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Hi, as a newby to boating, I know of pumpout and cassette toilets, but composting? I have found out that the waste is heat dried and shaken into a powder and you have to empty the tray 3-4 times a year. Downside is cost, £2000-£3000, upside is savings on pumpouts and emptying of cassettes and as an exteral flue is included, little or no smell, so why is this not the toilet of choice? Or am I missing something? Your comments would be welcome. Many thanks, Tony.

Asked by: Anthony Burnell  | 10.14am, Wednesday 9 June

WW says:

Composting toilets tend to be an aquired taste! They generally need to be in constant use- if they are unused for periods of time (say, more than one week) then they can have problems.
They are well-suited to residential craft, but they do need "tending"- and, despite all the best efforts, every one that I have come across in boats has a certain odour, that might be best described as "woodland earth" which permeates the bathroom at least. Extremes of temperature can also affect both the rate of decomposition and potential malodours.
Also, some of the units require a 230V supply, while other are either 12V or natural fan assisted. They also tend to be quite bulky in size. There is a potential issue if there is a sudden influx of use (say, extra guests onboard) with some models of loo, on a boat. The microbial colonies take time to establish, and they are not quick to change in number when additional load is applied.
It must be said that the second-hand market doesn't view composting toilets as an asset to the boats value. Several owners who have fitted them have removed them after a few years, as they had issues with maintaining them. In an enclosed system, there is also the issue of non-normal faecal waste- such as if someone has a gasterenterinal infection- the waste might not break down in time to prevent serious cross-contamination, as the waste unit is not sealed.
If you can cope with them, they are quite good, but might make selling the boat not as easy. Most boaters appear to like toilets they can clean easily and, if not residential, can be left quite easily for weeks (or longer) between visits to the boat, and so go for portable/cassette or pump-out toilets, with a suitable treatment fluid in the tank.
It comes down to personal choice- but for the majority of boaters, they are rejected on the basis of cost, ease of use and tolerance of the crew!

Mark Langley  | 10.31AM, Wednesday 9 June

The Whilton canal Shop has one that seperates solid and liquid waste, the pee going into a seperate container or tank. this might work better since the major problem with composting toilets is getting rid of all the water. Some have heaters to evaporate the moisture, but these are too power hungry to be practicable on a boat.
I also spoke to some live aboard owners with a composting toilet who said it produced some lovely compost when they were away for a couple of months!

Rupert Smedley  | 9.25AM, Thursday 10 June

Readers say:

Mark. Thanks for that, cassette toilet it is then for me, and pub loos for my guests,(joking). Tony.

Anthony Burnell  | 10.55AM, Wednesday 9 June

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