The Worm-A-Rater





Introduction: The Worm-A-Rater

Get in the Garden Contest

Finalist in the
Get in the Garden Contest

Having a vegetarian wife means we produce a whole lot of bio-waste. We decided to try our hand at organic gardening and that led me to vermi-posting (using worms to produce compost ). I started out with just a simple plastic box but soon found that we were producing more than the box would hold and the worms just did not seem happy. they tended to congregate on top of the bedding. After doing some research I realized that my worm bedding was to damp and way to hot for the worms liking. This was in early March and the temps here in north Texas were still quite pleasant. In the heat of the summer we will have temps in the 100 degree range and that is sure death for my wiggly little friends. If I was to save the worms from a cruel death by baking a solution was needed and the wife was certainly not going to allow those things in the house! Oh what to do?! Eureka!

Step 1: Enter the Worm Hotel

I just happened to find a very large discarded ice chest that was easily three times as large as the first box.
AS the worms digest the bio mass there quite a bit of liquid produced that must be drained to help keep the bedding dry. This worm juice is also a very rich fertilizer and I want to catch as much of it as I can so I constructed a simple stand from scrap lumber to elevate the box 14". Using a 2" hole saw I bored a hole through the bottom on one end and inserted a 2" PVC floor drain fitting and attached a 6" PVC tail. A bucket is placed under the tail to capture this wonderful liquid gold. (just don't smell it!) A 3"x3" piece of landscape fabric is siliconed over the inside opening to prevent a worm exidous into the bucket. A slight pitch was later added to the stand to ensure that the liquid drains properly.
Good air flow is also needed for happy worms so I bored a 2 1/2" hole in the lid and inserted a 2" PVC T using silicone to secure it in place. covered the inside with paint filter mesh to keep the bugs out. This allows warm moist air to rise and exit the box. For air intake I drilled 10 1/4" holes in the front with a paddle bit and framed around the openings with a yard stick. The same paint filter mesh was used to cover these holes as well. The mesh serves to keep the flys and other bugs out.
Success! I was once again blessed with happy worms producing what worms produce and doing it at a very rapid pace, for about 3 weeks then once again Worm Strike!
I found that the compost was heating up to the point that the worms wanted out. Here is where the story gets weird, after all why would some one really care about a bunch of worms going on strike because of unfavorable work conditions.
Well I consider myself to be a fair and reasonable worm manager and promised the worm union a solution to these deplorable composting conditions, they agreed to work even harder if a solution was provided. So I consulted with all the experts in HVAC and refridigeration that I know (exactly none) And found no solutions being offered so here is what I did.....

Step 2: Get the Heat Out!

Thinking about geo-thermal systems I realized that by simply circulating cool water through the inside of the box and out into a bucket I could pull a lot of the heat from the compost.

I just happened to have 12 foot of 3/8 copper tubing left over from another project that was formed into a coil that would fit inside the box with one end projecting through a hole drilled into one end.
The tubing spirals down and around three times and exits through another hole in the same end.
Poly tubing is attached to the copper pipe and connects to a small fountain pump on the upper and and a manufactured spray head on the lower. A five gallon bucket sits below the nozzle, in the bucket is the small pump. SUCCESS! compost temps dropped back to a level that the worm union was more than happy with. (78 degrees)

Step 3: A Breath of Fresh Air

To further improve ventilation in the Worm-A-Rated Hotel I added a small dc fan connected to a discarded solar cell that was used to power landscaping lights that died. The little fan kicks on after the sun goes down and pulls in the cooler night air further cooling the box.
The worm union is so happy they are now producing over a gallon of "Worm Juice" per week!

I hope you enjoyed reading about my wormy adventure as much as I enjoyed solving the challenges.




    • Science of Cooking

      Science of Cooking
    • Trash to Treasure

      Trash to Treasure
    • Paper Contest 2018

      Paper Contest 2018

    We have a be nice policy.
    Please be positive and constructive.




