"Composting" toilet questions

[SVRocinante]

Well, now you've gone and done it!

All this recent talk about composting heads vs flushing heads has got me thinking again; never a good thing.

Here's my situation - we are fulltime cruisers living aboard our Hanse 400e which happens to have a ridiculously small holding tank. If we're extra careful, we (2 adults) can make it last a week... not thrilled with that.

We have no other issues - at this time.
Our head does not smell & I have no trouble doing basic maintenance; I've replaced the joker valve twice & recently replaced the entire pump assembly (Jabsco).

I've looked into expanding the holding tank, but I've not found a viable/cost-effective solution, so I'm exploring the composting head for that sole reason - extended cruising time; theoretically 1 month for a couple.

Which brings us to my questions.

First, in your experience, how accurate is that estimate of 30 days for 2 adults before having to empty?

Secondly, in reading through the marketing material, the Air Head talks about "paper bowl liner for solid deposits" - looks to me like a large coffee filter, but in either case, is this the typical process?

If so, how well does it break up in the solids holding tank?
If not, what is your procedure?

As always, thank you for your time & input!

regards,

[CaptTom]

Someone with a composting/desiccating head will probably chime in.

But as one with no experience, it seems to me like you could accomplish the same thing by simply not using the head for #1, and collecting the urine separately. I hear this is what you do with with a composting/desiccating head anyway.

Only using the "regular" head for solids should give you a much longer time between pumpouts, and reduce calcification and the need to replace hoses and joker valves.

There are portable "camping" urinals sold for this purpose. Then there's the over-the-road trucker's trick of using a soda bottle. And for the gentlemen, there's always the lee rail.

[Mike OReilly]

Your reason for considering a composter was one of the top motivations for our switch. The others being: recovered storage space, simplicity and safety.

I’ve been using our Nature’s Head for must be six or seven years now. It remains one of the best upgrades we’ve done to our boat. We cruise full time, for part of each year. Two adults on board. When we leave our home dock we rarely tie to shore, so our head gets a lot of use.

We average around five weeks for the main tank. Four to six is what I usually say. There have been times when it has been less, but that’s usually due to some unusual event. And I’ve pushed it to beyond seven weeks a couple of times. Four to six is about right for us.

I know Air Head recommends the use of poop transfer carriers (coffee filters). Nature’s Head does not, and we don’t use any. I’m not sure why the difference. I’ve never used an AH, but my research and info tells me they are pretty much the same thing. Perhaps the access hole is smaller? Not sure…

The solids in our NH gets churned into the bedding material. I do find the NH churn sometimes compacts the bedding material into the lower corners. I use a small garden trowel to break this up (usually only once per cycle).

The vent causes the material to dehydrate, which is why these heads are probably more accurately called desiccators than composters (but they do compost as well). When things are working as they should, the end result after five weeks is a material that looks, smells and feels (yes feels) like rich soil.

[Simi 60]

https://youtu.be/l1dnqKGuezo

[SVRocinante]

Originally Posted by CaptTom

...But as one with no experience, it seems to me like you could accomplish the same thing by simply not using the head for #1, and collecting the urine separately...

Thank you CaptTom; interesting idea & certainly a viable option for some. I would definitely consider it if I were a single male. That said, I don't think my wife would like the idea.

While, as you pointed out, the basic principle is the same for these units; separation of urine from solid waste, it's handled by the design of the unit and not by a separate device/process.

Again, appreciate the suggestion!

[SVRocinante]

Originally Posted by Mike OReilly

...I know Air Head recommends the use of poop transfer carriers (coffee filters). Nature’s Head does not, and we don’t use any...

Thank you Mike... I'm really going to dig into the details; hope you don't mind.

OK, so if I'm understanding the process correctly, the idea behind the paper liners is that they act as a barrier between the fecal matter and the hatch leading to the lower holding compartment. Once you "go", you open the hatch with the little lever & bombs away! Spritz the bowl with a bit of water & vinegar solution & Bob's your uncle! Not quite buying it, but heck, I'll take it on faith for now and accept that it works must of the time.

If you're not using anything, then it seems that fecal matter is getting onto the bowl... even if you "go" with the hatch in the open position... no?

It also means that (assuming the bomb bay door is open at all times) when ladies go, a substantial amount of urine is probably going in as well... no?

Again, thank you for the candid answers. This is not a trivial change & I would hate to go through the whole process only to find that it freaks my wife out & I have to revert back to a "standard" head... thus my rather specific questions!

regards,

[Mike OReilly]

Originally Posted by SVRocinante

...Again, thank you for the candid answers. This is not a trivial change & I would hate to go through the whole process only to find that it freaks my wife out & I have to revert back to a "standard" head... thus my rather specific questions!

Definitely not a trivial change, and I certainly don’t mind answering all the questions I can. Hopefully a few other users will notice the thread and chime in as well.

