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Continuous Flow Bins Intro & Reviews |
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Written by Administrator
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Sunday, 11 September 2005 |
During his time as the director of the Rothamstead Agricultural
Research Station in Great Britain, Dr. Clive Edwards developed a
vermicomposting system design that eliminated the labor- and
time-intensive task of separating worms from the finished material.
Referring to the design as "continuous flow," his method is commonly
used for medium- to large-scale vermiprocessing systems around the
world. In the last few years several manufacturers have generated
home-scale vermicomposters based on Edwards' continuous flow concept
and these systems are becoming increasingly popular.
Continuous flow bins are relatively deep containers with raised floors
made from widely spaced welded wires. The system is generally bedded by
laying several sheets of newspaper over the wire floor, on top of which
is spread roughly six inches of damp bedding. The newspaper sheets,
which eventually decompose, serve to prevent bedding from initially
falling through the floor until the worms have had an opportunity to
work through it. Worms are added to the system and food waste is added
gradually, layered with bedding material, just the same as in the
top-feeding method of system management. The system is continually fed
until the bin is nearly full. The worms move upward through the
feedstock/bedding layers. When fed at the appropriate rate, they
concentrate some four inches below the surface, where microbial
activity is highest. If the system is overfed, the worms will spread
throughout the bin material, reducing the efficiency of the system.
Once the bin is nearly full of material, vermicompost is removed from
the bottom each time the system is fed, establishing an equilibrium.
Some continuous flow systems have a metal bar that sits on top of the
wire floor. Vermicompost is removed by pulling the bar across the
floor, which causes a thin layer of vermicompost to fall through. Some
systems suggest scraping a small rake across the bottom of the floor to
dislodge the vermicompost.
Possible challenges to continuous flow systems
Cavitation:
Castings need to remain in contact, or a very short distance above, the
grate for harvesting to work correctly. Sometimes the vermicompost's
conditions cause it to stick together, away from that grate. This can
often happen when the system is drier than recommended. The user needs
to learn to adjust the system's moisture well.
Advantages of continuous flow systems
Ease of Use
These systems accept feedstock from the top of the bin, at a height
that is convenient for many users. Continuous flow designs enable the
user to remove finished material from the system without having to
remove the vermicompost and separate it from the worms.
Continuous Flow Bins
The Worm Swag
pecifications:
The Swag Includes:
- Heavy-duty fabric
- Fitted cover
- 2.0 ft2 surface area
Worm SwagTM review:
by Sabala
The Worm Swag vermicomposter looks like a huge basketball hoop, with
its dark green plastic sack hanging from a sling in place of a net. A
string allows you to tie the bottom closed easily, then, when you
release it, it opens up the short cylinder-shaped bottom of the sack
for harvesting. I haven’t harvested castings from the Swag yet, but the
picture reminds me of milking a cow! You squeeze this short cylinder
(the tit) to let the castings drop through.
I set up the Worm Swag on November 27th last year in the basement of my
house in San Francisco. It can be hung from a tree or under a porch,
but the instructions say it can weigh as much as 100 Kg (220 lbs.) and
I don’t have a tree suitable for that. So, I set it up on a stand,
which was easy to assemble.
According to the directions, you put at least a bucketful of castings,
coir or finished compost and the worms into the Swag. Then, you place
the cardboard disk that comes with it on top. I placed a pound of worm
castings in first, and then a bucketful of coir. I inoculated with
worms from my Wriggly WranchTM. Then, I added about 1/3 or 1/4 of the
material from the top tray of my bin. Because this is from an active
worm bin, it included worms, undecomposed food waste and castings. I
also put a lot of hand-shredded newspaper under the cardboard. I placed
a bucket under the Worm Swag to catch the excess water that drips
through the bottom. (Because the plastic sack is sturdy and thick,
water drips through even if you tie the string tightly.)
Because I was interested in how much waste the Worm Swag could process,
I put increasing amounts of food waste in every month. I also put some
rice bran in to raise the temperature. I never chopped my own food
waste to feed the worms. As time passed by, I needed extra food waste
to continue the experiment and I got it from an organic grocery store.
When I had whole apples and pears, I chopped them into big-bite-sized
pieces. This was by no means a scientific experiment. I don’t know how
many worms I had when I started and I didn’t keep a record of the
temperature. Whenever I fed the worms, I turned the bedding with a
garden fork, and added newspaper and water.
December, 2000: I fed a total of 11 lbs. (5.1kg) in 6 feedings plus 1 lb. (450g) of rice bran.
January, 2001: I fed 34.6 lbs. (15.7kg ) in 15 feedings, plus 2 lbs. (900g) of rice bran.
Feb. 1-Feb. 19: I fed 57 lbs. (25.8kg in 11 feedings, plus 1.05 lbs. (480g) of rice bran.
I stopped feeding the Swag because it started to smell bad. At the same
time, I became very busy and neglected it for two weeks and then found
that most of the worms were gone. I think I could have revived the Swag
if I had kept adding newspaper and turned it every other day or so.
Compared to my other worm bin, the Wriggly Wranch, the Worm Swag tends
to be dry. The lid of my Wriggly Wranch is plastic with some aeration
holes. The water that evaporates in the bin will hit the lid and drop
back into the system. The Worm Swag also has a lid, but it is a tightly
woven nylon mesh. Usually the bottom of the cardboard disk on top is
somewhat moist, but the upper side is dry. I wet the bedding with a
spray bottle whenever I added food waste.
