I think i would prefer many smaller bin since it should be easier to use in general (feeding, moving, harvesting, cleaning, etc). Temperature should not really be less stable in smaller bin. If i had to do it, to optimize the space, i would probably use stacked rectangular bins, a little bit as the COW works, but larger rectangular bin (maybe around 3 feet square), and i would feed all the bin in parallel, not only the top bin.

I use the stackable Rubbermaid bins. However, instead of dropping one bin into another, I also use the lids.
The lid was drilled at the same time I drilled the bottom of the bin so the holes(1/2-5/8" dia.) allign to make easy migration.
This means instead of using lid of bin A on top, it is used to cover the bin below it, where the holes line up.
At the moment I have a stack of 4 bins, 2 finishing and 2 started about 3 weeeks ago.

Since the worms don't always just travel UP as we hope they would, I positioned a new bin between the 2 finishing ones and another new bin on top.

I also use an additional bin to catch any leachete, with holes drilled on the sides. Worms will migrate down into that bin when the system produce leachete so add a handfull of shredded paper/cardboard to soak it up and to allow the worms to survive.

To support the weight of all these bins (they get VERY heavy) I put 3 (upside down) empty cans along the centre of the leachete bin. Making sure they are the right height, of course, or stack 2 cans to make up for 1 of the right height.

I can add more bins on top but I think a stack of 5 is the max. Then I will start another stack. I find this is the easiest system for me to be able to move them in/out depending on the season. And it provides multiple surface of worm habitat than just the sq.ft. it occupies.

Hope this helps. Sorry it's a long post.

Otis

Thanks for your comments. One of the things I don't like about the COW is the difficulty getting the trays apart when full. The stacking Rubbermaid tub designs seem like they would be even worse in this department, but Otis' solution could solve this.

If I were going for bigger stacking system, I can envision exactly the kind of heavy duty stacking tray I'd like. If you can picture in your head the trays you see bread delivered in to grocery stores except with the side solid instead of with holes, that's what I'd like. I even found a company that sells this item I have in my head in all different sizes. (I was thinking 24" x 18" x 10" deep.)Unfortunately the minimum order is 100. :-/

I've also looked at stacking recycling bins, like the one Rubbermaid makes, which is basically one of their tubs with a taller lid. It would be easy to check on each level and the lids would keep the light out. They are pricey, though, and you'd still need to make a drip tray. See link below.

Does anyone prefer the larger bins? My Mom knows a lady that has a small business farming fishing worms that uses one large bin but I haven't had a chance to go over and talk to her. She's 88, so moving and maintaining stacking bins might be too much for her.

I wish I'd been "getting rid" of my worm castings by throwing them in my garden for the last few decades! You should see the veggies she grows.

Here is a link that might be useful: Rubbermaid 14g recycle bin

If I were in your situation, I would go with a flow through system. There are not many good small-scale flow through systems. The Worm Inn would be a good option. The Worm Wigwam is probably larger than you need, and is very pricey. Or you could try to cobble one together yourself.

alabamanicole:
That recycle bin does look pricy.
I just checked my blue RM bins and I calculated that they are about 14 gal. too. I bought them on sale last year for about $5 CAD (so cheaper for you guys south of the border) and I bought 6. The big investment was the purchase of the worms.

The trays you have in mind sound really good; saves you the trouble of drilling.
As catch tray you can always find something. The worm tray doesn't really have to fit snuggly (?) onto that. You could "engineer" something, line that with plastic, and put bricks or upside down empty cans (my favourite, lol) for the worm tray to sit on.
Those Rubbermaid shoe/boot trays came to mind.

About the min. order, you might be able to find fellow farmers of same mind.
If you were close by for me to drive to and depending on the price, I would have easily taken 30 off you.
Just curious, how much do they ask for them?

Otis

sbryce - Would I want to do a flow-through system indoors? I envision all kinds of mess with one of these systems, although conceptually having the compost magically drop out of the bottom and avoid sifting sounds very attractive.