I speak specifically about Nature’s Head b/c I have no user experience with Air Head. Like I say, my understanding is they are virtually identical. But I’ve never used an AH so there may be subtle differences.

With NH, you open the bomb bay doors when needing to take a dump. The whole opens directly to the compost pile. It is large enough, and positioned anatomically correctly, such that almost all the time no fecal matter comes in contact with the bowl. The only time things get messy are when the outflow is explosive.

We do keep a little spray bottle nearby, but it is almost exclusively used to give the urine track a little spritz after use. But it can also be used to clean the bowl in those unusual events. It rarely happens — at least for me.

As far as urine goes, the shape of the basins are designed to separate urine from feces. The catchment basins are all appropriately designed so that things are directed to their respective bins. My wife tells me she does nothing special (and yes, I’ve asked ). She just sits and goes, exactly like a normal toilet.

For us guys, we do have to sit. It’s easy to direct the flow for us, but on some occasions the force of my urine does back flow up over the edge, and into the main main basin. It happens rarely (when I really gotta go, and there’s lots of hydraulic pressure ), but even when it does happen, the amounts are trivial. It doesn’t seem to have any effect on our system.

The urine container is the one that can develop an odour, but only during dumping. When in place all odour is vented to the exterior via the small fan. We spritz the urine track after every use with a few squirts of water. Some people use dilute vinegar or other mixtures. And some people put sugar or vinegar or other things in the pee bottle to keep the odours down. I’ve tried them all and found that simple fresh water does just as good a job, but it’s worth experimenting.

Hope this helps, and is answering your questions. I don’t mind, so keep asking.

[Jim van Cleve]

Originally Posted by SVRocinante

Well, now you've gone and done it!

All this recent talk about composting heads vs flushing heads has got me thinking again; never a good thing.

Here's my situation - we are fulltime cruisers living aboard our Hanse 400e which happens to have a ridiculously small holding tank. If we're extra careful, we (2 adults) can make it last a week... not thrilled with that.

We have no other issues - at this time.
Our head does not smell & I have no trouble doing basic maintenance; I've replaced the joker valve twice & recently replaced the entire pump assembly (Jabsco).

I've looked into expanding the holding tank, but I've not found a viable/cost-effective solution, so I'm exploring the composting head for that sole reason - extended cruising time; theoretically 1 month for a couple.

Which brings us to my questions.

First, in your experience, how accurate is that estimate of 30 days for 2 adults before having to empty?

Secondly, in reading through the marketing material, the Air Head talks about "paper bowl liner for solid deposits" - looks to me like a large coffee filter, but in either case, is this the typical process?

If so, how well does it break up in the solids holding tank?
If not, what is your procedure?

As always, thank you for your time & input!

regards,

You're post begs the question, why is a boat cruising using a holding tank?

[Mike OReilly]

Originally Posted by Jim van Cleve

You're post begs the question, why is a boat cruising using a holding tank?

SVRocinante can speak for him/herself. I think it depends on where, and how you cruise. I want a holding tank so I can visit harbours that may not have sufficient flow, or be sufficiently large, to allow for direct discharge. In addition, there are a number of zero discharge zones where a holding tank is legally required. And in some places, the concentration of boats is such that you just don’t want everyone crapping into the water.

If you’re on passage, or always in anchorages, harbours and marinas with good flow, and are not legally restricted, then a holding tank (or other treatment systems) are not needed. Otherwise, some sort of holding/treating capacity is either needed.

[fxykty]

Originally Posted by Jim van Cleve

You're post begs the question, why is a boat cruising using a holding tank?

Well, if you have a regular wet head, when you’re coastal cruising in places like NZ it’s illegal to dump raw sewage within 500m of any shoreline or marine reserve. And it’s just polite to not pump out in any anchorage anywhere, unless I guess you’re in some cut with a heap of current. And whales - have you seen how much matter there is in one of their dumps!!

This is certainly one of the reasons we’re very interested in switching to composting heads, but for now quite frankly our wet heads are working fine so go way behind all the other things on the get fixed list. Sigh.

[Copacabana]

I think Mike touched on the main points, but I would add a few observations to think about before you make your decision.

With 2 people on board I think 4 weeks is fine for the solids bin. There are a few tricks to get an extra few weeks as well, such as throwing a few handfulls of unmoistened coir to dry it out a bit to buy some more time before dumping.

With respect to how it actually works (urine separation, solids falling into the right hole etc.), it all seems a little suspicious before you use a composting head, but, in practice, it all works out fine. The urine goes to the bottle, the solids fall in the bin. I've had many guests on board and no one has managed to screw up yet. So, I don't think you should worry about that.

