ELI5: How do compost toilets work

[vjm]

Many people don't separate the toilet paper. It just breaks down slower than fecal material and your container will fill up more quickly.

[Minggat]

I recommend that you abandon the "breakdown" concept just to help you sort out what you're really dealing with. Think dehydrator rather than composter.
There is no negative impact of the TP on the dehydration process. I would have to say that it even aids the process. But you will no longer have a product that you can pass off as compost. Basically you're going to have trash in the batch. It won't be wet, so it won't be "breaking down"

[Cthoops]

Originally Posted by tankersteve

I'm convinced and actuallly have a cardboard mockup of the C-Head in my boat. Once my critical work is done, it is high on my list of upgrades.

However, I have to admit, I was not tracking the need to separate the TP. Does anyone not do this? I understand TP would inhibit just putting the dessicated waste in a flower bed, but if disposed of in other ways, is there any impact in TP going in with the solids? Possibly using camper/RV TP to aid in breakdown? Or is this just something I'll have to adapt to?

Thanks.

Tankersteve

I separate my TP for urine (but I'm a chick), but we put the TP for solids in the bin. It may fill up a bit more quickly, but it's better than the alternative IMO. We use our regular home TP, but we separate the squares so it doesn't get wrapped around the agitator.

[daletournier]

Hi, is there any smell that comes from the venting fan? I'm assuming fan needs to be somewhere that seawater or rain can't flood in?
Cheers Dale.

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[tankersteve]

Thanks so much to the responses about TP. This just confirmed that a composting - dehydrating - toilet is the future for us on our boat.

Many years ago, while in Iraq, I lived in some Iraqi buildings with toilets that required you to separate the TP. I was not a fan of this and really didn't want to resort to having to do this in my 'home'.

Tankersteve

[Minggat]

Originally Posted by daletournier

Hi, is there any smell that comes from the venting fan? ....

Vent fan is to aid in removing humidity/ moisture as solids dehydrate. Not for odors. There are no odors once you crank the handle and the solids are covered by the drying media.

Again, the vent and any fan are NOT required in most cases, depending on which unit you choose or how you choose to operate it. Even when I used to deploy the lid to the solids bin, there was no smell. Just a less dry batch.

Believe me folks, the questions that have come up here are results of the same worry and overthinking that I went through. The worst thing that has happened was when a clueless crew emptied the urine in the solids bin. The resulting ammonia smell was taken care of by dumping that batch and starting a new one. The "earthy" smell that some report is very very faint, and hardly offensive. Any issues that you might have will be operator errors of the non-life threatening variety.

[captlloyd]

Originally Posted by Minggat

I recommend that you abandon the "breakdown" concept just to help you sort out what you're really dealing with. Think dehydrator rather than composter.
There is no negative impact of the TP on the dehydration process. I would have to say that it even aids the process. But you will no longer have a product that you can pass off as compost. Basically you're going to have trash in the batch. It won't be wet, so it won't be "breaking down"

While the rate of decomposition may not be the same, toilet paper is indeed a compostable material. People use newspaper in their gardens all the time for mulch which degrades into compost eventually. Any organic matter can be turned into compost. However some types of fecal matter is not considered a good idea for vegetable gardens, including human . Human waste compost is OK for flower gardens.

[Minggat]

Originally Posted by captlloyd

While the rate of decomposition may not be the same, toilet paper is indeed a compostable material.

Of course true. That rate of decomposition is the point I was addressing.
Again, TP will not be a negative to the process.

[Nicholson58]

I am sure I have posted these before. Our installation of Air Head. Our boat has 3 heads. Two are Vacuflush. One of those is direct out only and the other has an optional holding tank. The forward head had been removed by the PO for a shower & rinse for SCUBA or fishing tackle. We added the Air Head to comply with Great Lakes ZDZ. The original head was on a rise defined by the hull shape. We added a 3/4 inch thick Lexan floor so the throne is a step up. The electric fan vent furnished was not installed. We ran the exhaust to a NICRO vent with solar charger. These have not been reliable for many due to crappy NiCad batteries. The NICROs typically reside on a shelf long enough for the battery to become junk. Replace it with new or Li. A simple plastic plate will make an adapter. The little one-step child's seat/stool is a big help and is useful other places on the boat.

We do not have stinkintheboat. The only problems with operation is when we have had to use dry leaves as compost. These themselves compost rapidly turning the pot into goo. We now buy Coir on line in 40-brick/50 # batches. Should last a while.

[Schooner Chandlery]

Originally Posted by jcdexter

We've been using an Airhead on Tribute for 6 years. We have the fan and have zero odor. Ours is a two head boat. I've had to rebuild the Raritan which is also 6 years old twice and replace the hoses once because they became completely clogged with salt. The Airhead has required zero maintenence. I wish both my toilets were Airheads. Two Airheads would allow two people to go 60 days without emptying. With the help of Geoff at Airhead, I plumbed the urine container into my holding tank with a simple foot pump. Works great!

We're used our airhead 5 yrs just emptying two urine tanks as needed. We recently installed a whale tiptoe foot pump and plumbed to a holding tank as we're in a marina this year but the pump only worked about week. I've yet to take it apart to figure the problem out. What kind/brand of pump did you use?


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[jcdexter]

We use a Whale Gusher pump. It's only been in a few months but so far so good.

[Ribbit]

Originally Posted by captlloyd

However some types of fecal matter is not considered a good idea for vegetable gardens, including human . Human waste compost is OK for flower gardens.

Not true. The contents of Earth Closets always went onto the compost heap, and then onto the vegetable garden (back then most gardening did not involve flowers). It was perfectly safe.

Most fertiliser used in Eastern Europe even today, is human waste, and they have very good crops.

I have traveled widely around there on my motorbike, and the smell is distinctive.

Heck it is even good fertiliser to pump into the Oceans. That may not be a popular thing to say to the misguided, but it is the truth. Life feeds on it voraciously.

Even where I live, farmers use their slurry tankers to empty septic tanks when needed, and then spray the contents on the fields. Sunlight and aerobic bacteria make short work of it, as they do in the sea (if the fish don't get to it first).