I'm not sure I understand the part with the rods going through, but here's some thoughts.

Coffee, as it composts, goes through a hot phase that can kill the worms. I'm not sure if rabbit poop does too or not. It would be good to pre-compost the coffee before it goes in with the worms. I'd think that one of your big drums, coffee, water, seal the bin with some holes in the top, put it on it's side and roll it every day or two to mix in oxygen in. (Unless you already have a standard compost pile - just use that.)

Yes, you want to divert the urine. The ammonia irritates the worms skin.

Think about turning your drums in to flow through bins instead of cutting them in half. FTs generally process faster because of the increased oxygen flow. At 22 inches, the bottoms of your half bins won't get much in the way of air and the stuff down there will probably either not compost at all or it will turn anaerobic. It will be a little more work, but if you can put a large thick tarp under the rabbit hutch and shovel the poop into the FT bins, you'll have more success. Closed bins (with no holes in the bottom) need to be pretty shallow. FTs take up a lot less surface area for the amount of 'food' they process. I think you were going for the vertically cut bins to cover the bottom of the hutch without gaps. Maybe you can still do that but pull one or two of them out every couple of days and empty them into the FTs? It depends on how many 55-gal drums you have.

Check out the link below about how others have made FT bins from scratch. Skip the top small ones and go down to the list to the bigger ones. I know people successfully use worms to compost rabbit poop.

I didn't notice you say anything about bedding. You want to add about as much bedding as you do food. You need the right ratio between carbon and nitrogen. Coffee grounds and poop are high in nitrogen, so you want something like leaves, dried grass clippings (green, they also go through a very hot hot phase at first), newspaper, cardboard.....) I have rats and the poop and wood shavings make a good mix.

Here is a link that might be useful: DIY Flow through bin list

Thanks to susanfromhawaii who said:

> I'm not sure I understand the part
> with the rods going through, ...

The rods would be supports for the bedding (newspaper, etc.) and would pass horizontally from one side of the half barrel to the other, 4 or 5 inches from the bottom of the bin (which used to be the side of the barrel). I will have cut them so they would be lying on what had been their sides, with the old top and old bottom now being the ends of the bins. The rods would be parallel to the cut edges.

> Coffee, as it composts, goes through a
> hot phase that can kill the worms. I'm
> not sure if rabbit poop does too or not.
> It would be good to pre-compost the coffee
> before it goes in with the worms.

Would using black soldier flies do the same thing? I read here, some weeks ago, that BSFs "precompost" the garbage, and that worms love their waste.

> I'd think that one of your big
> drums, coffee, water, seal the bin
> with some holes in the top, put it
> on it's side and roll it every day
> or two to mix in oxygen in.

I haven't had much success with an "Urban Compost Tumbler" that does just about what you're suggesting here. But it's sure worth a try.

One of the goals of this system would be to reduce the amount of work we have to do to keep the rabbits from offending the neighbors. With something on the order of six does and a buck, we could have several dozen rabbits at a time. My back isn't what it was, or maybe it never was anyway--so I am not looking forward to moving large piles of manure every week (or even more frequently). But, as I've noticed, there are some sacrifices we must make to get where we need to be.

All the best,
Le Sellers

The rod system makes a lot of sense now. It will make sure that the depth of the compost isn't too deep. That takes care of my biggest concern.

I have no idea about BSFL, so we'll see what others say. I'm in a studio apt, so I have no experience with the tumblers. They just sounded like less work than turning a compost pile with a pitch fork. You mention in your first post having a ton of 'them' in a pile in the yard. If you mean coffee grounds, you may already have taken it through the hot phase.

You may still want 1 or 2 of your barrels as FTs. With the vertically cut bins under the rabbits constantly getting new 'food', the VC will never be finished. You might empty one or two of the bins under the hutch into the FT every few months so that the VC eventually gets finished. With the FT, you don't have to wait until one batch of VC is completely finished before adding more on top. Also, you won't have to buy new worms for the FTs. By the time you need them (quite a few months in to the project), your worms will have multiplied and you'll have enough for both types of systems.

Since I assume this will be outside on the ground, I recommend a few holes on what were the sides and will now be the bottom of the barrels. Below the level of the rods. This will solve 2 problems. 1. If you let any leachate stand for a long time, it will get anaerobic and make your job later MUCH worse. 2. It will allow some oxygen in the bottom of the system which is a good thing. Best of luck with your project!

Thanks, Susan.

It looks like moving the rabbit droppings from under the hutches into flow-through worm beds may be the easiest system. You're absolutely right that the rabbits would make an endless supply of "food" (hard to think of rabbit dung as "food" but worms like it, apparently). I'd really like to design a system that was truly "flow through", so I'd only have to harvest the compost every few weeks, but that doesn't seem very likely.

