BSF bucket composter v2.1
(click photos to enlarge)
A full function BSF composter
The second generation of the bucket composter features everything needed for efficient BSF composting on a small scale. The surface area of this design is relatively small which means that you won’t be able to use this unit to process large quantities of waste. My main goal for this design is that of an introductory BSF unit which people can use to learn about black soldier fly larvae behavior and about how to keep a colony in balance. I process only a few ounces of waste per day in this unit and under optimal conditions it might handle one pound (.4kg) per day. A few advantages of a small unit is that it can easily be moved as you find the best location, and there is less temptation to overload it with food scraps, something that I believe is a very common mistake. When you’re ready to try a larger unit you can apply the same construction methods on a larger container or use your knowledge of BSF to design your own.
The design is based on a common 5 gallon bucket with lid, and other easy to find hardware items. I limited myself to new materials that I could find in national chain stores, but you can modify the design to take advantage of what you already have or what you can salvage.
The biggest issue with version 2.0 was that the larvae shredded the filter material. I may experiment with ways to make that first filter work, but for v2.1 I’m testing a synthetic material. All the other changes in this version are for the purpose of tweaking performance.
Measurements
I used the American System of measurements for obvious reasons (I live in America) and any conversions to metric are approximate.
The bucket
The bucket I used is made by Encore Plastics but any brand can work. I like this particular bucket because it’s lightweight which makes it easy to cut the various slits and holes. I chose white because it will stay cooler if any direct sunlight hits it, but they do make a nifty green one.
Lid
Snapping the lid in place isn’t convenient when you’re making regular additions of food scraps or if, like me, you enjoy checking on the progress of your colony several times a day. Also, BSF will often lay eggs in and around where the lid meets the bucket so I try not to disturb it too much. For those reasons I don’t snap the lid down, I just let it rest on the bucket. If you have critters (wild or domestic) that might get into the bucket you can make a fastener with two small bungee cords. Simply lay one bungee across the middle of the other bungee to form an “X” shape, and then tie the bottom cord around the top cord with a square knot. Next tie another square knot with the top cord so that the two are joined in the middle. It takes few seconds to fasten all four hooks but the result is fairly secure. I assume it wouldn’t deter a big raccoon, but it might keep the family dog out.
Ventilation
BSF larvae generate a lot of heat as they metabolize food scraps and other waste. Overheating leads to premature crawl-off of juvenile larvae as they try to escape dangerously high temperatures. BSF larvae perish when their body temperature reaches 113ºF (46ºC) and in most climates the composter should be kept away from any direct sunlight. (Those of you who live in cool climates may find that keeping the unit in partial sunshine could help maintain the optimal internal temperature range) The lid vent doubles as a handle for lifting the lid and in v2.0 I expected it would also be used by BSF females as an entrance when looking for egg laying sites, but I never observed this happening. I increased the size of the vent fitting and pipe to 1½ inches. This may encourage the females to use this as an entrance, but the main purpose is to increase ventilation. In this version I drilled 8 holes, 5/8 inches (16mm) in diameter and equally spaced around the circumference. This is an increase from the previous 3/8 inch holes. Then 4 slits are formed using the 4 pairs of holes making sure that the area directly under the bucket handle is left intact so that it can support the weight of the unit when full. (This added ventilation is important in hot climates such as the southeast where I live, but smaller slits may be fine in cool climates such as Seattle and Vancouver.) Keep the slits close to the overhang to help avoid rain water intrusion into the unit.
I used a razor knife to cut the slits but it’s a dangerous operation. The bucket I use is made of fairly soft plastic but your bucket may be heavier and may require a different technique. If you’re not a confident and experienced do-it-yourself type then please get help with this step. You can opt to use only drilled holes as I did in the first bucket composter version. I recommend practicing on a spare bucket before drilling or cutting the one you intend to use.
Lid vent – I increased the size of the pvc pipe from ¾ inches (19mm) to 1½ inches (38mm). The portion of this upper vent located below the lid offers a handy place to affix a strip of corrugated cardboard which is an attractive egg laying substrate for the BSF. Drill a 2 inch (48mm) hole in the lid, again with a hole saw, to accept the short length of pipe that passes through the lid. A short length of 1½ inch pipe passes through the hole in the lid and into the tee fitting above and a 1½ inch connector fitting* below. This pipe should be short enough to allow the two fitting to touch each other so you get a snug fit on both sides of the lid. Use pvc pipe cement to connect the fittings being careful to keep them under pressure for 15-30 seconds for a tight fit. The pipes that extend out horizontally from the tee are cut at a 45º angle to shield the inside from rain intrusion. It’s not necessary to glue the horizontal pipes in place.