Otis,
I did not send in a price inquiry. I can't find the other company I looked at, but this appears to be the same actual item:
http://www.flexconbins.com/subcategory.php?categoryid=143

The 24"x15"x9.5" sounds like a good size, but it's $21.71 for orders under 100, and it says it can be stacked to 150 pounds, which doesn't sound like it's really that sturdy.

This one is $14.72 for 22x17x8", with quantity discounts starting at 8 units. 50 pounds per container and the bottom container can support 250 pounds. This sounds more feasible in terms of sturdiness:
http://www.usplastic.com/catalog/item.aspx?itemid=22991&catid=537

There are other companies selling what appears to be the same or similar products for the same price ranges, so I won't bore you with the links.

A single large stock tank from the local farm supply or Rubbermaid Roughneck tubs are looking better all the time. :) The 10-14g versions run about $10 each here but you can often find them on sale in the $6-7 range. I tried to find the stackable capacity or sidewall strength of the tubs, but to no avail. I know when filled with water they can significantly distort but can usually take the abuse if you don't try to move them, and that's a lot of weight. You can't do that with the Sterlite versions and other brand names.

I suddenly have the urge to bribe the guy that fills up the drink & snack machines at work to "lose" a few of his tubs...

My flow-through has not been going long enough to do my first harvest, so I don't know just how messy they are. The one I built has no bottom, and it sits in a shallow Rubbermaid tub. I am expecting the Rubbermaid tub to catch any mess.

I have just finished harvesting a stacking system made from Rubbermaid tubs, and I can tell you that it is a messy deal, though not nearly as messy as the dump and sort method would be. Even after 3 months, not all of the worms migrated up, so I still had to screen out the remaining worms. This was done over several days, as the vermicompost was too wet to put through a screen without giving it a few days to dry out.

alabamanicole: thanks for the info. They're too pricey for me; too bad.

sbryce: when my RM was done and I was tired of picking the worms by hand from the tub whenever I was "checking", I buried wormfood in a plastic netting and got most of them. Mind you they haven't been fed for quite some time.

sbryce, I have a new flow through. It also is small, 8 gallons. I bet it is similar yet different than yours. Reading about yours, now I have another design I want to try. No bottom sounds like a good way to go. I went that way too. The air flow should be great and no more digging into bins unless for fun.

In general comments, In a bin, I think it is easier to convince 95% of the worms to travel down than it is to convince 70% of the worms to travel up. And in much less time. If only because the top is easier to dry out and the bottom is the last to conserve moisture. Maybe the worm trays should be fed in the bottom tray not the top. But then moving all those trays each time would be not fun. Thus the interest in flow through for those who have enjoyed harvesting (and bothering the worms) but are not sure why we doing it this way.

In a flow through the food and the moisture concentrate on top and the bottom is the dryest. At least that is what I have read the theory is.

alabamanicole, I agree bread trays do look ideal. To test your theory, real bread trays, holes in the sides and all can be used. Put cardboard along the edges, save BIG BUCKS $$$. Worm castings "is heavy". If no bread trays land at your feet you may already have milk crates that can be cardboard lined. The worms will stay inside where it is moist. I have always wanted to try this experiment. And eyed the bread trays. Another tray to try would be easy to get now, the trays 6 packs of pansies or vegetables come in. If the weave is too big use two different styles together for together each layer.

I'm still working on the "compost magically drop" part but fully expect to get there.

No bottom was mostly because of the way I built my bin. I didn't start with a barrel of any sort. I made a rectangular column out of old corrugated plastic campaign signs. Then I found out that they are made of polyethylene, which can't be glued! I kinda-sorta stuck then together with silicone caulk. The idea was to save money by not having to buy a barrel, but that was offset by having to buy several tubes of caulk. I also wanted a rectangular bin, rather than a round one.

So far, so good. We'll see what happens when it comes time to harvest.

For a grate I used 1/2 inch PVC pipe. It is arranged in a PVC frame, which the campaign sign column is screwed on to.

The surface is 19 x 21 1/2, with a depth of 22 1/2 inches. The size was determined by the size of the Rubbermaid bin I am using for the bottom. The top edge is framed with 1 x 2 wood to keep it from bulging and hold the campaign signs together at the top.

