Composting toilet: With or without composting medium?

[OliverSnowbird]

I was on the fence between an AirHead and an OGO composting toilet but then came across Separett and Telino.

AirHead and OGO both use a composting medium which has to be stirred after each use.

Separett and Telino simply collect the poo in a bag, without a medium.
They argue that the even with a medium, the time the poo sits in the toilet is too short in order for it to get composted anyway, so why even add a medium, which only takes up space and which needs to be stirred.
I guess this makes sense.

All systems use a continuously running fan, to dry the poo out. None of the toilets (AirHead, OGO, Separett, Telino) seem to have smell issues. All seem to have happy customers.

Does anybody have practical experience with both types (medium / no medium) of toilets?

I like the idea of not having to use a medium but am wondering if I am missing something as the type with a medium is far more common.

Thanks in advance!

Oliver

[rpeter3]

Hi,
Use of a carbon rich cover material is essential for composting toilets. Poo on its own is rich in nitrogen and wont compost.

If you don’t add cover material, you have a bag of poo. It won’t compost and it will smell like a bag of poo- especially on a hot day! Note that the medium needs to be rich in carbon so soil itself won’t work as it wouldn’t burn (no carbon). Sawdust and coco coir are the most common.

The additional carbon rich material also aids in reducing odour by facilitating drying and covering the last deposit. Ideally, use a fine medium that doesn’t allow circulation of air around your poo (sawdust not coarse shavings).

Storing and adding substrate requires space beside your head which is a big benefit of having an agitator. I believe the composting toilets with agitators are Air head, Natures Head, Cuddy, Ogo and C-Head.

Hope that helps!

[Mike OReilly]

I only have direct experience with the former type, in my case a Nature's Head. Composting heads generally do not produce compost at the end of their cycle. They begin the composting process, but true composting takes a lot longer than most users allow. These heads mainly desiccate the feces.

In heads like Nature's, Air or OGO, a mixing medium like peat or coir is used to dissolve and aerated the feces. They rely on air flow, and physical mixing. Used properly, they avoid any unpleasant odours, and can operate for up to a month, or more (depending on the exact head), for full-time two-person crews, before having to be recharged.

The bagger systems also desiccate the feces, but I doubt that action is very efficient. This how hard it is to get air to wet material stuck to a plastic bag. This is why you have to empty these heads much more frequently; days vs weeks.

I bet both would work, but which is the best will depends on how, and where, you plan to use it. If you're never far from a dock, then the bagger systems might be good. But if you plan to be cruising away from garbage facilities for any length of time, I'd go with a more standard composter like Air or OGO.

[thinwater]

Originally Posted by OliverSnowbird

I was on the fence between an AirHead and an OGO composting toilet but then came across Separett and Telino.

AirHead and OGO both use a composting medium which has to be stirred after each use.

Separett and Telino simply collect the poo in a bag, without a medium.
They argue that the even with a medium, the time the poo sits in the toilet is too short in order for it to get composted anyway, so why even add a medium, which only takes up space and which needs to be stirred.
I guess this makes sense.

All systems use a continuously running fan, to dry the poo out. None of the toilets (AirHead, OGO, Separett, Telino) seem to have smell issues. All seem to have happy customers.

Does anybody have practical experience with both types (medium / no medium) of toilets?

I like the idea of not having to use a medium but am wondering if I am missing something as the type with a medium is far more common.

Thanks in advance!

Oliver

You can always bag immediately, between every use. Obviously. Daysailing this can make sense, though you still want absorbent for handling reasons. But if you leave the moldering pile in there without covering with absorbent or sealing the bag ... you will regret that. S__t stinks. They have no magic.



The absorbent, properly selected, helps dry the surface of the poo by wicking moisture away from the surface. Like a dog turd on the lawn or a litter box with good litter, a crust forms and that stops stinking.


--


I tested a bunch of absorbent types, see by side, for an article. With going deep into the details, you need to do something. The people on this thread know.

[Bellinghamster]

A fellow down the dock a way chose a Trelino and said he's happy with it. I'm not sure which model he has, but some of their models are very compact (aimed at camper vans).
Yeah, emptying every 3-5 (assuming 2 "regular" people using it) days isn't really going to compost diddly, so you're pretty much just bagging poo for disposal.

[Sos]

We have a Simploo and don't use a medium but we do put the TP in which helps to dry everything. The fan just drys it out and no smell problems.
The urine smells more so we have fitted a pump to empty the container when appropriate, with a flush of fresh water poured in afterwards.

