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worms4tracy

My new FT Vermicomposter

Worms4Tracy
12 years ago

I started with two pounds of worms and a little VermiHut back in April. Since then, my worm population has exploded and it's getting difficult to 1) feed them from my own household's scraps and 2) maintain both the VermiHut (now using all five trays) and the Rubbermaid 45-gallon tub. I am at the point where I need to start selling worms and harvesting large amounts of compost, so something had to give. Andrew suggested a FT composter and gave some links in my previous post, and I found one that I thought would work really well:

http://vermicomposters.ning.com/profiles/blogs/my-flow-through

I copied this design and built it today. Props to the original designer, and thank you Andrew for the great suggestion! I got a 50 gallon Rubbermaid garbage can with a snap-on lid and wheels, and put in lengths of PVC pipe about 3 inches apart, with 1 1/2" screws protruding about 1 1/4" from the pipe.

I don't get the daily paper, but we have a surplus of brown paper grocery sacks, so I cut those open and put down two layers on top of the pipe, and several inches up the sides. With the overlap, some parts may have had three layers. I poured the contents of three FULL trays from the VermiHut into the bottom, which totaled about 6-8 inches of almost-ready-to-harvest compost, plus a plethora of EF and their cocoons.

On top of that I put about 3-4 inches of bedding: the rest of my coconut coir and a bunch of shredded brown paper bags, cardboard, and junk mail. All of this was damp.

On top of that I put a bunch of food: coffee grounds, veggie peelings and scraps, leftover cooked plain pinto beans, several changes of brown paper from the bottom of the bird cage. All of this had been frozen and then defrosted.

Tomorrow I plan to put a tray in the bottom, shred up a ton more cardboard, and collect a bunch of aged horse manure from a local horse stable that said I can come and take as much as I want.

This whole project took about one and a half hours from start to finish once I got the new bin and the PVC pipe home from the hardware store. Total cost: $66. Tools included a wood saw, a screwdriver, and a power drill with a 7/8" boring bit and a smaller drill bit, all of which I had at home.

My 5 yo helped me put the pipes and screws in. She told me that one of her secret powers is the ability to speak worm and so kept going back and forth between me and the VermiHut to tell the worms how awesome their new home was. :-) She also helped transfer the worms from the VermiHut to the new FT by the very-very-very small handful and insisted on telling each handful that they were about to move into their new home.

I think that to contain my current worm population and allow for their rapid growth, I will need at least three more 50-gallon FT containers. But I am determined that worm sales must pay for them, so I am going to work on that before I head back to the hardware store.

Here are some pics from the project:


By crocpunter at 2011-09-26

My PVC pipe cut to size, drilled with staggered holes on both sides, and fitted with T-joints (for use as a handle). The glue is drying.


By crocpunter at 2011-09-26

This is the bin. It was just wide enough to fit five bars, spaced a little less than 3" apart. I drilled five holes in the front and five in the back about 8" above the ground. I drilled starter holes at the corners of where I wanted my door to be, and then used a wood saw to cut out the shape of the door.


By crocpunter at 2011-09-26

This is what the inside looks like with the holes drilled in front and back, and the door cut out.


By crocpunter at 2011-09-26

This is my 5 yo inside the bin (laying on its side) fitting the pipes and screws together.


By crocpunter at 2011-09-26

This is the inside of the bin after the PVC and screws have been installed. Yes, those are my toes at the bottom peeking through the door.


By crocpunter at 2011-09-26

This is the final completed product. It has a lid that fits tightly.

Comments (15)

  • scotty66
    12 years ago
    last modified: 9 years ago

    i am very interested in the flow through bin, since in theory, it should be the easiest to maintain. I really like the design or you container... did you make air holes in the lid or around the top?

    my main question for this type of design... what prevents the entire contents of the can from spilling out the bottom once you turn the pipes (with screws).

    I understand that the worms at the top layer eating the new food and that the bottom layer is the worm castings we want to harvest... but i imagine that once you start harvesting it, everything will all come down (like an avalanche).

  • Worms4Tracy
    Original Author
    12 years ago
    last modified: 9 years ago

    Hey Scotty, thanks for the questions. I will be the first to tell you that I am not an expert, so I will answer what I can and rely on the real experts in this forum to fill in the rest.