*The length of pvc connectors vary by manufacturer. It’s better to use a shorter fitting because it will allow for better ventilation because the opening to the vent will be higher. You can also cut the connector to achieve this but please be careful if you try this.
The photos above are from version 2.1 and below from version 2.0.
Larva barrier
Without some method of containing the larvae they could easily escape via the vent holes whenever condensation is present on the inside of the bucket. Water droplets have surface tension which allows the larvae to stick to, and climb the vertical surface. For the past few years I have had success using Velcro as a barrier. The hook part of the “hook and loop” material is best because larvae sometimes become entangled in the hook side of Velcro. If a larva tries to cross a vertical strip of Velcro the raised surface of the hooks breaks the surface tension of the water and the larva falls back to the compost. The previous version used standard black Velcro and this version uses 1 inch wide (2.5cm) “Ultra Thin” “Sticky Back” Velcro. I’ve also had good results with transparent Velcro which is also pictured below. Both the transparent Velcro and the ultra thin are a different design and seem to have better adhesion than the black. I have seen a few dozen larvae defeat the Velcro, but this is a tiny percentage of the many thousands of larvae that I’ve seen contained by it. Even the commercial BioPod allows the occasional larva to escape. I should mention that it isn’t a big problem if a few larvae escape the unit, but overall we want to contain them so that we can have control over the process.
It’s important when applying the Velcro that the surface of the bucket is dry and free of oil or dirt. I avoid touching the sticky back of the Velcro tape by using the point of a razor knife to hold it while I peel off the backing instead of my fingers. Leave expansion gaps in the Velcro because otherwise the different rates of expansion of the bucket and tape will cause it to pull away from the bucket in places leaving spaces that the larvae might fit through. The gaps I leave are small enough that any medium or larger larvae should be prevented from escaping. The small larvae typically don’t try to migrate out of the unit unless it becomes too hot. Even if you’re careful about installing the tape you may see bumps appear. If that happens use a razor knife to cut the area that popped up and convert it to an expansion gap. If you have a problem with adhesion in a larger section then simply cut it away, clean it with alcohol, and fill the gap with a new piece of tape.
Drainage
The most important function of a BSF composter is that it drain excess liquids quickly and thoroughly. Accumulated liquids will starve the compost of oxygen promoting the growth of undesirable anaerobic bacteria. Anaerobic bacteria thrive in material with little or no oxygen and produce foul, sewer-like odors. A properly designed and managed BSF composter has a pleasant earthy aroma; if you smell bad odors it’s a sign that your colony is out of balance. This drainage system consists of a filter medium, a collection area and a drain tube. You may set up your system to drain into the ground or you may collect the liquids via a threaded adapter and cap on the drain tube when convenient. Some people claim that the liquid resulting from BSF composting has value as a fertilizer but I have not tested that theory. I don’t save the liquid.
Drainage tube – There are many possible variations, but the liquids are drained from this bucket via a ¾ inch (19mm) internal diameter vinyl tube fitted to the bucket with common plumbing fittings. I used about 18 inches (45cm) of tubing which allows the user to set the bucket on a raised platform for draining the liquids into a container for disposal. Alternatively you could use whatever length of tubing required to direct the liquid into the ground or a drain.
Update-July 14, 2010 – Initially I didn’t use clamps to secure the drain tubing to the barbed adapters. After a few weeks of use I find that the connection is becoming loose and I will be adding hose clamps to the fittings on both ends of the drain tube.
In this version the drain is placed as low as possible leaving a little space for tightening the “nut” that holds it. You can mark the center of the outlet hole by setting the fitting in place and holding the bucket up to the light to see where the hole would be centered. A 1 inch hole is drilled and a nylon ¾ inch barb-¾ inch male hose adapter is inserted into it. The tubing slips onto the barbed side of the adapter. The threads on the other end are the same size as those found on the male fittings of common garden hoses. I couldn’t find a nut to fit these threads so I made one out of a threaded plastic cap made for garden hoses. I did this by drilling a large hole in the flat side of the cap. It’s a little tricky to do but the result was a tight fitting nut that holds the adapter firmly in place for a watertight seal. An o-ring slipped onto the adapter threads, on the outside of the bucket, will allow a watertight seal.
Liquid waste holding area – Accumulated liquids need an unobstructed area so that they can flow freely. This is achieved by supporting the filter a few inches above the bottom of the bucket. In this version, as in the last, I’m using plastic practice “golf balls” which are inexpensive and effective. You could use a wide variety of materials to accomplish this but I like the fact that the balls are hollow and perforated so most of the space is utilized for holding the liquid waste away from the filter and compost.