[OliverSnowbird]

Thank you very much for all your answers.
Your explanations regarding the composting medium certainly make sense.
I also reached out to OGO who said pretty much the same.
This means I'm back at AirHead vs OGO...

Aesthetically, I prefer the OGO. It also seems to be easier to clean, as the upper part does not have to be removed in order to remove the solids container.

I'll be on the boat this weekend and will take measurements but think that space should not be an issue.

Our two old toilets are nasty, one is leaking, the sewage hoses smell and the black water tank has a leaking cap as well as not functioning level senders. The other thing is that our marina stops pump out services 4 to 6 weeks before we take the boat out, what also sucks.

Anyway, a lot of reasons to simplify things.

Since its just my wife and me we'll use one head only for the toilet, the other as a now pretty spacious bathroom without a toilet.

[Mike OReilly]

Look at the holding tank sizes between the Air and OGO. I think (but am not certain) that the Air is larger. Larger bin sizes means longer durations between emptying. This can be both a positive, and a negative, depending on how you intend to use the head.

[OliverSnowbird]

Originally Posted by Mike OReilly

Look at the holding tank sizes between the Air and OGO. I think (but am not certain) that the Air is larger. Larger bin sizes means longer durations between emptying. This can be both a positive, and a negative, depending on how you intend to use the head.

Thank you for the hint, I didn't even think of this.

If seems like the ORO has a slightly larger liquid tank of 2.4 gallons vs. 2.0 gallons.
The AirHead however has a larger solids bin of 5 gallons vs. OGO's 3.4 gallons.

Oliver

[MikeHoncho]

I've had my OGO for two seasons now and continued to have moisture issues. The dryer you can get everything the better. I had condensation build up on the inner walls of the toilet. I built a fan case and placed it inline in the vent line venting outside. I will see how this goes.

[OliverSnowbird]

Originally Posted by MikeHoncho

I've had my OGO for two seasons now and continued to have moisture issues. [...]

I saw your post just now, after I ordered the OGO over the weekend. I hope I will not have the same issues.

I am however wondering how condensation can form since the fan should create a constant airflow and since the inside and outside temperature of the toilet should be about the same.

[dlj]

Originally Posted by MikeHoncho

I've had my OGO for two seasons now and continued to have moisture issues. The dryer you can get everything the better. I had condensation build up on the inner walls of the toilet. I built a fan case and placed it inline in the vent line venting outside. I will see how this goes.

I've been running my OGO for a couple years now and have not had this problem. I'm not sure what may be different from our two applications.

I'm very happy with these (I have two of them).

dj

[Mike OReilly]

Originally Posted by OliverSnowbird

I saw your post just now, after I ordered the OGO over the weekend. I hope I will not have the same issues.

I am however wondering how condensation can form since the fan should create a constant airflow and since the inside and outside temperature of the toilet should be about the same.

I've not used an OGO, but as you point out, a properly operating composter shouldn't have excess moisture in the main bin. The moisture is managed by the fan, and also by the bedding material.

Getting and maintaining the right balance in the bin is the main skill required to operate these heads properly. Since moisture in the bin will depend on what gets deposited, and since everyone is different in their outflows, it might take some time to get it all perfectly Goldilox balanced: not too wet but not too dry; something 'just right.'

I've learned to read (and feel) this via the manual churner on my Nature's Head. The OGO uses an electric churner, so I'm not sure what the signs will be, but I'm sure it's just as easy.

[dlj]

Originally Posted by OliverSnowbird

Does anybody have practical experience with both types (medium / no medium) of toilets?

While I have no experience with no medium toilets, it occurred to me that the experience I do have with medium containing toilets may shed some light. As to how well they work, no idea. But, I will say emptying is not always perfect. I would hesitate getting a no medium option as during transport from head to disposal isn't always the perfect trip. Walking down the dock, nicked the bag on something sharp I hadn't seen and a spill occurs. Get another bag to wrap, and clean up whatever spilled. Now with medium in the mix, that is like cleaning up dirt. No medium in the mix? I'm not so sure that would be as benign....

dj

[dlj]

Originally Posted by Mike OReilly

I've learned to read (and feel) this via the manual churner on my Nature's Head. The OGO uses an electric churner, so I'm not sure what the signs will be, but I'm sure it's just as easy.

I just open the top and look in. The motor sound is indicative of how things are going. I'll always open and look when the motor sound changes. Sometimes I look just to be sure things are looking balanced... I run the motor between usages. Typically once or twice a day even if I haven't used the solids bin. Seems to keep things running better.

dj