11/14/2010 - compost

Warning: the following blog is about our Airhead composting toilet and contains thinly veiled references to poop. If you are squeamish, please feel free to do something else while the grown-ups talk. I don't expect this subject to be of interest to everyone. Maybe some of you would like to review our very first trip instead.

Okay, the rest of you must be either very smart people who happen to be interested in just about everything or you're either a cruising sailor or a hope-to-be-soon cruising sailor who is contemplating purchasing a composting toilet. I have to preface this by saying that our experience with the Airhead is hardly exhaustive. For much more complete info, go to Eric & Sherrel's FAQ page and look at item #2 (that was just a coincidence so stop giggling).

The Airhead is set up so that there are two flow streams. The liquid portion is diverted to what is essentially a bucket with a cap while the, um, er, heavier items are diverted to the composting bucket situated handily right below the depositor. Toilet paper used during simple drying up procedures are deposited in a wastebasket but toilet paper used during the grosser clean-up jobs are deposited right along with the "night soil" (there's a euphemism I love) just like in a real toilet. I've read that many captains on boats with traditional heads do not allow toilet paper into the toilet. It has to be deposited in a wastebasket. To this I can only say "Eeeeeuw!" Granted, we use 1-ply and try to keep clean-up restricted to 3 runs of 3 sheets each followed by a 2-sheet wipe up of the bowl if needed. And, I'd probably be singing a different tune if I had a conventional head and it got plugged with too much toilet paper as they are frequently known to do. Fortunately, we don't have to deal with that.

Obviously the liquid portion of the toilet is a no-brainer. Pee until the bucket fills up, swap the full bucket with an empty one (you did buy a extra bucket didn't you?), and then dump the full one whenever and wherever is convenient and legal.

The composter is the part that requires a little bit of a learning curve. At least it did for us.

Before initial use, some sort of organic material is added to the bucket to help dry out the poo as well as add some of the humus and such that is needed to make what you have a bucket of compost rather than just a bucket of merde. The manufacturer originally used and recommended peat moss but by the time we got ours, he was using coconut fiber. The instructions call for soaking the fiber and then squeezing it out before putting it in the bucket. We did that the first time and it didn't turn out well. So this time we just added dry, fluffed-up coconut fiber. We also added more than they called for. The idea is that, once you've "done your business" you will turn the agitator handle 1/2 turn to allow the coconut fiber to cover the deposit. Well, when we used the amount the manufacturer suggested, the agitator couldn't even reach it. The poop, now stuck to the agitator just spun happily around above the fiber. Now we add enough so that the agitator can pick a little up from the very start.

So, we're on our second go-round with the composter. And I have to say, I think we figured it out. We dumped it tonight as it was getting pretty full and this was a convenient place to do it. I'm sure we could have gotten another week or two out of it but why bother if it's convenient now and may not be later.

We certainly don't use the composter every day as we are often in marinas or other places where shore facilities are available and convenient. We try to use shore facilities whenever possible. That said, tonight's load was made up of occasional uses while underway, four or five days while anchored at Port San Luis (daily use), a week while anchored at Angel Island (daily use), and occasional use while moored at Avalon Harbor for two weeks (probably 5 or 6 days' use). While that's not an incredible amount, like I said, I'm sure we could have gone another week or two before it had to be dumped.

One of the things I always wondered/worried about was: "What about the last deposit? If you dump the bucket the next day, it's hardly had time to compost."

True. And that might make dumping it kind of yucky although it would still be coated in coconut fiber and mixed with actual working compost. But still. I would have no qualms about tossing it, double-bagged, into a dumpster at that point. However, the way we've decided to handle it is pretty much how we handled it this time. When it looks like things are getting close to being ready to dump, we'll try to arrange to be somewhere where shore facilities are convenient for a week or so. Then we'll allow at least a week between the last deposit and the time that the batch is "harvested". That gives it some cooking time and lowers the yuck factor.

We kind of put off dumping the bucket tonight because our last experience was somewhat less than pleasant. However, tonight it wasn't even a little yucky. The contents were mostly a uniform dark brown and looked pretty much like damp bark dust. Well, except for the occasional piece of paper which breaks down a little slower. The odor was just like a working compost bin at home: kind of earthy. Not something you'd want to sit next to for a long time but it sure didn't smell like poop and wasn't at all unpleasant. Sure smelled better than the holding tank odor so prevalent on many boats and RVs.

There was a little bit of humus in the corners after dumping and we left it as seed for the next batch. Added some fluffed-up coconut fiber and we're good to go for another three or four weeks of daily use.

Okay, I'm done. You can call the others back in now. If you have any questions, please do not hesitate to ask. I'll be happy to do my best to answer them.