That is my understanding. However I have had a few for a while now and between particle size, bar size, moisture, and material flow down or not flow down, I think I am missing something. That is what we are doing here. Trying to find the perfect system.

There's also a cloth flow through system called the Worm Inn. Same basic principle though.

I have also seen a Worm Swag from Australia, and someone that turned an old pair of jeans into a hanging flow-thru system.

Marcus, you're right. That's basically all it is. The main advantages of the system are:

1. Hot air rises, so air is pulled in to the middle of the system from the bottom. (Oxygen is the rate limiting factor in vermicomposting.) This seems to be one of the best ways to get oxygen in throughout your bin (rather than just the top 6 inches or so.)

2. Harvesting is easier than with most systems. Worms go where the food is, so if your column of food is high enough, when you harvest the bottom, there are VERY few worms there to be removed from the compost.

Thanks for the confirmation, now I will recycle two bottomless garbage cans into flow through systems.
Dan

FYI, it doesn't have to be cylindrical. It does need to be tall (minimum 20" if possible). Some folks have used smaller containers with less depth, but the VC harvested must almost always be screened to remove worms and cocoons.

Andrew

Lots of examples of flow thru bins at the link below

Here is a link that might be useful: Collection of DIY Flow Thru Bins