Backyard Aquaponics
A place to discuss aquaponics

So, a few weeks ago, I never knew what a Black Soldier Fly was. I heard about them on a podcast. When I Googled those amazing little insects, I realized that I have seen them before but thought they were some kind of wasp.

I had and idea, based on many other's ideas, for a composter/harvester. I went to my garage to see what I had available that wasn't serving much of a purpose. I found this bin.
It had 3 drawers but was easily converted to 2.

I used a single length of 1 1/2" pvc. Cut it about 3/4 of the way through and then removed the the top half of the remainder on the bandsaw. I then bent it at the first cut and I had a very easy to make ramp. I cut a hole in the top drawer and mounted 2 cottage cheese containers, one smaller than the other, below the hole. The inside container has tiny holes to drain any fluids into the larger container. (Just in case.)

The top drawer also has a lot of tiny holes for drainage that will collect in the bottom drawer. I can use those fluids as fertilizer.

It is not very big so if it works, I will consider using the file cabinet sized bin that I have.

It only took me about 1/2 hour to construct the composter. I will keep you posted on the success or failure of my system.

I will be watching with much interest!

Same here Ron.

How are you going with the composer? I'm keen to hear how this is going? I'd like to try this as well for my new system and I was considering either buying or making a one.

I just put it outside with some food scraps yesterday. I plan to wait a week or so to see if I get any BSF larvae. If not, I may just buy some larvae to get it started. I will keep you posted.

I would suggest that you push the ramp over to the side of the bin. the BSF tend to crawl till they hit a wall, then follow the wall round and round.. They may miss the start of your ramp totally following the wall.

Good suggestion, thank you. The shape of the bin doesn't allow for a collection cup to sit under the hole if the ramp is on the side. I will have to see if they have trouble finding their way out. If so, I will try moving it to the side and adding a "deflection ramp" to deflect the falling BSF larvae into the cup.

Time will tell. First, I need some BSF's. LOL

I returned from a 3-day trip yesterday. There was lots of activity in my test bin. I have at the very least, housefly maggots and fruit fly maggots. There are so many larvae in the bin that I can't be sure if any of them are BSFL. I am pretty sure that I spotted some that had orange coloring near there heads and had "ridges" on the body but not as discernible as some of the pictures I have seen.

I figure that I will know for sure in another day or two. If no luck, I will buy some online. I really don't like the idea of breeding two fly species that I despise! Come on BSF! LOL

Upon further thought, I think I could simply rotate the ramp and trim off one edge so that it sits up against the side. That might work if they need help finding their way.

Thats sounds like an easy fix. Another option could be to use a rubber hose or something and curl it from the side up to the spout?

So I went out there to further inspect the situation. There were about 1,000 common houseflies in and around the bin. I am ordering some BSF larvae right now and am going to destroy the colony that is now growing. The last thing I need or want is more of those little buggers.

Thanks for doing this. You've found a way that doesn't work, and saved me from doing the same mistake. I was planning to do the same until I read this.

i'm still trying to get mine going, it is going but only just, i think the cold weather makes it hard to get plenty of activity. You will find it hard to get them started from scratch, i had to go catch a few soldier flies and place them into the system where they layed some eggs and it got going. Soldier flies wont lay their eggs where other maggots are already active so you need to get them going first, then they will keep the others away as they wont lay where there is an active soldier fly colony.
Def need to run the ramp up the side and if need be pipe it to the centre exit.
Cant see in your pic but need drainage or false floor in bottom as a liquid tea is created and requires removal. I made a cavity using wire mesh and shade cloth on the bottom, my scraps sit on top of the shade cloth, there is a tap in the bottom for draining the tea for the dirt garden. Need to keep in moist also or the lava with cocoon in your harvested instead of climbing the walls to get out, this is a problem i am battling at the moment.

I have a large batch of larvae coming Tues. or Wed. I bought a bin from Lowes and will be incorporating all the suggestions I have found here and other places. Thank you all for the help. I just hope I can get enough food scraps together! LOL

Ok, here is my new system. It took about 30 minutes to put together.


I used scrap pieces of 1" pvc pipe for make space on the bottom for drainage.



I lined the bottom with non-natural fiber furnace filter material. Added twin ramps from 1-1/4" pvc cut in half.


More pics to come. I hit the 3 pic limit.