System sizing for l...
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System sizing for low volume applications  


New Member
Joined: 1 month ago
Posts: 1
26/04/2020 7:44 pm  

Hello Wendy,

Thank you for all the very helpful information, and I hope this line of questioning isn't too redundant.

I'm thinking of building a vermicomposting toilet system in Hawaii that will serve a very small house. In general it will be just me, although I'll have occasional visitors. My basic question is this: is there a downside to having a larger system, such as those based on the IBC tote, when usage will be low relative to its capacity? Would the worm ecosystem adjust and thrive to the low throughput? As an alternative to an IBC tote, would I be better off with a smaller volume bin, perhaps something like a 100-150 gallon stock tank ( , or fitted with a lid?

Both of the example stock tanks are lower height (20-24") than an IBC tote. I'm guessing the height of the biomass column column is important in terms of providing adequate retention time and distance for the liquids passing through to receive adequate biological activity prior to moving on to the greenfilter bed? If so, for a small volume system would I be better off going with a taller, narrower worm bin, perhaps a 55 gallon drum?

I would appreciate any insights. Thanks.


Eminent Member Admin
Joined: 4 years ago
Posts: 40
06/05/2020 4:06 pm  

Hi Cedric

An IBC tote will be just fine for one person. Mine is a similar situation, attached to a tiny house. Through the summer there can be anything up to 10 people using it but in winter it goes down to just me. It adjusts. If there's less food to go around, worm numbers decrease accordingly. Personally I would sooner have capacity to spare than downsize. You can always top up with kitchen scraps or some animal manures if your worms' bellies are bothering them 🙂

Hope that helps.