All the best,
Le Sellers

Le; Please keep us updated on your system. I picked up 4 rabbits last week and know rabbit pellets are a great source of worm food. I will be in need of a system and like you would like a proven one, I will not have the coffee grounds just rabbit pellets and spilled rabbit food/hay.

Curt

You could build a big FT the size of the bottom of your hutch or perhaps you could build a somewhat smaller FT and some sort of square funnel (I'm thinking stainless steel sheeting) to help you have a smaller diameter FT. How are you going to keep the urine out?? You may be able to do something with that to funnel the poop in to a FT. If you go the FT route, BE SURE to put sturdy wheels on the bottom or you'll be on your hands and knees under the hutch to harvest the thing. That way you could have all your worms in one big bin. The stilts on your hutch would have to be pretty high though.

I'm thinking as I go along, how about a slanted stainless steel sheet under the entire hutch with a vertical end, say 4". Then you sweep all the poop that rolled down off one end in to the FT? If there are drain holes at the bottom where the V is, most of the urine will drip out and leave the poop.

Here's a try at a cross section because I know my description isn't very good.

\
\
\
\ ]
\]

Hey!, my diagonal line didn't come out. They deleted the extra spaces. You'll have to connect all the \ signs to they connect and form a diagonal line.
The far left is one end of the hutch and the far right sticks out past the other end. Holes to drain urine at the bottom of the \]. I'm not sure, perhaps others with rabbits can chime it, but you may need to briefly rinse the poop to get most of the ammonia out just before you drag it to the end to dump in to your FT. This should save wear and tear on your back and knees and still solve the problem. Poop may stick to the steel sheet, but well aimed high pressure water should solve that. FTs can take a lot of water and you'll just get a lot of dripping at the bottom of the collection part of the FT. (The drips coming out of the bottom are called leachate.)

You may want to start a new thread about rabbit urine and worms if no one responds to this one. I know there are other rabbit/wormers out there. I'm a rat/wormer and store my poop/bedding for long enough to dry out really really well. Two rats produce a lot less poop than 6 rabbits!

If it were me, i would not waste the effort on diverting the urine. I mean just how are you going to do that easily? Plus the urine is a great source of nitrogen.

I would add a little labor and simply add the rabbit waste plus coffee grounds plus paper/junkmail etc to a compost bin. Then, after allowing it to partially break down, feed some of the stuff from compost bin to the worms.

I use a similar method for my worms although I don't have the rabbit manure.

The issue is a bit more complex than I have described it because I left out the bigger picture.

The rabbits will be below several levels of grow beds in an aquaponics system. It looks like this:

Here's the top of the Greenhouse> ^

[This is a grow bed]

[This is a grow bed]

[This is a grow bed]

[This is a rabbit hutch]
\. . . . . . . . . . /
.\ . . . . . . . . ./ These are deflectors for the droppings
. . . . . . . . . ./
. . . . . . . . ./ (Imagine that the two deflectors "underlap" so the longer side is below and to the left of the end of the shorter side.)
. . . . . . . /u (This is a PVC pipe under a few slots in the deflector.)
. . . . . . ./
[This is the worm bin (or dropping catchment)]

. > (Here are the fish) > \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ This is the floor of the greenhouse basement. The deflectors are corrugated fiberglass with the corrugations running top\-to\-bottom. As in the diagram, there are slots in the longer one (across the corrugations) with a tube below it (a half 1ý" PVC pipe) as a gutter. They'll connect and dump the urine into the fish tank (immediately adjacent to the pumps that run the nutrient\-rich water up to the grow beds), or we may have to treat it before running it into the plants. Here's the reason I have only ~18 inches of vertical space for the worm bins: the "basement" in the greenhouse is already six feet deep, and each of the components has a minimum needed space to fill its function. All the best, Le Sellers

I have read that urine is very good to help jumpstart composting. Sounds like you have a good plan, good luck

Your 4th post leaves me much more happier. I am glad you are capturing the nutrients in the rabbit liquid waste. At first I feared that was all lost. And considered waste. Shocking. I can understand the difficulties with the height requirements especially since I would like to squeeze in a layer of chickens below the rabbits. Any ideas on how to keep the chickens dry and make excellent use of rabbit liquid waste would be great. Probably not much of a market for yellow rabbit fur.

Yellow chicken feathers or rabbit fur doesn't seem too marketable to me, either, but keeping them dry might be as "simple" as running the deflectors completely from the front to the back (or back-to-front) below the rabbits, then do the double-deflection and diversion below the chickens. This uses the rabbit urine as a flushing medium (chicken manure is too dry to flow, but not dry enough to roll). You might have to add more water to flush effectively.

