Composting toilets, do they actually work?

[Kettlewell]

Comparing old, poorly maintained heads to new composting systems is also invalid. Visit a boat with a good holding tank system and its existence will be without evidence.

That may be so, but those boats are few and far between. I have noticed the distinctive head and holding tank smell onboard new boats at the boat show.

[skipmac]

Originally Posted by nautical62

I installed one on my Hunter, by placing a tank just above water line under the vanity counter. I placed the out take on the bottom with the inspecting port directly above, so it could easily be snaked if ever needed (which it didn't). I like the bottom of the holding tank just above waterline so when sailing water will be forced up in and drain out, offering some cleaning action.

Have not installed it yet but this is pretty close to what I have designed for my boat. Main difference is the holding tank will be behind and above the vanity but drain out the bottom, waste in on the top.

So how was the pump out rigged? I'm planning to put a Y-valve on the single bottom drain line which will switch between the thru-hull and the deck pump out and trying to think if there is any reason why not to do it this way, other than problems with the valve (but I'm using the Peg Hall recommended, never fail valve).

[Mike OReilly]

Originally Posted by Orrjames

I want to redo our head system and if a composting toilet is actually worth a crap I might try it. Get rid of the smelly holding tank and all of it's parts. Whats' the buzz about them?

Like with many things in cruising, there is rarely one best answer for everyone (despite what you often here on CF ). In the case of heads, each approach has its advantages and disadvantages. Clearly it is perfectly possible to have a well functioning standard marine head. The same is true of a composting head. Poor operation and maintenance of either system will result in a crappy situation .

I have chosen the composter option for a number of reasons, the main ones being:

• greater autonomy (not chasing the next pump out station),
• recovery of storage space,
• operating simplicity,
• operating cost,
• and perhaps greater safety (fewer thru-hulls).

The downsides are going to be:

• upfront cost (for NH and AH, but not C-head)
• an increased in the effort of basic operations (dumping & churning),
• constant dumping of urine bottles,
• the added difficulty of emptying a full head,
• added challenge of managing guests.

For me and my spouse the balance easily tips to the composting head, but others will have different needs and priorities. Both systems can work well if done right and applied appropriately. It comes down to understanding your own needs and limitations.

[Kettlewell]

By the way, twice in the middle of the night I awoke to the sounds of gurgling water and someone had left the head intake open and for one reason or another water was siphoning into the boat at a rapid rate. One time, on another person's boat, I lept out of the berth into water over the floorboards. Hence, on my boats with standard flush heads part of the routine is to always close the water intake after each use, no matter what, but even then sometimes people forget. That's a nice advantage of a composter. On some boats, particularly multis, you can position the top of the bowl above sea level, which would reduce this threat.

[model 10]

Kettlewell; All of those problems were because something was screwed up in the system. If I had to shut the seacock everytime we used the toilet, I would get a compost set-up too. Thankfully our system does not sink the boat and I don't believe it will either.

[ShaktisBoy]

My wife and I just installed our second Airhead composting toilet in our new catamaran owners head. Next month we plan on adding a second Airhead to the guest side. We feel a composter is the only way to go after having had both systems on two boats now. One caveat tho is spend some time planing where you are going to vent to. On the mono we ran the vent line all the way aft on the port side and pretty far above the water line. This has worked well with zero problems for several years. On our new cat the venting options were not as obvious and we had to place the through hull vent in the tunnel between the hulls, about half way aft and this caused a problem with large following seas actually making it into the vent line and shorting out the fan upstream in that line. The fix is simple enough but wasnt planed for in the origional setup. Now the vent line comes in then makes a 90 degree verticle turn before continuing forward to the new fan installed midway to the toilet. I also incorperated a low spot drain in the vent line just in case water somehow makes it past the verticle turn. In the near future I plan on fabricating a simple door on the outer scupper shield to automatically close if a wave hits it from behind. Now on to a mod we made to our new head that some might find real usefull. After years of disconecting the urine jug every other day to take topside to dump, I decided to make my life easier and installed a drain in the bottom of the urine jug and connected a 12 volt liquid pump like this 12v Marine Utility Water Pump mounted behind the head and ran a connection to a TEE at the top of our existing holding tank. Now instead of disconecting the jug we simply flip a switch and 5 seconds later the urine is empty. The advantage now is only urine goes in the ships main holding tank and we can go for more than a month before having to pump out or go offshore to dump. There is now only 1 hose to the drain through hull and one to the top of the tank. No more smelly vent loops. No joker valve, no return line just 1 lever to empty the holding tank every month or two. By the way we are full time live aboards and there is no longer any head odor in our boat. There is a mental and physical learning curve with these as well. The physical takes practice ie do # 1 and # 2 seperatly. Do not let #1 mix in #2s tank or else"! The mental is simply learning how to prepare the initial compost. If you do it right you will be pleased with the results.