A "rectangular column" sort of speaks to my post on kitchen tube compost. Column idea being the same in both. Not spending money does seem to be central to the idea of recycling. Spending money where one seems to need to does include caulk to facilitate experiments. Polyethylene, I'm thinking duct tape. Did the worms crawl into the "corrigation"? Because that would be sort of gross because I do not know how to get them out of there. The plastic could be loosly stuck together to allow lots of air. I am most curious to know, "Is the open bottom sitting on the bottom of a bin?" Thus when you raise the plastic sign to harvest the vermicompost good things will happen?

sbyrce: "My flow-through has not been going long enough to do my first harvest, so I don't know just how messy they are. "

Hmmm. I thought flow-through systems were more or less continuous harvest? Sounds like I need to do some more research on this design.

Otis - I agree, too pricey for me, too; they don't make sense for a home system unless they'd last significantly longer than a Rubbermaid tub system. Of course, cost of material versus buying worm castings would have a positive ROI, but I'd rather get my worm castings for nearly free.

equinoxequinox - My worms love to eat cardboard and would no doubt dangle out the sides of a bread tray and end up on the floor for the cat to play with. I hate finding them crispy. But if bread trays did land in my lap, I would probably find a thin plastic material to line them with.

I am intrigued with the idea of moving the worms *down* instead of up. Hypothetically, if you could figure out a way they could move downward but not back up, or at least significantly discourage it, then you could let the top tray dry, take it off and run it through a shaker to grab any cocoons and have finished castings.

My first thought is back to the stacking bins with lids, like the ones they sell for home recycling, which would permit feeding of the lower levels. There would probably be an air gap that would discourage upward travel, but I'm not sure that a barometric pressure change that sent the worms deep wouldn't mean you ended up with unfinished compost.

I am getting a lot of good ideas here. What I really need is a design that uses empty kitty litter buckets. :)

For those looking for barrels, if you have a local soda bottler they sometimes get rid of (or have vanish) 55g drums. I got some off FreeCycle once that I wanted to use for rainwater collection, but they turned out to have had some automotive chemical in them instead.

Flow-throughs are continual harvest AFTER they reach a depth of about 20 inches. Mine is about 8 inches right now.

Grabbing a ruler to go measure my tiny flow through now.

"Hypothetically, if you could figure out a way they could move downward but not back up, or at least significantly discourage it, then you could let the top tray dry," The dryness is the way to move them downward and not back up.

The cardboard along the sides of the bread trays is just to make you feel better. The worms will avoid the sides because that area will be dryer. The center will vermicompost leaving the outside uncomposted. At least that is what I theorize will happen. It would be really cool to sneak a peek at them at night with a flashlight to see what really happens.

alabamanicole: take a peek at this box. I think it's ideal for a stack system. But ..... they look pricey too.
http://www.pacinj.com/produce_totes.htm

I kinda like the mushroom crates. But no sizes or prices that I can see.

There seems to be a lot of good possibilities in food service... I have no idea how to get in line for the old stuff they are replacing., but I'll keep my ears and eyes open.

Do a google search on key words "plastic cement mixing tub" and you will get quite a few hits. I see one that has a depth of 8" x 37" L x 22" W. Cost $8.00
==
I note that Bently of RWC was using a tub like the one above - http://www.redwormcomposting.com/images/worm-tub.jpg - in a blog post of 10/08 - scroll down to vermicomposting trays - http://www.redwormcomposting.com/2008/10/

Here is a link that might be useful:

I guess I will chime in here. I hesitate to respond to some posts because I have little experience with indoor systems, and in addition to poor vision, my computer and typing skills are awful.
I am on my third experiment with 11" high 13"x13" recycled plastic milk crates. I shove the crate inside of a chirt burlap coffee-bean sack, and fold it back over twice creating a 3 layer burlap wrapped worm house. Worms LOVE these chirt bags, and the weave allows excellent air flow. If I can keep them damp, oxygen should be readily available.
#1) I want to use these easy stacking crates as a flow-thru/ stacking bin system. So far all my wormin' has been outdoors with no heat, in a temperate coastal climate. I started 3 crates during a harvest in January. The cool winter temps kept activity very slow! I abandoned this experiment ( see lack of patience) and started experiment #2 & #3.
Status) I will try again, and maybe adapt it by insulating somehow and/or enclosing it in a box...
#2) I have an unlimited supply of VERY old horse manure, free for the shoveling 1/2 mile away. I call this "magic manure". It has many worms and I believe MANY dormant cocoons. I have fed this to my herd since last summer and have had very good results. I built 4 compost bins last fall out of 3'x 10'x1/2" hardware-cloth creating 3' cylinders. Manure was about 40%of the mix, 20% used coffee grounds, and the rest straw and leaves. Wow did the worms explode! I turned one bin into a worm cage by lining with chirt bags and, after adding about a foot of compost, placed a milk crate bin in the center. I then added another empty milkcrate and filled with bedding kitchen scraps. I then backfilled with wormy compost. This was topped off with a 20 gal tote wormery (1 month old), maybe 10 layers of burlap and 12" of straw.
status: Going well with burlap on top full of worms! I have fed once with 3lbs of kitchen scraps.
#3 I added my other 2 crates into my 3'x5'x18" on the ground worm bin. After I harvested about 75% of my bin, I had room for 4 milk-crates, with room for 2 more after next harvest. I want to create a lateral flow system to make the harvest easier. I want to "herd the herd" around my bin, and pull a crate/month.
I am trying to share what I am observing and learning. This post took me 3 hours. Let me know if you are interested. I love wormin', and have had worms on my brain lately!
Pete

Then you can just reach in and harvest one milk crate of vermicastings at a time. The rest of the crates will be inprocess. I follow.

I like your milk crate experiment #1 design better than what one can purchase. I think it meets the needs of the worms as far as air flow much better. And the price is way better.

Low vision: I do not have a diagnose of low vision but size 8 type is tiny. Here are a few methods I use so I can see things. Maybe you already use them, or know better ones. I would think there would be a switch in Windows to flip to make everything "senior citizen sized" to read. The best I found is holding down the "CTRL" (control button, lower left hand button on the keyboard) and touching the +/= button on the upper right hand side near the letter P, will increase many written parts of a web page one maganitude. If it does not then first click on the page with the mouse. Each CTRL/+ makes it bigger. Each CTRL/- minus makes it smaller. Recently I made the area where I type in addys bigger. I love size 16 type.

For a long post like you wrote even if a good typist I would open a word file. Then I would type the post there saving it frequently then cut and past it to the website. It is so easy to loose a post while typing it to a web site. I relearn that lesson quite a lot.

Many times I try to really see what is going on in a worm bin or with a worm. Nothing like vermicompost or worms two inches away from my face. And still I want to see them clearer.

Eq, low vision= 4 retina detachments (2 in each eye) in a 7 month period. This occurred 2 years ago, 6 months after retirement, and left me with no lense in either eye, glaucoma, and corneal edema in my "good eye".. When the edema clears late in the day, I can focus that good eye to see pretty well and see 20/40. It could be MUCH worse as I was pretty out of focus for 6 months.
Your computer tips are greek to me. I have a rotary dial phone and just began on the computer last year. I do know how to blow-up print and improve the contrast.
I don't want to complain about my condition and will not mention it again. I am just trying to explain my "cloudy observations" some times. I have adapted to my condition well, and now worms make me happy! Thanks for the tips and I will post on my experiments progress.
Pete

I have always been glad to read your posts and found your observations to be spot on and your experiments leading the pack due to your close observation of and pondering over how the worms are reacting to changes.

I have stacking tool bins that I wonder if would work. I would cover the front opening with a solid door and use it to add more bedding, food and then harvest when the worms migrate to the one above it. My question is, is there really enough airflow with only holes in the bottom of the container? and of course with holes in the side of the topmost container?

If you are looking at a system where they migrate up, there's no need at all for a front opening. Just add another stack when the bottom one is almost done, then feed the top.

You will also need airholes in the sides of the containers -- all of them. Roughly speaking, the more air the better, provide you keep the bed moist. Don't worry, the stuff doesn't fall out the sides.