Filter – I’ve used coconut fiber (coir) in the past to filter liquids in my original BioPod. It works well unless the larvae expand it and mix it into the compost. You can use coir but you must find a method for keeping it in place. The previous bucket composter used an air conditioning filter material that is made from hog’s hair. This worked well initially, but it ultimately failed for the same reason most filters fail with BSF; the larvae expanded and shredded it. Whatever material is used, the larvae will tend to congregate in it. As they burrow through the filter they expand the fibers, and after a few weeks of this the filter often loses its effectiveness. Coir or the hog’s hair filter from v2.0 will work fine if a method is found for keeping them intact. I considered sandwiching the filter medium between two discs of galvanized wire hardware cloth. I wanted to avoid using metal for fear of it rusting, but I may experiment with this in the future. For this new version I’m testing a synthetic cut-to-fit air conditioner filter. I don’t have a large colony working in this unit yet, but preliminary results look promising. With this new material I did nothing except cut a single disc to fit the bottom of the bucket about 2 inches (50mm) off of the bottom. Hopefully it will remain intact without modifying it or adding other layers, but you have the option of experimenting with wire cloth (¼ inch or larger) or with “quilting” it with a yarn needle and string.
For a template to shape the filter I used a bowl that was the same diameter as the inside of the bucket about two inches from the bottom, where the filter will be installed. It’s important the filter fit tightly against the wall of the bucket so that food scraps don’t fall through. Too big is better than too small.
UPDATE 7/23/2010 – The filter system I used above gradually failed over a one month period. I believe the modifications needed to resolve the issue are simple. What caused the failure was the effect of the incessant churning action of the larvae. Imagine each individual BSF larvae as a tiny muscle and then multiply that by a colony of many thousand and the collective strength is impressive. I think this filter material will work fine, but it must be contained so that the larvae can’t expand it excessively as they did in the first test. The solution I’ll be testing next is a simple layering of the filter between two rigid meshes. Here I’m using the “egg crate” type panels that are normally used to cover florescent light fixtures in dropped ceilings. Wire mesh (¼ or ½ inch) would also work, but something with small holes like window screen would probably clog too easily. To connect the two rigid pieces I simply tied them together by threading nylon string through the filter with a large yarn needle. I didn’t compress the filter, I just wanted to prevent the larvae from expanding the filter beyond it’s original size.
Optional tap – I also considered ordering a tap like those used on buckets for brewing beer or wine. Those come with a handy nut and gasket and you could probably attach a tube to the outlet for easy dispensing. The only reason I didn’t get one was because it would have added $4-$5 dollars to the cost of the bucket. If you can’t get a water tight seal with the system I used then you might try getting a tap.
Harvest system
Automatic harvesting of the mature larvae is achieved with; a funnel that rests against the bucket wall, which is inserted into a tube, which spirals up to ¾ inch pvc piping, which passes through a hole in the bucket and leads into a collection container. I made the funnel from a generic one gallon plastic water bottle because it is cheap, pliable enough to easily work with and it can be found anywhere. The handle section of the water jug fits snugly inside of the ¾ inch I.D. (internal diameter) vinyl tubing used here. Below the handle section I left portions of two adjacent sides of the bottle which are at right angles from each other. One side will be placed vertically against the bucket wall and the other will be partially buried beneath the compost. As the level of the compost rises the flexible tubing is adjusted accordingly to keep the funnel properly placed at the surface.* Since the funnel and tube will need to be adjusted over time I use a pair of magnets to secure the funnel to the bucket. Magnets can be found at hardware and craft stores. Beware; not all magnets are created equal. It tried using the same size and type magnets from a discount store and they didn’t have nearly the strength as those from the hardware store. Also, I discovered that most Home Depot employees don’t know that they sell magnets. In fact, most of them insisted that they didn’t until I found them myself. They’re in the fastener isle mixed in with the brads. 
*To maintain good harvesting it’s important to check the position of the funnel often. The larvae will constantly move the scraps around and if the opening to the funnel gets covered then the larvae will pass it by and continually circle within the bucket. A larva that enters the funnel and tube isn’t “aware” that it is finding a path out of the unit; it simply encounters the funnel entrance as is crawls. Sometimes small adjustments are necessary to keep the opening at the same elevation that migrating larvae are likely to use, which is normally the surface level of the compost.
The photos should make it fairly simple to see what you need to do for the harvest system. It isn’t really necessary to glue all of the pvc fittings since the parts hold together well due to friction. I do recommend gluing the 90º elbow fitting that is inside the bucket to the short length of ¾ inch pipe that passes through the bucket. I would not glue that same short piece of pipe to the outside elbow so that you will be able to remove the assembly for cleaning or storage, etc. For a harvest container you can use anything that has a water tight lid and if your unit will be protected from rain you really don’t even need a lid. In a dry location you could opt to use only a vertical pipe that enters the harvest container through the top. The purpose of the horizontal pipe is to allow a side entry to minimize rain intrusion. The horizontal pipe is angled slightly upwards as it enters the container so that rainwater will run away from the container and not into it. An inch or two of dry sawdust will serve two purposes; it will quiet the larvae by giving them cover and it keeps the larvae dry so they can’t crawl up the sides of the container.