    First, I DID make air holes around the top, but I did them after I took these pictures...when I remembered they were necessary.

    Second, there are two things that prevent everything from spilling downward. Initially, there are two layers of paper grocery sacks (cut open and flattened). My understanding is that by the time the paper sacks disintegrate on their own (several weeks, at least), the contents will have settled and "stabilized" to the point that bits from the bottom can fall out and the rest will remain intact. HOWEVER, since I've only had this bin for three days, I cannot vouch for that. My plan is not to turn the screws that often, only if it appears the VC is really compacted. I really want the compost to drop at its own rate, especially because I want to avoid getting unhatched cocoons in my VC as much as possible.

    Finally, I did make one fatal error that I would share with anyone attempting to make this design. Today I went out to check on my "Worm Hotel" - that's what I'm calling it - and discovered that the bottom had collapsed right around the doorway. The PVC pipes are still intact and the contents are still inside, but it looks like the Leaning Tower of Fetida. I think I cut a "door" that was too big. I believe this can be remedied by propping up the inside with bricks on both sides, but I have to go get some tomorrow to attempt it. I realize that most of the FT bins I saw online were smaller than 50 gallon, or perhaps made of more rigid plastic. I bought the extra tough version of the Rubbermaid garbage bins for sale, but apparently my doorway compromised it. I'll post updated photos tomorrow, if my ego can handle it >.>

  • scotty66
    12 years ago
    last modified: 9 years ago

    bummer about it collapsing/leaning... design looks great and the corners still look beefy.
    I'm guess it collapsed because bulk of the weight is on the pvc pipes... which are also above the opening (where the structure has been compromised). Maybe a redesign with the pvc pipes going from side to side might fix the issue.

  • PRO
    equinoxequinox
    12 years ago
    last modified: 9 years ago

    If you saved the piece you cut out, maybe hotglue it back in place to regain structual stability. Then on the left and right side cut half width size doors. Then to empty the trays pull one from the right side and one from the left side. One tray will be close to the front and the other close to the back. They will run the whole left to right but only cover the front half or the back half. Use the new cut out pieces to also glue on and regain the structual stability of the first design.

  • PeterK2
    12 years ago
    last modified: 9 years ago

    Yeah it's going to weigh a ton once it gets full. I have a 'worm inn' which is much smaller and it's probably close to 75lbs. Rule of thumb for aquariums is 10 lbs per gallon of water. So if you assume wet VC is half that weight, a full 50 gal composter will be 250lbs. But once they eat through the paper and you've got VC, you can harvest to keep the weight down.

    Door on the same side as those pins is a weakness, but would be hard going even on the other side due to the large weight. The bin isn't designed to support weight from the top like that. Trash sits on the bottom with the floor supporting all the weight and the sides just keep it from bulging out. You could fill the bin with water no problem. But put that weight on top of it and it would crumple like paper.

    You could make a box frame to support the bottom. Get some more pipes and make a box (cube) that fits in the bottom of the bin that just sits below those harvesting pipes. Can't be flush with the back wall but it will be on the weak door wall. Then the weight is taken by the havesting pipes and those will rest on the box you made which is on the floor, so you get the original trash bin again with the weight being supported by the floor. If the harvesting pins are not equal height, I'd cut the holes a little bigger so they all rest evenly on the box before it really fills.

    BTW, should work with the harvesting. In my worm inn the hole in the bottom is about the size of a large cantilope and nothing much falls through. I find it's only when stuff gets dry does it fall by itself. So I just leave it open and have a bucket underneath.

    Good luck.

  • sbryce_gw
    12 years ago
    last modified: 9 years ago

    Since I have created a flow through bin with a similar design, I think I will jump in and answer a couple of questions. First, pictures.

    My bin has a harvesting system similar to Worms4Tracy's.

    Since I was concerned about the weight of the VC sitting on the harvesting rods, I decided to start with a PVC frame. I did not think that the bin walls would be strong enough to hold up what I estimate to be about 100 lbs of vermicompost.

    In these first two pics you can get an idea of the approximate size of the bin.