(By the way, I chose "double deflection" so there's an open space for me to add the coffee grounds and other kitchen waste into the worm bins. Single deflection would make the angle on the deflectors too shallow for the droppings to roll into the worm bins--rabbit "pellets" are dry, but they're still sticky enough that I worry about their not making the full trip on their own. It would also put the urine gutters too low on the deflector system so they'd be in the way. There are a few other, minor, advantages, too.)

As you know, chicken manure is very "hot", so I do not know if worms could manage it for you, but letting it compost ahead of time would probably work. Black soldier flies might be helpful here, too, but I am no expert on these insects. Others might answer this for you/us.

All the best,
Le Sellers

Wow! You're light years ahead of what I'm suggesting. I'm very impressed with your system. It sounds like you've thought everything out completely. Let us know how it goes!!

I skimmed....

I have a friend who -on a much smaller scale- has rabbits and coffee grounds and worms... I recommended she sprinkle in some sawdust for browns and the mix...

Just an idea, albeit from a newbie....

Mike

I've been out of town for a while, so I haven't been able to follow the discussion here.

Thanks for the encouragement and ideas. We're starting with some red wrigglers that should be arriving next week, and a "Worm Factory" my Jacquie asked for for her birthday. (Not exactly diamond earrings, but hey, she wants it, she gets it.)

We've just got our preliminary aquaponics system up and running this past couple of weeks and while we were gone, the only thing we had to do was have a son stop by on his way to work every morning and feed the fish.

The "sacrificial" gold fish in the tanks were pooping, the bacteria were converting ammonia into nitrites and nitrates, and the plant grew unbelievably well: tomatoes went from three inches tall to over seven in six days under plain ol' florescent light (and some sun through the window); stevia from under one inch to nearly three; lettuce nearly ready to harvest; spinach getting major leaves from just a few green shoots. We're happy with it. It cost $500, and we already have something approaching $100 worth of food growing and that's without food fish in the tanks. (That's for early April: tilapia.)

No worms or Black Soldier Flies yet, but it's only a trial/experiment and we're learning a lot. (My own design: we have five grow beds and two fish tanks.) Learning a lot and getting lettuce, basil, tomatoes, peppers and stevia up and growing. Jacquie figures that we'll be able to feed ourselves all the greens and half the tomatoes we eat beginning three to six weeks from now (two months to four total). And we're still expecting two major frosts/freezes before real Spring gets here, so our standard garden will not be producing anything at all while we'll be eating home-grown veggies and fruit.

The greenhouse is sitting in the back yard: we put it up last year, before winter set in. The "basement" is waiting for us to do the concrete and block work. (We have to have warm temps for a while so the underground utilities can go in, and so the concrete and mortar can set well.)

As things progress, I'll be sure to let you all know what's happening. If they go as hoped and planned, we will be able to feed ourselves and many of our 27 grandchildren rabbits, fish, veggies, and fruit from our two aquaponics systems and backyard. No grain, takes too much space, but coupled with the literal kitchen garden (sprouts), we could eat healthy for years without ever going to the store for anything (and there are people out there who believe that there won't be anything in the stores anyway--no trucks and nothing for them to haul).

All the best,
Le Sellers

I'd love to hear an update, Le Sellers. Did you get your tilapia yet? I realize I'm probably to late to chime in about design, but I'm wondering why you want a worm bin in the system at all. I am building an AP setup similar to yours, with rabbits, tilapia, red claw crawdads, worms, and BSFL. I have my rabbits on the north side of the greenhouse, as they don't like the heat. Their cages are stacked 3 high, with a 'roof' under each one that slopes to the rear, where they drain into plastic gutters. The gutters have a constant flow of water that loops to the tilapia tank. The poo rolls down the roof, and takes the log-ride to the fish tank, where theoretically the tilapia will munch away. The urine is quickly diluted, and pumped through the GB's. The BSFL bin will be in the greenhouse and will take all organic wasted that rabbits don't eat (meat table scraps, fish guts, rabbit guts) and the BSFL harvest tube will drop directly into the fish tank. The worms are located in the GB's. Your coffee grounds could be added to the BSFL or the GB's where the worms will find them. If all works as planned, then all I have to do is feed the rabbits, and tend the garden, no poo shoveling or sifting through castings or turning of compost piles.
I've got a few tilapia, some breeding red claws, and 5 pregnant does, just need to hook it all up. Any suggestions?

lesellers: Did you end up diverting the urine or making use of it someway?

pjames: "urine is a great source of nitrogen" Agreed. A large source of leaves or cardboard or something will be needed to balance the urine and coffee grounds.