Right now, my Worm Swag is in the recovery stage. I inoculated with
some more worms to let them process the smelly material, which is
almost all gone now. The Swag is about ready toprocess food waste
regularly again. I like the Worm Swag very much because it processes a
lot of food waste (unless overfed), and harvesting the castings seems
to be very easy.
According to the dictionary, the term Swag means "a hanging bundle."
The Earth Factory
Specifications:
- 18" x 23" x 22"H (compost chamber)
- 46cm x 58cm x 56cm
- 2.9 ft2 area
- Stands 32" (81cm) from floor to top.
Bin comes with:
- 10-page instruction manual
- Harvesting tray and redwood lid
Worm Digest comments:
This company has just created this simple to
operate, attractive-looking continuous flow vermicomposter. Its green,
recycled plastic sides are held in a very sturdy welded tubular steel
frame, which is powder-coat painted. The very nicely fitting lid is
also made of attractive recycled redwood.
Though our staff has not had the opportunity to use one over an
extended period of time, we have seen it in use and our impression is
very good. Its size should give it the ability to handle a good amount
of waste and, at 32" high, the unit feels very easy to work with.
Once the system reaches the "full" mark, harvesting is accomplished by
moving the handle back and forth. The tray below is designed to receive
the castings thus dislodged and to catch any liquid that might drip
through during daily operation.
The Earth FactoryTM is the most recent addition to
EPM's flow-through systems and the one designed for household use in
mind. The unit looks good and should work very well indoors or out.
EPM, Inc. is also the manufacturer of several large flow-through worm
bin systems.
The EliminatorTM
Specifications:
EliminatorTM 300
- 16" x 13.5" x 18"H (compost chamber)
- 41cm x 34cm x 46cm
- 1.5 ft2 area
EliminatorTM 600
- 19" x 25" x 18"H
- 48cm x 64cm x 46cm
- 3.3 ft2area
Note: The larger (Eliminator 600) model has been discontinued.
Both models stand 36" high.
Bins come with:
- 3-pound bag of vermicompost
- Coconut fiber "coir" bedding block
- User's guide
EliminatorTM review:
by Kelly Slocum
I received my Eliminator from the Happy D Ranch Worm Farm in July of
this year. The unit was mailed completely intact and required no
assembly; a fact that I appreciated greatly! The vermicompost
collection tray and coir brick that came with it were packed neatly
inside the unit and the worms were mailed separately once I had
confirmed that I received the EliminatorTM.
Even though the unit shipped to me was, by agreement with Happy D
Ranch, a prototype, my first impression was very good. The unit stands
tall enough that I need not stoop to feed, is an attractive natural,
unfinished wood box built on galvanized steel legs, and is very sturdy.
I've stood on it on more than one occasion to clean leaves from my
gutters!
There were no instructions with my unit as it was a prototype, but
support from the folks at Happy D Ranch left me with no questions. I
set the Eliminator on my patio in the shade of a holly tree and under
the eaves on the east side of my house to protect it from our Pacific
Northwest rains. The climate in this part of the US is very mild with
summer temps rarely reaching above 90 °F and winter temps rarely
dipping below 30 °F.
As per instructions during a phone conversation with Happy D Ranch, I
began the system using the standard practice for all continuous flow
systems; several sheets of newspaper laid on top of the welded wire bin
floor and covered with the dampened bedding, in this case the coir
fiber supplied. Once my worms, 2 lbs. of Eisenia fetida, arrived I put
them on the dampened coir bedding and covered the surface with roughly
1" of food scraps from my kitchen. This amounted to roughly 3 pounds
(approximately 3 cups) of feedstock. I spread 2" of damp, shredded
paper over the food waste and left the worms to explore their new home.
I next fed the system five days later, when the worms were actively in
the previously added feedstock, by again layering 1-2" of food scraps
with 1-2" of shredded paper. I was able to feed the system roughly
three cups of feedstock every five days for the first couple of weeks,
then activity levels began to increase dramatically. After 20 days I
was feeding three cups of feedstock every three days and, by the time I
had been managing the system for 6 weeks, was feeding three cups of
feedstock every other day consistently.
My Eliminator was filled to within a few inches of the top of the unit
in roughly ten weeks, at which time I began harvesting each time I
added new feedstock. The first time I pulled the harvesting bar to
release the castings I found it a bit difficult to move. I had to brace
against the side of the bin to get enough leverage to tug it out. Once
the bar was released with that first pull, however, I had no problem
moving it back and forth several times. I harvested until I had about
2" of vermicompost in the collection tray beneath the welded wire floor
and was pleased to find no worms and no recognizable organic material
in the vermicompost. I also noticed that the working column of material
in the bin had not shifted down to rest on the welded wire, but by the
next morning the contents had settled and the bin contents were once
again in contact with the wire floor. Subsequent harvestings did
produce a few worms coming from the bottom of the unit with the
finished material, but their numbers were so few that they were easily
picked out in a moment or two or simply left in the material. I found
no cocoons in any of the vermicompost I harvested from my Eliminator.
I like this unit very much! I find it attractive and simple to manage
and harvest. For beginners to veterans, this unit is a winner!
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Last Updated ( Sunday, 02 October 2005 )
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