or heeled over to port for the toilet to function correctly to separate liquid and solid waste. That means that if I need to use the head while we are underway and on the wrong tack, I need to raise my hand like a school girl to ask permission. Then Capt. Mike steers into the wind briefly to flatten Sanitas out so that I can go in comfort. It’s my least favorite thing about the composting head, honestly. What does Capt. Mike do if he needs to go while we are underway? I’ll leave it up to your imagination. It’s so much easier being a man!

Number Two:

We know that it is time to change the compost, when the handle used to stir the mixture becomes difficult to turn. That indicates that the coconut coir composting medium has done its job, and has absorbed all the moisture that it can hold. No sense pushing it past that point! We tend to have another bag of coconut rehydrated, crumbled, ready, and waiting. So far, we have used three bricks of coconut since we left St Pete in January. We have five blocks left in our stores which should be sufficient to last until we return to the states to wait out hurricane season. If we were continuing south through the Caribbean, we might have to get creative and use a different composting medium, such as peat moss, sawdust, or wood pellets. We prefer coconut because it stores in a very small space, is an extremely renewable resource, and is less likely to contain dormant insects or eggs than other forms of compost.

We simply take the lid off the toilet, and dump the solid waste into a garbage bag. I’ve included a few closeups. You’ll have to take my word for it, but I swear it does not stink! It smells like good garden dirt, but nothing worse than that. This part of the process would be a lot easier if we had more room to maneuver. We barely had the space to install the composting toilet in Sanitas’ head (and in fact, we had to remove some of the teak trim to make space) and there isn’t enough room to gracefully tilt the cover back like they show in the manual. Welcome to life on a small, narrow-beamed sailboat. Everything is just a little bit trickier than planned! We stored the used compost in a cockpit locker until the next opportunity to throw it away ashore.

We use this opportunity to give the head a thorough cleaning, using bleach water to disinfect the toilet base, floor, and sink. But we don’t bleach or even wash the compost compartment of the toilet. Nature’s Head says that good bacteria develop and remain in the residue in the corners of the container, helping the coconut compost medium work better next time, and helping to break down waste more quickly.

We’ve been lucky so far, and have had no issues with flies or gnats in the compost. We do add septic tank additives and a bacteria marketed to remove gnats. Whether they really do any good, I can’t tell, but why mess with success? The best part about this head, is that we can pretty much plan to do the regular maintenance when it is convenient for us, and don’t have to deal with unexpected failures or really messy leaks and breaks. And we never have to search for or pay for a pump out. I’m sure it’s not for everyone, but along with our solar power, and water maker, the composting head helps keep us independent and off the grid.