Backyard Aquaponics
A place to discuss aquaponics

There tends to be a big fascination in the AP world with BSF and a lot of effort goes into growing this fantastic food source which is free, full of good fats and high levels of protein and other essential amino acids. If you live in a cooler climate though, which equates to anywhere in Australia where winter temperatures drop below 20 degrees Celsius, the breeding and regular supply of BSF decreases dramatically. This makes providing a supplemental feed frustrating, sporadical, and inconsistent during the cooler months.

However, what is largely overlooked (and often considered a pest in BSF collection buckets) is that of the maggot from the house fly Musca Domestica.

House fly maggots can be successfully bred all year round, at close to 0 degree Celsius temperatures, with very little effort, and in numbers that will often out produce BSF quantities considerably gram for gram vs time. Additionally, the maggots can be used in fingerlings at a much smaller size than that of BSF which equate to on average a 7 - 9mm feed pellet.

Indeed, there is big interest and research into the House Fly maggot being bred for commercial feed supplementation (and replacement) in the Aquaculture industry overseas as the demands on the oceans biomass continues to increase and becomes an ever drained resource. The result is that as resources decrease the price of producing feed rises.. Other alternative protein sources such as soybean meal are gaining more research ground as it has been possible to replace 80% of fish meal with soybean. All in all, these factors are likely to have a large scale impact on Aquaculture in the future, and Aquaponics.

For the AP enthusiast, as the price of fish meal increases, the potential is that it may cause some to consider the value of their project, or to not start one in the first place.

So, where do we turn for a cheap well rounded fish feed that is sustainable? Can be fed to young fish, is free, and can be produced all year round.?

Musta Domestica...!

The Biopod is something that nearly all AP enthusiasts are familiar with for production Black Soldier Fly (BSF). When the weather warms they are fantastic little production power houses for producing free feed from vegetable scraps.

Unfortunately, no one bothered to tell me before I purchased mine that you really do need to live somewhere much warmer than Tasmania for them to be at all effective. After 3 summers of trying hard as I might, the best I could ever produce was a handful of BSF before the weather changed and all I had was a festering mess of anaerobic scraps.

What I did begin to notice however, was that the bucket was regularly contaminated with house fly maggots (HFLM) and the fish went ballistic over them.

So, just as the Biopod was about to be listed for sale and given up as a bad joke, out went the vegetable scraps and in went some meat scraps and fish frames as a 'trial'. The biopod was also moved to the corner of the yard furthest from the house "just in case"

Not much happened for a few days and certainly there was not much of a smell at all.. Then whammo, one morning I had a solid amount of HFLM in the bottom of the bucket.

And I started researching the humble house fly.. Its a weird passion now but someone has to do it...

i like your thinking
could be a good winter food source for wa too?

Great work Tony and definitely a good way to go with your weather situation.

And they make damn good fish bait as well ...

I'm assuming they self harvest like the BSF? Obviously that was a big advantage of the BSF, but if other larvae do it it's a moot point.

What about the disease factor? Does that not apply to larvae?

They sure do self harvest.... Like clockwork..

A mate of mine is a microbiologist and assures me that the digestive processes in the HFLM pretty much will rule out any pathologic disease such as worm larvae that may be in the roadkill or other meat products.

And the purpose of the flour is to let them flush out any digestion continuing from the Biopod contents. A bit like cleaning out Snails before throwing them in the fry pan...

And I then us an old metal colander to quickly wash down the larvae of flour and any excrement before putting them into the tank..

The use of HFLM protein for poultry and fish production has been widely reported in the scientific literature. However, different authors have reported different nutritional values for maggot meal and some of which were attributed to variations in species, age, method of processing and source of the maggot.

Musca domestica is probably the most efficient breeder of maggots with high crude protein content that has been reported to be around 43 - 67% dependant on drying processes used in the study design.

Either way, HFLM presents with high levels of protein, and the amino acid profile of maggot meal contains 17 amino acids among which are nine essential amino acids. The most limiting essential amino acids, lysine and methionine have been found to be higher in maggot meal when compared with those of other conventional protein sources including fish meal.

Interestingly, data on BSF maggot analysis is quite scant. If anyone has any, let me know so I can add it to a spread sheet in the making comparing BSF, HFLM, Soybean Meal, and Fish Meal.