    Thanks for this Instructable. I have lost all of my worms in both of the last two summers here in South Australia. Worms are not cheap to buy IMHO, and even so, I have to wait at least three months to dodge the heat waves we get here, before buying the next lot. A friend has a fairly large worm farm, but this summer that has just ended, saw his all die as well. This has led me to dreaming up ideas of double or triple dairy cream bucket designs, so that I could ensure that a small amount of worms could be saved in the old beer fridge. I will try to work a way around this design of yours, and see what I can find at the tip. LOL

    Very clever instructable, and very clearly presented. I bought my starter herd while visiting my daughter in CA, smuggled them home in my luggage, and put them to bed outside under a tree. I'm in the Dallas, TX area, where we had more cold than usual last winter and more heat this summer. It's been in the 100s for days now. My worms spent the winter in a styrofoam box outdoors in the corner of the porch. I drilled holes in the lid and stapled window screen fabric inside to provide air, curtail elopement and prevent intruders. They survived the snows and, to my amazement, were still alive in the spring. I moved them into a hard plastic storage box with a top that closes like clasped fingers. The box sits on an expanded steel table with an umbrella in the center. It's next to the house, so it's shaded by the roof overhang on one side and the collapsed umbrella (somewhat) on the other. Not much sun. Home Depot sells some little little 1" louvered vents, which I installed on both sides, using a hole saw to make the openings. At one end, at the bottom, I drilled another hole and installed a spigot for draining off the worm tea. I use shredded newspaper for the bedding, and some corrugated box material or that pulpy material used for packing apples and oranges for the top layer. It's free at the grocery store. I add vegetable scraps at the top, lifting the box or newspapers or pulpy layer and placing the feast on first one side and then another. They have stayed alive without air conditioning or a heat pump, but I do think your ideas sound exciting. I tend to be rather frugal with my efforts, and haven't tried to care for their comfort, except to keep them alive. They seem to be reproducing rapidly, wiggling enthusiastically and creating black gold for my flowers. My kids and older grandkids have no interest and think Grandmother is a bit strange for having a worm farm, but I can live with that. Maybe the 4yo grandson will be interested. He likes to play with the water hose outside, just watering plants and himself. BTW, the table and umbrella and styrofoam box came from the "curbside variety store" the day before garbage pickup, so I'd call them "green". Keep on vermicomposting!!

    If the components in your solar fan are standard off the shelf electronic parts, Such as from radio shack. Then you can alter the circuit, To make it turn on in the daytime when its the hottest. And then it would just sit all night long gathering whatever little light it can until morning. Also the capacitors could most likely be replaced with larger value capacitors, That would store enough energy to give it the kick start that it needs when it first turns on, So you dont have to tap it anymore. Or it could all be in a microchip which would make this suggestion pointless. An alternative idea, Is to use a relay that is normally on, And when its powered it turns off the power to the fan, And just wire your fan through this relay, So that its on in the daytime, and off at night.

    I like it...I have an old cooler in garage that is now destined to become a worm hotel.  I'm thinking of maybe taking the radiator from a discarded fridge and shaping into the bed.  What do you think?   I will also, since living in the Chicago area need to be able to survive below freezing temps in the winter.

    This is a great instructable. I have been thinking about making one of these for myself, and this provides a great starting point. The only thing I'm not thrilled about is the fountain pump. It would be nicer to come up with a "greener" solution. One could get a large solar panel to run the fountain pump, but large solar panels don't come cheep. It seems to me that a better solution might be evaporation. This is not my area of expertise so I'm not sure how it would be done. I imagine a piece of cloth wicking up water, which then evaporates cooling a conduit, then the cooled air in the conduit could be blown by a solar fan into the worm hotel. Anyone with expertise here please chime in. Am I totally off base or can this be made to work? Great work COOPDADDI and thanks for sharing!

    What about a distillation sort of setup? The water at the bottom could be heated by a solar oven or the PVC pipe spray-painted black. The evaporated water would rise back up the original elevation where it could be condensed. The cooler water in the original container would absorb the heat from the soil and sunlight.

    It works in theory.....

    I agree that a greener solution would be better. I have purchased a solar fountain pump that works great when there is direct sunlight, but stops when a cloud passes by. The set up did not include any type of battery storage it is a direct power set up so I have been experimenting with with a couple of different options and will update when I have something workable.

    Glad to read that, because I was concerned that this compost was counter-productive if it required the use of electricity every day. I would imagine that you could find a way to make the fan solar powered too, making this composter completely green.... even though it is technically brown and smelly.

    the fan is already solar powered

    what about a rain barrel