    The bin walls are made from HDPE corrugated plastic (old campaign signs). One thing I learned while making this bin is the there is no adhesive that will hold HDPE. I tried silicone caulking with only slightly successful results. The screws holding the frame in place and the wood frame around the top opening are probably doing more to hold this together than the silicone caulking.

    The walls are double thickness corrugated plastic with the seams in each layer as far as possible from the seams in the other. So far this has held up, though it does bulge a bit.

    Looking down into the finished bin, you can see the harvesting rods in place. I have screws, like Worms4Tracy, but I also screwed in fins of the corrugated plastic. I don't know whether they were necessary. They have held up through a harvesting. One thing I did notice is that they do not allow as much air flow as I think a good flow through should have.

    I lined up the pvc Ts with the fins so that I could tell which way the fins were turned inside the bin.

    Here the fins are turned up.

    OK, observations:

    This bin took a long time to fill up. I would have to do a little digging to determine just how long, but more than a year. Someone feeding a little more aggressively could have filled it up faster.

    The first harvesting worked, but it was hard to turn the rods.

    Now to answer the two questions I want to address:

    > my main question for this type of design... what prevents
    > the entire contents of the can from spilling out the
    > bottom once you turn the pipes (with screws).

    Simply this: The VC packs down pretty tightly in the bin. When you turn the rods, you are literally scraping the bottom layer off of the VC. Everything above that is packed in tight enough that it just won't fall.

    > You could make a box frame to support the bottom.

    Yes, you could, as you can see. I harvested for the first time several days ago, and the VC still has not settled enough to allow a second harvesting. I have even poked at the VC from underneath with my fingers and a letter opener. I cannot loosen up the VC enough to get it to settle. I have tried leaving the fins open for a couple of days to see if the VC would dry out enough to get it to fall. So far, no.

    My guess is that it is the frame that is preventing the VC from settling. Since the VC is a compressed mass, it wants to slide down an unobstructed bin in one big mass. I believe that the frame is preventing that from happening. I was hoping that harvesting would remove most of the VC from the center of the mass, and the rest would collapse under the weight of the VC on top of it. So far, that has not happened.

  • PeterK2
    12 years ago
    last modified: 9 years ago

    Nice setup, and thanks as explaining that box frame in words really had me wondering if the idea would come across. Picture worth a thousand word thing ;).

    I assume those walls are square top to bottom. One thing you could try if you make another is have the walls widen slightly as it goes down. Some of the large scale FT composters I've seen have the advantage of large areas away from the walls so the center can fall through pretty easily.

    With yours and mine, they are more tall and lean which means more wall contact and I guess it plugs up. Even with my dry edges (fabric walls) and drier bottom, I don't get a ton of stuff dropping naturally. Big harvests still require a garden fork.

  • Worms4Tracy
    Original Author
    12 years ago
    last modified: 9 years ago

    I fixed it! Thanks for all the suggestions and pictures. I really liked the idea of redirecting the PVC pipes from side-to-side instead of front-to-back, but I didn't relish the idea of emptying the container to do it. Also, when I really looked at the bin, I could see how the plastic had been so crumpled that simply redirecting the pipes (at this point) wouldn't make the bin stand up straight again. However, for future bins I think it would serve me well.

    I had bought some lumber and bolts to try and make braces on the outside of the container when I saw sbryce's pictures of his internal PVC frame. That was the one I went with. It was a hoot at the hardware store trying to get all the pieces I needed to construct a frame. I had them all spread out on the floor in the plumbing aisle to make sure it would all work the way I wanted and people kept stopping to ask me what kind of crazy sprinkler system I was putting in. Lots of people were really enthused to hear it was for a vermicomposter. In any case, about $30 later, here is the result.

    Here is the crumpled mess that I tilted onto its side so I could examine the damage. The opening is actually bigger than it was, this photo was taken after I tried to pry it open and reshape it with my hands.

    This is the internal frame I designed. The wheels actually take up about half the bottom of the bin, so the frame is only about eight inches deep. I put in an extra central vertical support that you can see at the back of the frame. That ended up being almost dead center of the PVC pipes. The front I left without a central support so that I would still have room to slide a tray in and out.

    You can see in this photo that the PVC pipe and screws are all intact within the bin, that the screws have not rotated at all, and the paper is even still intact. I'm really glad, or the falling compost would have made this job much messier.