Wow, that's great to know. I was planning on getting in to BSF larvae (don't have an AP system yet, but thought it would be a great way to compost EVERYTHING.) I do know there are some BSF in the area, but they are few and far between. House Flys are more regular (as in most locations) and my climate isn't ideal for BSF. We do have bats though, and a lot of robins, so I could feed them in maggot form to the robins or let nature take its course and let the bats get them (when they return next spring - hopefully.) My wife and I have just over 2 acres, so I could easily put this towards the back property line and it wouldn't be a nuissance.

Do you have any idea if house flys are attracted to the scent of their own pupae like BSF are? Obviously we wouldn't want an increase of house flys in our house, but certainly feeding the maggots to birds could possibly decrease the over all number of house flys if most lay eggs solely in this system. Of course, house flys live for about 30 days, so they do more than mate/lay eggs like the BSF, but it could still work on some level I suppose.

what about slaters , I have some trout in a pond (Non AP as yet) and the go absolutely nuts for a handfull of slaters ?

The redfin go nuts over slaters too but it is a bit time consuming seperating them from the trash.There would be more slaters than worms in the worm bed.

Can someone tell me what this means? is there some way to filter them from the crud they feed on? I know if you hang a dead thing over a potential fishing spot maggots drop into the water at a steady rate but I dont need dead things hanging all over the yard or at least I dont need any MORE dead things hanging over the yard (my wife's a hobbyist necromancer*)

Also... what are they eating. I would have thought they ate meat. And if so I would have thought it might just be better to feed the fish the meat. Did Newton write a law on the conservation of protein?

I'd love to grow some.


*actual reality may differ from that depicted

Can someone tell me what the self harvesting bit means? is there some way to filter black soldier fly or house fly larva from the crud they feed on? I know if you hang a dead thing over a potential fishing spot maggots drop into the water at a steady rate but I dont need dead things hanging all over the yard, or at least I dont need any MORE dead things hanging over the yard (my wife's a hobbyist necromancer*)

I always assumed the bait sellers that collected my maggots did so with with a sieve and a clothes peg on their nose.

Also... what are the house fly larva eating. I would have thought they ate meat. And if so I would have thought it might just be better to feed the fish the meat. Did Newton write a law on the conservation of protein?

I'd love to grow some.


*actual reality may differ from that depicted

Although I'm no expert, I will give you the general idea of self harvesting BSF and HFLM.

If you look up the biopod they will surely explain this better, but basically it is a big bucket that you put scraps in. Any organic matter can be put in here as far as I can tell. This includes fat and grease that you would normally like to keep out of a conventional compost pile. The maggots feed on these organic materials until they are ready to become whatever fly they are destined to be. At this point they decide there is a better location to make their transformation, so they begin crawling away from the central location of their brethren. In the biopod example, this means they hit the wall of the bucket, but continue moving until they hit a ramp. As long as the ramp isn't too steep (not sure of the angle, but I believe 45 degrees is ok) and there is some moisture for traction, the pupae will climb up this ramp. At the top of the ramp there is a hole that leaves the biopod. Instead of finding safety, the pupae falls down a tube that ends in some sort of smaller container where the pupae sit and wait for whatever you deem is there next life action.

The biopod is a great idea, although rather expensive. If you go to blacksoldierflyblog.com there are instructions on how to create your own self harvesting pod. I'm sure some of that didn't make sense, but I hope you get the general idea. I haven't heard of the flour technique that was written about but it makes perfect sense.

Perfect explanation Bob.!!!

I will over the next few days post a heap of images showing the Biopod in action.

Here in TAS we are blessed (sadly) with regular roadkill. Possums and wallabies make up the bulk of the carcasses found on the side of the road.

But I now regularly stop and pick up the fresh ones to keep a steady supply of meat in the Biopod. The major concern people have with this is smell. HFLM however only consume dead flesh. That is, the cause of smell is the cellular structure of the carcass breaking down which is exactly what the HFLM eat and hence very little smell

To date I have tried:
Roadkill
Fish frames
Abalone shells/foot
Pigs heads
Chicken Necks
Butcher scraps (stuff they can't sell)

Whilst highly productive, I do not recommend fish frames and seafood scraps unless the pod is a good 30m from the house. They DO pong a bit and the maggots crawl out with a quite wet and anaerobic slime. But this is easily washed off with the flour and the maggots are fat little suckers.!

As for a container, as Bob mentioned there are a number of designs out there. You don't need to shell out money for one. They are easily constructed. I just had a Biopod no longer being used.