I was thinking for my second bin to go up from 1/2" to 5/8" and really sand both sides down, so flow-thru would be a lot easier, at least on the bottom. I like having 3/8" holes on the sides (three rows spaced about 2" apart and in an uneven pattern for air, near the top, in order to prevent flies etc from getting in easily, on both sides and ends.)

My first bin ~ which is still my only one, has holes 1/2" in the bottom and I haven't really lost any worms thru them yet, wondering if perhaps my fat worms are too fat to make it thru? I guess I will have to enlarge them up to 5/8" too, once I get a chance to clear out the bin.
(EF's here)
Gina

can I make any sized holes and line the bottom with window screen to prevent worms from escaping that way?

Organic.. This method used a couple tubs for harvesting. One had holes in it the other did not. Look up his post and you will understand.

I tried the method yesterday using a couple small tubs from the hospital we get sterile supplies in. I did not do too well but I think I was just impatient. I had to get to the hospital and maybe put too much vermicompost into the top tub. Some of my worms just laid there while the others went down into the fresh bedding on their own like hey were supposed to. I started chasing them by pulling compost off the top to sift but that defeats the original purpose-letting the worms do the work.

I did a halfbaked job so will go back when I get the time.

As for your question, The last bin I set up has no holes in the bottom at all. I used a 5/32" bit to drill a grid of holes around the sides at the top. I am using kitty litter buckets so they are only about a foot high. The bin I was trying to harvest had holes in the bottom. When I set up the bin I had folded cardboard and put some on edge thinking that it would allow air to flow. When I dug down to that level there was a packed mass of vermicompost and some of the cardboard with a ton of worms. The holes were obviously plugged. I do not think ventilation was a concern in this case.

I thought the problem was the worms were heading down into the catch basin via the drain holes. I understand the harvest deal with the fresh stuff in the bin on top as the worms supposidly hang out in the top layer of stuff anyways. Does the top bin actually touch the compost of the lower bin or is there a bit of a gap?

Organicislandfarmer & gmw1:
Your questions concern raising worms and should be posted elsewhere. This thread is only about my idea for separating the worms from the castings and those are the only questions I'm going to address. That said;
Hi pjames: My worms are all EF's. I space the holes quite close together, like maybe 1/8" apart. The idea was that wherever the worms were, there would be a hole right there to move down through. The bowl I used (with the holes) is about 3" high & I filled it to 2". That's too much.
You know, the system where you dump it all on a plastic sheet on the floor, and then scrape away an inch and the worms move down away from the light; and then scrape away another inch, and so on... well this is the same idea, except that you can process more, faster. The next time around, I'm thinking something shorter (for the strainer), like a pie plate but with straight sides. A worm will hide under anything that provides protection from the light, even a tea bag, so the less it has to hide under, the better. Lately I've been cruising the plastics and kitchenware stores, looking for a container (like a pie plate but with straight sides & 1" high). I found a base for a flower pot (you know, the plastic pan that sits under a flower pot and catches the water runoff), that's exactly what I'm looking for. Now to visit a nursery and look for more of the same. To sum it up: The shorter the sieve container, the less place there will be for the worms to hide under and the more reason for them to quickly move down into the wet shredded cardboard. Also, the more containers you have to work with, the more castings you can process at one time.

Shaul

I bought a plastic garden sieve from the local hardware store. It's probably about 18" diameter with 1/4 inch holes and the bottom sits about 1/4 inch up from what its sitting on. I lay out a piece of damp weed cloth on the table, sit the sieve on it and add about an inch of castings. The worms go down onto the weed cloth where I can easily pick them up after. I stir the castings occasionally with a spatula in case any worms are feeling too comfortable in the castings.

It works well, but still time consuming.

The sieve was only a few dollars, and sounds like what you are trying to make.

Yep, it's the same idea. But instead of weed cloth and having to pick them out one-by-one, my sieve sits on top of another (larger) container that's filled with wet, shredded cardboard. The worms go down into it and then at the end - I just dump the whole thing (worms, cardboard & all) into the new bin. The more sieve-containers you have, the more castings you can process at one time.

Shaul

I used a modified version. My holes may be a little far apart and too few (1 inch or so). I sat ont he patio and watched the worms then agitated them skimming off the top portions. Some of the worms dove down to the catch tray, others laid there. Part of my problem was I was impatient letting the worms do the work.

I did find that my top pan also works good as a sifter. I got some excellent castings from my harvest this week. Castings and coccoons with only a few tiny scraps of bedding.

Is anyone here using the Worm Wigwam? I'm thinking of buying one but it would be nice to have some input from current users. It costs $560.00 plus shipping which I would not mind if it is really a good system. I currently have 3 COW tiers of 3 bins each, all in service.

$560 PLUS? Dave,I would have a very hard time justifying that type expense for ANY system. Especially when one could manufacture a home unit that would probably work as well but not be as pretty.

Thanks Shaul

That's good advice and I will certainly give it a lot of thought before I make a decision.

Dave