I don’t give exact measurements for the pvc pipe length because it’s not practical to limit the design to one specific harvest container. Almost any container will work, and if you’ll be keeping your unit sheltered from rain then you can even make a straight drop into the container instead of the right angle I used here. The only reason for the last 90º elbow in the run is that it creates an uphill elevation into the harvest container to channel rain water away from it. It isn’t necessary to glue the pipe together so you can cut the pieces a little long and make gradual adjustments until you get the proper fit.
Conclusion
I’m sure I haven’t included every piece of information possible for constructing this composter, but most of it is common sense if you understand what the goals are. I hope that the photos will supply enough information that might be lacking in the text. This unit is cheap enough to build that you can afford to engage in a little trial and error until you get exactly what you want. There are numerous opportunities to hurt yourself constructing this so please be careful. 
People have requested a shopping list and I will do my best to post one in the next few days.
Questions, comments and updates
I want to be clear that I have not tested this composter yet. I believe it will work fairly well as described above but I expect to make changes as I work with it. If you have questions or suggestions please use the comment box located at the bottom of this page. I’m especially interested in variations on the funnel and tubing that directs the larvae into the collection container.
Follow my progress via youtube:
These videos feature version 2.0
DIY black soldier fly bucket composter – part 1
DIY black soldier fly bucket composter – part 2
BSF bucket composter April 26 2010
BSF bucket after two weeks
No Will, pretty sure those would be just your regular old magots. Kill them with abandon. Otherwise you will have black filth flies.
Sorry!!
Hi Steve and Will,
I know from experience that BSF larvae will populate a garbage can if it isn’t emptied for a longer than average span of time. A can that is emptied twice a week won’t develop BSF because BSF eggs take 4 days to hatch. Even in a can that has garbage in it for a week any BSF larvae that hatch would be very tiny and probably not noticed. I sometimes leave a garbage can full for an extended period of time as a way of monitoring the mating cycles of my local BSF and in my photo gallery I have a shot of several hundred eggs laid on a can liner.
Luckily BSF larvae are pretty easy to identify. If the larvae grow to about 3/4 inches, have distinct ridges and small hair-like bristles, then they’re most likely BSF.
Welcome back Jerry, hope you and your family are well!!
Thanks Steve,
I lost two family members that were an important part of my life in the past few months. I was legal guardian for one and the other was a primary caregiver for my parents. This has kept me busy and also distracted but I hope to start posting regularly again soon.
Oh my goodness, Jerry!! I am so sorry!! My prayers and good wishes are yours!!
Hey Jerry, just wanted to say thanks so much for the helpful tutorial on building this composter bucket. Harvey Ussery put me on to your blog. I’m in the process of making my first one right now. For the problem of ants and other crawly insects, I was thinking of adding a band of tanglefoot around the outside of the bucket, once I finish it and figure out where it’s going to live outside. Should keep most anything out that can’t fly.
Very sorry to hear of your loss this year. My sympathies and good wishes for the new year.
-Kate
Hi Mr.Jerry and all members,
I am from Indonesia a tropical country in Asia.
I already followed and read your blog secretly -lol- for a few months….very nice blog indeed and it always comeup number one in google search.
I already have some big compost heaps and a few smaller composting buckets which all full of bsf larvae.
Problem:
-our environment were full of small house lizard/small gecko which can walk on the wall, so I found that the thing could easily enter the bucket and weak havoc on bsf population, so I put a fish screen on all the bucket holes, the screen is about 2-4milimeters diameter so I guess the larvae which hatch could enter the bucket thru screen and the lizard could not, but -sadly- I observed that the larvae population is downward significantly.
Question:
-do you think my aproach is wrong? I mean should the adult bsf spawn outside the bucket and the larvae just enter screen instictively?
Thank you.
Best regards from Indonesia
-ishady-
Hi ishady,
First, I assume that your buckets will allow BSF larvae to crawl out when the waste is very moist or when there is condensation on the sides of the bucket. That will cause your BSF population to vary and there are also fluctuations in reproduction that are part of natural cycles. I do believe that you’re losing BSF to lizards, but I just want to consider as many factors as we can.
I assume that you understand that reproduction almost always happens outside the composting container. The winged adults mate in flight and female lays eggs near a suitable food source.