A key might be low or not maximum densities of rabbits. A balance against less work.

J Pizzle: Your setup sounds very cool also. It will be interesting to see if once many rabbits are plugged in if the urine can be handled in the system. It is asking a lot of the system. I am wondering how slack or excess capability or back up emergency can be put in place. If water quality temporarily goes to low for the fish you could always do a partial water change and pipe the nutrient over rich water into your garden or compost heap. I am also curious if when gutting the fish you find any BSFL that have gone most the way through the fish without being digested. They like to eat them but I am unsure if they get digested.

Side note: The crawdads are just the coolest thing in the system. They do a good job and are ideal to round out the system with more diversity and food products. My "system in the future" of my dreams has them. To get into the spirit, I eagerly ordered some in a restaurant. $$$. Although I can eat lobster, steamer clams, muscles, and even had some escargo I just could not touch the crawdads. I was afraid of them. It is a great food for the future of aquaponics. I wish I had grown up eating them or that I can fix this problem in me. They look delicious. Maybe crawdad salad done like lobster salad will do the trick.

For those interested in adding fish or crawfish, or plants to their red worm system there is Aquaponics Digest. It is or used to be, none recently, e-mailed daily or whenever there are posts. It is very informative and a leader in this type of information. It is also very difficut to read because the posts are raw with no formatting. So a reply has the original post and the reply. A reply to that has the reply, the second reply, then original post. And it only gets worse from there. How to sign up for it, or cancel it once on the mailing list is also a bit of a mystery. But the information and experts are there.

Also a company I will not name makes rabbit and chicken houses in rounded plastic shapes. They specialize in easy to clean, easy to feed, easy to harvest eggs, good protection from the weather animal houses. Sort of like little tikes brand playhouses but for rabbits or chickens. They also make behives. It would be great if they made a rabbit, chicken, vermicompost house. A couple rabbits, a couple chickens, and worms. It would be great if I could purchase these individually and stick them together ala Lego. Rabbits above Chicken above Vermi. It would be great if I could stick these units together for larger units, side by side. I also want an add on so I can walk into a dry, not freezing area next to the animals to care for them, water, feed, observe, harvest eggs. Greenhouse plants or hay storage above the rabbits and aquaponics somewhere in the system would be just asking for too much. The advantage of this would be no seams to make cleaning difficult.

Vermicompost part of a larger system.

Equinox: I see your concern for backup planning. I have given it some thought, and will think some more I'm sure before I push the limits for stocking densities. In my scheme of things here, in the event of power failure; the rabbits will be fine, of course. Their waste removal will back up in the gutters because there will be no water flow to carry it to the fish tank, and that is a good thing. The growbeds are bottom draining, so stagnant water will not be a problem. The plants and worms will do just fine with hand watering once every couple of days. The fish and red claws are most at risk, but a battery backup bilge pump will keep at least a minimal circulation of water. It is important not to feed the tanks during the outage time as well, so as to minimize ammonia buildup. Actually several things should naturally occur to keep catastrophe at bay for a while. Absence of circulation pump will keep rabbit poo in gutters, and out of pool water. Toasty 82 deg water will cool, which will lower the metabolism of fish, and increase dissolved oxygen potential, and the greenhouse should keep it all from cooling to low or too quick. I'm sure that day will come, so I'll let you know if it all goes as planned then.
Interesting question about the digestion of BSFL. I don't know. I haven't fileted a tilapia yet, and won't for some time. Maybe another reader knows. I would assume so, have you seen a whole BSFL come out the other end? Even if so, the red claws will finish the job I suppose. Speaking of red claw, I ordered 18 'small breeders' from Stick Fin two weeks ago. They arrived last Wednesday, and this morning I noticed a female already holding a load of eggs. I highly recommend Stick Fin

The power outage automatically solves many of its own issues. I feel way more confident with your excellent explination of things.

Online I have read only one place that reported mature BSFL non digestion. Moist sides of the bin will allow the "tenderer?" white non mature BSFL to also migrate. They also reported the fish prefered the non mature BSFL. ... But they did not have creative crawdads to amuse. :-)

As with any manure, I would compost it first until the exothermic phase is over with then i would add the worms to that compost pile or tumbler which will speed up the composting from years to months. If you use black and white newspaper (tons thrown out by libraries every month or cardboard to line the rabbit cage you can just wade that up and throw into the compost pile. Good to have more than one compost pile or tumbler.

It's actually the male crawdads that carry the eggs around, not the females. I would love to see photos of these setups, they sound very very interesting.

How would you divert the urine, while allowing other waste to fall into the worm bin?