    The frame went in in pieces - none of the pipes are glued to the joints. It took a lot of wrassling to get the entire thing in, but in the end the extra-snug fit reshaped the sides and corners of the bin, and the harvesting rods (with the screws in them) rest against the frame, giving them extra support. The rods can still move and spin against the frame.

    This is a picture of the frame completely installed and supporting the bin. So far the whole business has held up, and the worms are still doing fine in there, despite their whole perilous ordeal.

    Thanks again, everybody, for your great suggestions, great questions, and overall moral support. This forum rocks!

  • Worms4Tracy
    Original Author
    12 years ago
    last modified: 9 years ago

    On Wednesday I harvested my first load from my new flow-through harvester, and it worked exactly like I had hoped! I simply turned the PVC "handles" and the screws inside turned and beautiful, black, pure VC came crumbling down. I kept turning, it kept coming. I harvested about 5 gallons, which are now in the process of drying slightly so that I can sift them. When the compost became compacted a little so that the screws no longer reached it, I simply kicked the side of the bin and heard all the compost inside resettle. I opened the lid and the surface of the bedding was exactly six inches lower than it had been a moment before. I can't describe how awesome that experience was. :-D

    Two things I learned:

    1) This compost was pretty full of worms, but I saw very few (if any) cocoons. I am looking forward to sorting out the worms from the VC with my new harvester which I am in the process of building.

    2) The bottom of the bin is not conducive to a tray or any standard-sized receptacle that can catch all the falling compost. The wheels and the internal frame leave an area for a tray that is roughly half the size of surface area of the falling compost. I ended up just taking the tray out and scooping out the compost. For future bins, I think it would be more economical and ergonomic/functional to build a container with perfectly square sides and size it to the collection tray I want to use.

    Overall, however, it worked really well and I am very happy with the results. I think I'm going to call it the Droppings Dropper. Or perhaps the VC Vendor. Or maybe the Push-Me-Pull-Poo? Or perhaps just the Dial-A-Doo.

  • craig1959
    12 years ago
    last modified: 9 years ago

    I will be needing some worms soon, and I would just as soon buy them from someone who is trying to support their habit. Let me know if you are selling them. I am new to this, but have wanted to do it since I was a little kid. Remember the comic book ads "Grow earth worms for fun and profit" I actually sent away for the book. Things have come a long way and this forum is awsome. thanks

  • Worms4Tracy
    Original Author
    12 years ago
    last modified: 9 years ago

    Hi Craig,

    Thanks for your inquiry and it's great to see your enthusiasm for vermicomposting! There's a lot of great information on this forum about getting started.

    This forum is a great place to share information about vermicomposting and what makes it great is the lack of advertising. I would be loathe to try and make a sale in these forums, even if I were in the worm business.

    I would encourage you to look on the internet for worm farms and bait shops near you. Ask your local bait shop who supplies their Red Wigglers (and then confirm that they are Eisenia Fetida). Sites like Craigslist will have local vermicomposters selling them out of their home, and occasionally people of Freecycle are just giving them away. Local farmers markets can also host worm farmers. Most small worm farms are trying to support their habit and love what they do and would appreciate your patronage.

    Let us know how it goes!!

  • craig1959
    12 years ago
    last modified: 9 years ago

    Thank you, I like the idea of talking to a bait shop, and getting the worms locally. I'm sure I'll be on here soon with plenty of questions.

  • 11otis
    12 years ago
    last modified: 9 years ago

    ""When the compost became compacted a little so that the screws no longer reached it, I simply kicked the side of the bin and heard all the compost inside resettle""
    I LOVE THIS.

  • PRO
    equinoxequinox
    12 years ago
    last modified: 9 years ago

    "I simply kicked the side of the bin and heard all the compost inside resettle." Best sentence I have ever read about harvesting a flowthrough.

  • Worms4Tracy
    Original Author
    12 years ago
    last modified: 9 years ago

    Actually, I've started kicking the side of the FT on a regular basis - at least a couple of times a week, even though I'm not harvesting. I can always hear stuff rattle around and re-settle when I kick it, so I figure it's keeping things loose in there So far, so good.