Your idea of covering the openings with screen is good. It might be better if you use a size that will allow adult (winged) BSF to enter the bucket, but that will prevent the lizards from entering. 7 or 8 mm screen should be large enough to allow BSF females to enter so they can lay eggs inside. If you use smaller screen the BSF females will lay eggs near the screened openings and the tiny larvae will crawl inside when they hatch, however, you may have better results by allowing the adults to enter. There also may be an advantage of using the smaller screen in that it may help contain the larger larvae, but if you prevent the dark mature larvae from migrating out of the bucket you will be preventing them from pupating, emerging as adults, and mating to increase your local population.
If you have more question please feel free to ask. Good luck!
Hi Mr. Jerry
I am a 14 year old kid and i am trying to build your BSF bucket composter.
As i am a kid, i have limited supplies. I live in California and there isn’t rain for the entire summer to autum. Not even a single drop. So, do i really need the drainage? i dont really have the materials to build one. If i could i would post a few pictures on mine. Thanks for you blog. I really love it
Hi Derek,
Drainage in a black soldier fly composter has very little to do with rainfall, it is necessary because of the liquid released when the larvae process waste. Most food waste has a high percentage of liquid, especially fruits and vegetables. For example, if you add a few pounds of spoiled melon to the composter the larvae will quickly break it down which will release a cup or two of liquid. If you regularly process waste then this liquid will quickly build up in the bottom of the container and create a zone where anaerobic (stinky) bacteria will thrive. Normally the waste in a BSF composter is kept aerated by the churning action of the larvae, but in a flooded container the liquid prevents sufficient oxygen from reaching the bottom.
There is an alternative to a drainage system, but it requires that you regulate the moisture content of the waste you process. You can still add high moisture items, but you would need to absorb the excess liquid by adding dry food waste such as dry grains, cereal, bread, etc. If you keep your composter under a roof of some sort you can also encourage evaporation by leaving the lid off of the unit when possible. Adding sawdust or shavings from non pressure treated wood can also help a little.
Drainage is one of the most problematic issues with BSF composter design, but a well functioning drainage system makes odor-free composting fairly easy to accomplish. One approach you can take is to apply the principles of my drainage system but use other materials that are cheaper. You could probably find cheap material at thrift stores or maybe there are materials around your house that can be sacrificed for the project. If you have a place to set the composter where the liquid waste can safely drain onto the ground you might try making several small holes in the bottom of the unit and layering some type of material to act as a filter on the bottom. My design is only one approach out of an almost infinite number of possibilities.
Please keep in mind that the surface area of a 5 gallon bucket will not support a large BSF colony and that this unit is designed more as a learning tool than one for processing a lot of waste. In any BSF unit it’s best to find a rhythm where, on average, new waste additions are consumed within a day or two. For my bucket design that will usually be only a few ounces of waste per day, not pounds.
Please let us know if you have more questions and I hope you’ll keep us updated on your progress. Good luck!
Thank You Mr. Jerry
Your reply answered my question really well. I dont seem to find ingredients for a filter and so i decided to work on the other parts first hoping that my allowance will build up. I started on the lid. You claimed that you cut the angle of the pipe is because of rain. since there is no rain, i left it flat, is it ok? If it is, i am officially done with the lid. I did add cardboard as you suggested.
hi mr jerry,
Am i annyoning? Anyway, i have a question with the tube for larval harvestation. I see you didnt need anything to keep the tube pushing against the walls of bucket. The pipe i am using do need some support do you have any suggestions? thank you very much for all your help Jerry. My cousin had a compost pile and i found BSFL. They were very fascinating and i did research on them. I have oscars (fish) that are highly carnivourus and i hope that i can harvest these larvae to feed them.
sorry just one last question mr jerry
since i am feeding them to fish, do i need to feed larvae specific things? Will they have bacteria? Will they sicken my fish because of the things i feed? I know they are fed to reptiles.
Derek, I’m here in cali too. I cut the ends straight and it’s fine.
I keep my composter under the back porch so it’s fine. The little buggers are dormant right now so no hurry getting your’s built.
I used a 20 gallon rubbermade storage bin.
Scavenge away!!!
Jerry,
I am currently conducting a vermicomposting pilot using biosolids (human) generated from the wastewater treatment plant I work at. Has there been any research into using BSF on biosolids? Also, as my main goal is volume reduction, what would I do with the larvae if they couldn’t be sold (due to pathogen issues)? Thanks for any insight, facinated by this!
Hi Jerry,
Absolutely fascinating blog and videos. I live in the UK, and currently trying to raise meal worms for chicken feed and already use red-worm (I think this is the name) for composting in worm bins.
I am having trouble raising enough meal worms to make it a practical source of food for my chickens. I started with close to 500 lave, 20 of which pupated successfully and laid eggs. Generation 2 is about half as populous as the initial generation.