But there is the question of what to do with the urine. I think this is one of the drawbacks (or challenges) of a composting head, depending on how you use your boat. People say they go 2 or 3 days without dumping the urine. Maybe it's possible, but in the tropics you drink more and pee more. I dump mine over the side every night before I go to bed. You have to think about what you are going to do with the urine every day or two. If you are anchored out (and the law allows it), it's a simple chore to pull the jug out and dump it over the side. In a marina, I think it wouldn't be appropriate, so you'll find yourself carrying it to the loo to dump it. This may get tiresome ... In a no-discharge zone, I think the urine would be a problem, as you'd have to start storing it until you got to a place to dispose of it on shore. That said, if you can simply dump it over the side (and it's sterile enough, so there is no reason not to), then I think it is a good solution for your needs.

Also, on a larger boat like yours, you could carry a plastic bucket with a lid and dump your solids bin in garbage bag and store it in the bucket, thus buying you another month or so without having to worry about disposing of your waste. Also, if offshore, you can dump the solids overboard (where allowed), just as you would with a holding tank. You also have the option of going into the woods (off the path) and dumping under a tree (what I normally do).

Finally, as Mike mentioned, in normal use, there is no mess after each use. In the rare event that there is some "spray" (sorry to get so graphic!), a piece of tissue paper and a spray of vinegar and water solution takes care of it. You will probably know best if you have a tendency toward this kind of BM. Something to consider if you have sensitive bowels.

And what to do with the toilet paper? If you add it to the composting bin, it fills up faster and becomes harder to crank to mix the contents. I keep a small plastic garbage can in the head, lined with airtight plastic bags (you can buy them in a roll like the kind used in supermarkets for fruit). All paper goes into the garbage can and the lid stays on. There is no smell. Another thing to consider in your decision.

From what I've read from others, I believe the coffee filter is not needed with the Air Head. If in doubt, I'd go with the Nature's Head, which I can say from personal experience works very well and doesn't need the coffee filter. The opening to the solids bin is large enough. No worries.

I would recommend trying to visit a boat with a composting head before making your decision. Get a feel for how it works, the mechanics of it (including removing the urine jug, dumping the solids bin etc.). Also, measure the space in your head on your boat. The Nature's head and Air Head are tall. They all need a flat area to sit on. Most boats have a small raised area where the wet head sits. Will it be difficult to find a flat surface for installing your composter? If installed on the platform (my case), the head is pretty tall.

Otherwise, the installation couldn't be easier. (Ripping out the old system may give you some work though...)

I'm sure others will chime in with more information. If you have a specific question, fire away!

Cheers!

[bletso]

Because of the height, I installed ours fore/aft to have a platform.

[smj]

We have owned all 3, Air Head, Nature’s Head and C-Head. No you don’t need the coffee filter on the AH, just open the trap door and let her rip! The AH and NH need changing about every 4 weeks, the C-Head about every 1 week. The C-Head comes with a setup to continue the composting process and will hold about 4 weeks worth of dumpings. I like the NH over the AH as to me it’s much easier to remove the urine jug, no silly thumbscrews to worry about. I prefer the C-Head over the NH as it’s easier to remove the bucket and dump, and I like the fact that the urine containers are standard 1 gallon milk or water jugs. They start to smell. Throw it away and buy another for less than a buck. My wife prefers the NH. Whichever one chooses they’re all great products.

[Davy J]

First, in your experience, how accurate is that estimate of 30 days for 2 adults before having to empty?

We installed a Nature's Head in December. We then spent twenty six days cruising around the Florida Keys. Never needed to empty the solids container. In fact, I just emptied it yesterday for the first time. As advertised, the solids container smelled like and looked like top soil.

I wouldn't call it my most favorite chore but it wasn't difficult.

During that trip, using the original holding tank, we would have needed a least three pump-outs. It was nice not to have to worry how full the holding tank was. Not to mentioned how much water would have been needed for flushing.

[NRbar]

We have a Natures Head in aft head and electric fresh water toilet with holding tank in forward head. Huge holding tank, maybe 50 gallons. No holding tank smell until full, then when we flush can smell at the vent. No gauge so this tells us to pump out. Never a holding tank aft so waste had to pump to tank forward. PEST.

My wife prefers the NH overall. She puts pee paper in waste basket. I pee in NH and usually poop forward cause my TP consumption has increased dramatically with older age. I am no fan of poop paper in waste basket.

This use has solids going a couple of months before removal. My wife does that into garbage bag. She uses peat moss. We do not use TP or coffee filter before dump. We do open the bay doors first. (This was our only toilet for two years.) No problem with pee in solids that we notice, thank you enlarged prostate for decreasing pee pressure so I don’t have Mike’s problem.

I take care of the liquid every 2 to 3 days. We have two pee buckets so I exchange full for empty and have a couple of days to dispose of liquid. I used to put sugar in pee bucket but forgot a couple of time and never noticed a change in odor so quit that. Sometimes when I dump the pee bucket there is an odor.

No odor from the NH and the toilet does not vent outside cause someone hasn’t got around to putting in the outside vent. Been using it almost 4 years with 1.5 years full time.