Pictures of our install are available if anyone is interested

[valhalla360]

We went natures head a few years back:
- Urine tank lasts us 3-4 days (not daily as someone suggested).
- Soids lasts 3-5weeks depending on use. Easy to dump overboard if offshore or cover with heavy trash bag and flip if inshore. No need to search for pumpouts that are always broken.
- You can get away with a few days once it's "full". With a holding tank, full is...well, full, you are done using it.
- Far less to break or go wrong.
- Guest instructions: #1 - just go, #2 - open the trap door first (worst case they leave the trap door open and don't churn). Hardly the rocket science of open a valve, pump 3 times, do your buisness, close valve, pump until empty, open valve...wait where's the valve?...Oh %@#, it's not going down can you come help. I think I broke the thing...and so on.
- No odors. Apparently some people have the magical ability to eliminate odor with a holding tank set up but I've yet to meet one.

No question, we far prefer the composter.

[Kettlewell]

I had the same problem of a ruined composter vent fan when we took green water over the decks offshore, so I now run the vent hose to a Nicro water trap ventilator up on deck. The fan is just a little computer fan, and I replaced mine with one from Radio Shack that was the right size.

As several have mentioned, it is really ideal for most guests for two reasons: it is super simple to use, and there is no way they can goof up that will either endanger the boat or not work properly.

[boatsail]

Some say their holding tank does not smell like one. Some say their engine compartment does not smell like mine... My wife has not found either of those statements to be true. That being said, she has no complaints about the composter

[lorenzo b]

Do they work? Yes. Sewage treatment plants also work, but do you want one on your boat? It's a lot easier to use a large holding tank and pump out in deep water or a pump out facility.

[xeon_tsd]

I would go read "Breaking Seas". The author self published via Amazon. Great read, and his experience with composter heads was at a minimum entertaining. Reading what NOT to do can sometimes be more valuable than reading what TO do.

[finleyg]

On our recent nightmare voyage (detailed elsewhere..) where nearly everything went south, despite serious preventive work, our C-Head worked like a champ. 4 people on board, several days, no smell other than at the moment of production of "product." I then dumped the blended product in our household trash when we returned, it was not even identifiable as fecal matter, and smelled like potting soil... Probably less environmental impact than a diaper or two. Nobody had probs using and it was the only thing that went "smoothly." Heh.

[Kettlewell]

Kettlewell; All of those problems were because something was screwed up in the system.

^^Yep^^ I like systems that don't potentially sink the boat when things get screwed up--it is just a matter of when, not if.

[s/v 'Faith']

Originally Posted by lorenzo b

Do they work? Yes. Sewage treatment plants also work, but do you want one on your boat? It's a lot easier to use a large holding tank and pump out in deep water or a pump out facility.

Spoken like someone who has no idea what they are talking about.

What brands of com posters have you used? Aboard what boats?

[s/v 'Faith']

Fwiw,

I have just cruised 6 months aboard a boat with an airhead, and I have owned and installed Natures Heads aboard my boat and a friends boat. They work very very well, and are much less muss fuss and odor then holding tank equipped boats.

The quality edge goes to the Natures Head, much better fasteners and construction. No experience with the c-head, but many say it works quite well.

Proper compost medium is necessary, I find coco-Tek to be vastly superior.. Do a search on compost medium for more...