Reading down the comments, people seem to be getting fantastic amounts of lave collected, and are reducing down their vegetable waste much faster than my pair of 50 gallon worm composers can manage.
I would go and order some BSFL online now, but I am worried that they would be an invasive species in the south-east of England. Do you know if this is the case, and if so, is there a local species I could use?
Thanks for your time and effort on the blog!
Regards,
Matt
I was able to built a bucket composter and get the BSF colony I ordered to do well to the point where the mature larvae would be captured in a bin and emerge as adults. Unfortunately I didn’t get many adults coming back to lay eggs, so the all-important cycle of life didn’t continue more than a few months. The area I live in is pretty dry and hot, so I’m thinking that the BSF are just not suited to this environment.
As a new experiment, to the old BSF bucket I have added wet, shredded newspaper, a few dozen earthworms, and a bit of food. I’m hoping to get some worm tea out the bottom, some composted material, and perhaps even some earthworms, if they start reproducing. It is too bad about the BSF, but the earthworms seem to be happy!
Yes, flat is fine if your unit is out of the rain. Once you have a drain system that works well a little extra liquid won’t be a problem.
No Derek, you’re not annoying me, but I’ve been busy with other things lately.
The tubing I bought came rolled up on a spool so it was roughly shaped to fit the bucket already. I used disc magnets, four on the inside pulling at four on the outside, as a support for the tube.
Since a fish tank is a relatively small, closed environment it’s wise to be cautious. In a balanced BSF unit there won’t be excessive bacteria because the larvae digest them, if I understand correctly. You might want to avoid feeding the larvae feces and I always recommend not feeding them any meat products that are spoiled or of an unknown origin.
Hi Chris,
Black soldier flies were often called “privy flies” in the days of outhouses. They do very well on a diet of human waste and they’re fairly effective at repelling other fly species once they dominate the pile. I assume the biosolids would be similar and a good medium for BSF. I would probably just release the mature larvae to let them build up the local population. I don’t fear overpopulation by BSF because I feel their numbers would be limited by available food. Good luck and please keep us posted.
Hi Matt,
I’ve only worked with BSF so I can’t recommend another species.
Human movement has already transported BSF around the world so at this point they are free to migrate to anywhere they can survive. What I believe limits that spread is the ability of BSF to survive the cold season and/or the lack of adequate humidity in any particular region. People can support BSF in areas not otherwise able to sustain a wild population, but if that support is removed the BSF will not survive. In a sense BSF have already “invaded” a large part of the world, but have never been reported as “invasive” that I am aware of. In my mind BSF do represent competition to other fly species, but those are the species that have benefited from human activity anyway such as the common housefly. Good luck!
Hi David,
If you had any egg laying in your unit at all then I believe you can increase your local BSF population each year. The heat and lack of humidity shouldn’t be an issue with reproduction. BSF larvae need a moisture level of at least 70% in the waste they inhabit but the adults seem to do fine in dry conditions. In a very dry area you may need to add liquids to the unit, but usually the waste added results in too much liquid making drainage a bigger issue. I’ve heard from several people in hot dry climates who have succeeded with BSF and I think you can too, especially if you’ve had egg laying.
Combining BSF and worms is certainly an appealing idea but it will probably be a high maintenance affair since the two creatures thrive in different environmental conditions.
Please keep us posted on your progress.
Thank you Jerry for your site. It’s very informative. I recently built the BSF bucket composter you designed (very easy btw…with the pictures and descriptions you provided).
I saw that you had issues with the lavae destroying the filter..don’t know if you’ve found a solution yet, but here’s what I did that seems to be working: bottom layer is the practice golf balls (same as the design). on top of that is a circle of hardware cloth cut to size–it kind of scrapes the sides of the bucket as it’s going down, but once it’s in place it holds well. then a circle of window mesh cut to size, then the filter itself. the next layer is a larger circle of mesh. the extra material around the edges folds upwards. this is held in place by a final layer of hardware cloth…this (hopefully) will prevent the larvae from pushing their way down any gaps in the sides.
Again, thanks for this site, I enjoyed reading every bit of it. My chickens will thank you!
Hi Raymondo,
You’re welcome and I’m glad you’re experimenting with this unit. The main problem I see with window screen is that it would be likely to clog easily. I must add that I have never tried using it so if you get a different result please let us know.
Here is the shopping list that I came up with. I haven’t gone to the depot so I sure if Im missing anything.
Materials
5 gallon bucket with lid
two small bungee cords
pvc pipe 1½ inches (38mm)
1½ inch tee fitting
1½ inch pvc connector
¾ inch pvc piping
3 – ¾ inch pvs 90 degree tee fitting
pvc pipe cement
cardboard
rubber band
1 inch wide (2.5cm) “Ultra Thin” “Sticky Back” Velcro
filter medium
¾ inch vinyl tube (18 inches)
hose clamps
2 plastic threaded caps
nylon barb male to hose 3/4″
O ring 1″ OD x 3/4″I.D. x 1/8
practice golf balls
blue filter
braided nylon
plastic crate material
milk gallon
large snap lid container (Tupperware)
pair of magnets
dry sawdust
pet bedding
Tools
razor knife
2 inch hole saw
1 inch hole saw
drill
yarn needle
Hello,
I am thinking about building a BSF composter out of cement blocks and leaving the bottom open and set on sand. I would like the larva to climb out and drop into my chicken coop. I can plant a large tomato plant on the south side to shade it and so I can still open the top to put food scraps in. I have tried to build the bucket verson several times but they never attracted any BSFs. My garbage cans do though. Has anyone ever tried to build one out of concrete?
Elda
Hi Elda,
The bucket doesn’t have any special ability to attract BSF. The females are attracted to the most desirable scent which in your case is from your garbage cans. To attract BSF to the bucket you would need to create an attractive odor inside, like that from your garbage cans, and you would need to remove the desirable scent from the cans. Having said that if you’re attracting BSF to your garbage cans the easiest approach is to simply collect and transfer their eggs to whichever unit you wish to populate. The following link may be helpful and includes information about collecting eggs from garbage cans: http://blacksoldierflyblog.com/2011/05/18/attracting-black-soldier-flies-the-basics/
You can use just about anything to culture BSF but in an ultra basic set up like you describe out of concrete blocks you will have little control over the process. There’s nothing wrong with a simple approach and the least that can result is that you learn more about BSF.
If you want suggestions the best place to get them would be our new forum: http://blacksoldierflyblog.com/forum/
Hi Jerry,
I love your blog and meticulous explanations of how to build the BSF composter! Thank you so much for sharing.
I came across BSFs by accident when I opened up my homemade composter and saw hundreds of swarming mature larvae inside! Perhaps they really multiplied after a week of heavy food scrap disposal. My composter is a 32 gal black plastic garbage can which I cut the bottom 18″ off and sunk the top part into the ground in my backyard. I drilled a few 1/2″ holes up along the sides every 9″ around the can. Drainage is not an issue.
I would love the BSF to keep colonizing in my current composter, so wonder if you have any suggestions to improve it. The composter is in full sun, and I live in Hawaii. I could move it to a different location or simply build a tin roof over it. I thought the BSFs would die from the heat, but they just burrowed themselves down into the bottom of the can where it’s all muddy mush. I drilled a few 1″ holes on the bottom, only to read one of your users comment about the geckos feasting on the flies. I did see a gecko in my composter this morning, so I’ll need to plug up the 1″ holes. I could drill some 1/2″ holes on the top of the lid, for the female flies to get in easier, or try building your T-connector handle, but I’m concerned about the geckos.
Thanks again!
Suzanne
Hi Suzanne,
All you need to do to keep the BSF coming to your composter is to keep adding food scraps. Since the composter doesn’t have a mechanism for containing larvae the population will ebb and flow, but I assume there will always be more eggs laid to replace them in sufficient quantities to see an effect.
The full sun may lower the capacity of your composter to hold BSF larvae so you might experiment with some shading or relocating the unit. Full shade may not be necessary in your climate, but it wouldn’t hurt the BSF either.
For the most part the larvae will be beneath the surface of the waste so your geckos probably won’t decimate the BSF population. Ants, mice, racoons or other animals that may burrow into the waste would be a bigger concern I think.
I would love to hear more about your experience with BSF. It would be great if you registered to our new forum to continue to share and ask questions. http://blacksoldierflyblog.com/forum/
I live in Utah and I’d like to try again to see if I can make the BSF bucket work. I was able to get some grubs to mature to the BSF stage. However, it was very late in the summer and I ran out of warm weather. They never mated. Anybody willing to send me some grubs to get my bucket up and running?
Hi John,
I’m not sure who is selling BSF larvae other than Phoenix Worms which are a bit expensive for your purposes. If you find a good source please let us know.
We have 3, one yard compost bins. Each will sit for 1 year before it is used for the growing season. They are always full of BSF larva, they are fed to the Guinea Fowl as treats. The bucket makes it much easier to collect the larva for feed. Placing it near the bins ensures a ready supply of female BSF.
Hello Jerry
I am going to try the 5 gal. BSF compost it is the only thing I can get my Green Bottle Blues to eat so I hope it works. If you can give me a shopping list that would be grate .
Thank You
Jason
Do you know if the black soilder fly is also native to North Carolina?
Josh there’s an entry for North Carolina on our BSF Locator which is a map displaying the locations of confirmed BSF sightings/populations.
http://blacksoldierflyblog.com/GMap/BSFmap.html
Mike
your fly brooder look simply. does it work? I have found BSF in my worm bins, should I take them out?
Hi jerry, sorry to bother again but i was wondering does their need to be a certain angle to you ramp that the bsf larve go up to? the bio pod plus has one at 40 degrees.
[...] you believe there is a blog called Black Soldier Fly Blog?!?! Sure! This page features a sophisticated DIY specialized composter, with how-to image after [...]
Thanks for all the helpful information! I am building a BSF composter out of an old 1/2 yard rolling tote as part of an Aquaponics demonstration project for the City of Clovis. I have arranged to get the coffee grounds from a local coffee shop. Can BSF live primarily on coffee grounds?
Hi, I used your guide to make a DIY composter, except a larger storage container instead of a 5 gallon bucket. I used the same method for constructing the filter and they burrowed into it immediately. The middle area was already fairly torn up 2 days later. I also used 2 layers and a lot of them had burrowed down to the second layer as well.
Is this normal? it seemed like a lot would get stuck and the filter would get shredded quickly.
I took it out and put the egg crate directly on the bottom and put gravel in. I wait to see if they will be able to borrow into the gravel. I have a feeling if it was just a gravel bottom they could, but the egg crate keeping the gravel packed I feel like they wont be able to borrow the gravel out of the little squares (or try)
Have you ever tried this or do you have any other filter methods you can think of? If this doesn’t work I might just not bother using any sort of filter and let them run into the bottom (with only some filtering around the drain hole)
The only problem I have with both those ideas is if the drain gets clogged it will be hard to service and unclog, having to get them all out then the gravel then unclog it. Maybe it would be better to just wall off the drain hole from the dirt and grubs with something permeable, like the blue filter, since they seem to like burrowing straight down and not so much sideways, maybe ti would be the best of both worlds.
I made a near copy of this composter three weeks ago. Today was the first day mature larvae were harvested. 14 larvae dropped into the outlet container. I fed them to my Tilapia in the aquaponics system. They loved them. I have a few modifications but overall it is virtually the same thing. It works. I live in Nicaragua very tropical here.
I live on Kauai, have a BioPod that has been working great for a month. I got BSF almost immediately. Great chicken food. In the last week blow flies have gotten really bad and it stinks like sewer. I am trying to figure out what I have done wrong and how to fix it. I have a garden so have a lot of waste, I probably have a couple of pounds of kitchen waste a day. Am I putting too much in it? I empty the liquid tea everyday. I’m wondering if I need to let it drain all the time. How often should I clean out the dirt compost, seems like there is a lot now.
Thanks for your blog!
I have a question about using this in places where BSF are not native. We are in NW PA — northern zone 6. I understand I can buy a set of larvae to get started, but how do I keep the population of adults alive to keep repopulating the bucket? Will I need to start over again with new purchased larvae every year?
Thanks!
Hi, I have been trying out my Unique DIY BSF composter for a few months now and have found it very nice. It is unique from what I have seen and I thought it would be good to break the pattern of what people perceive as a workable system…. I also thought it would be a good way to give back to this forum and the people who have inspired me… oh and there is ego involved to
First of all, I would like to thank you for all the information. It is very detailed and I appreciate that.
I live in the US but will be going to the Philippines for a very long visit to setup a farm. I want to raise BSF larvae to feed to chickens and tilapia.
My right hand man can’t read English. I would like to have this page translated to Tagalog. I would like your permission to do the translation. I would like to put the translated page on my web site, WikiHobbyPedia.com. Please contact me via e-mail to discuss this.
Thanks so much!
Bruce
You may translate it.
Well, I have certainly learned a lot here. While I never knew of BSF until stumbling across them on a chicken site I am certain that I have seen them here in western SC. And now I am certain that what I thought was a housefly maggot infestation of my composter (thought a well meaning family member had put meat scraps in there) was probably BSF larva. If memory serves they did seem to be a bit larger than housefly maggots. It is comical that for the BSF we call them larva and for the common housefly we call them maggots – one sounds so much more acceptable. With my new education I will build 2 of the design shown here and locate one on my farm and one at my residential home. Plan on having a dozen laying chickens this spring and intend to feed em to the chickens. Does anyone know what the larva’s life cycle is after it goes to the ground? Does it over winter and emerge the following year as a breeding adult? If not where do the breeding adults come form in the spring?
[...] Click here for instructions about how to make a homemade Balck Soldier Fly Composter! [...]
Thank you, Jerry, for all your information.
I used to get the BSF larvae out of my worm bin and feed it to my beagle, who acted like they were snacks. The dog’s no longer living (old age and having to be put to sleep after an accident), but do you know if there are pathogens within the larvae? Thanks.