Backyard Aquaponics
A place to discuss aquaponics

I started this topic for two reasons:

1) Keep a public record of my ongoing experiment

2) Hopefully pool information anyone can use

I have a large compost pile that heats my greenhouse. (See my system in Member's Systems) and I plan on using the fuel generated eventually for much more. (Including BSF larva for fish feed.)

My compost pile is about 140 degrees F at the center and is a great source of heat. My inspiration is Jean Pain and I plan on building on his work. What have you been able to use compost for?

I do compost but not in my greenhouse. I make to much compost to fit in my 12x32 space with the two growbeds and three fish tanks and two sumps. My dairy goats spill lots of hay, the rabbit and chicken bedding, pig poop, it all amounts to at least one 30 gal GI can a week if not two. Then there is the glycerol and wash water from making biodiesel and the crunchies in the bottom of collection drums. Add to that the product of our dry toilet and the urine drains from it and I keep three or four piles of three cubic yards each. Between the urine and alfalfa there is plenty of nitrogen. When I harvest an animal the innards go in the pile.
First we age it a full year before use because of the humanure in it. We use it to mix with soil to top off the raised bed gardens. We use it as mulch to keep the ground more moist under trees and plants. We also depend on it as fertilaizer, using no chemical fertilizer. After sifting I use it as bedding in my worm farm or to grow flats of wheat grass for juicing or as potting soil.
My new piles run up to 150 deg. F But once a bin is full and no more stuff is added it drops to about 120 and finally after eight months or so it falls to about 100 deg. Because it is very dry here I keep the piles covered and do not turn them. I will uncover an aging pile once a week and drive a steel rod into it in numerous places and streatch the resulting hole by pushing the rod back and forth. That allows air and water access to the interior of the pile. Then I water it and loosely cover it back up.
As useful as the compost is the means of disposing all this stuff is very convienient. The land fill will not accept liquids
and it is located 30 miles distant

I read the humanure handbook several years ago. We were still living in an apartment then and only had a 9 foot by 9 foot patio as outdoor space to work with. (making very hot, non stinky compost in bins or cans is really far more difficult than the more old fashion way with a pile on the ground with 3 sides bin. But we managed to do it and as far as I know, no one complained.)

As far as uses for compost. I don't think I need to come up with more uses for it because it seems that no matter how much I make, I still need more!!!!! We use it in the gardens an around all the plants. The Humanure compost takes a long time since it should be allowed to age for a year with no new additions before use.

Our compost gets up into the 140-160 F range in the hot top center regularly but in our climate, it doesn't make much sense to take up greenhouse space with compost bins. In a cold climate I can see it being helpful though.

My favorite thing about composting is after starting composting, suddenly the trash bin rarely fills up (if you avoid putting stinky stuff in the garbage can, you don't have to take it out to the curb till it's full and you don't have the nasty stink problem.) Under normal circumstances, we might only put out trash for collection about once every three weeks and it is often still a half empty can.

Of course all this composting activity has made us the compost whackos of the neighborhood who drive around and collect the yard waste (lawn clippings and bags of leaves) that everyone else rakes up and puts out and we rush home and dump them all over our own yard. (Not all composting has to be done in a bin, in my climate, anything dumped on the ground and kept moist will rot very nicely to improve the soil. Sheet composting or lasagna gardening are common terms for this.)

I think one member here on the forum did run some trials of composting to heat his water. He found that it was a heck of a lot of compost and work turning it and all to keep it hot enough to have any effect on the water temp of the tubing buried in the piles. I can see where a more passive composting action in a greenhouse could have a beneficial effect on the air temperature in the greenhouse but I think it's been proven that you are not going to harvest huge amounts of btu's from compost without putting huge amounts of effort in. As in, you are not going to heat a house using some tubing buried in a cubic meter of compost sitting in the back yard. If you are in a climate that needs much heat, the compost will need that heat for itself for the winter and there wouldn't be enough to go around for long. Inside a greenhouse, the compost might share some heat and the greenhouse is sharing it's insulation so it is more of a benefit both ways if you have the space inside a greenhouse for that much compost.

I have a pretty big compost pile and the 500 feet of water line coiled though the compost pile provides a lot of heat for the greenhouse. Also, it is better if you do not turn the compost, both the humanure handbook and Jean Pain bring that out. And I live in town so I don't have a huge amount of space to work with. But careful planning can enable you to get the most out of the space you have. Anyway I'll everyone posted with my results.

If I had a greenhouse I'd have a pit under the benches for compost. Load it up and let the heat warm the plants above it. When the compost is ready it would be very close to use. More projects, just not enough time.

No worries there, I don't turn compost, We humanure compost and turning is too much work anyway.

Right on TC, we use humanure as well. Although our family thinks we are bonkers.

With the spent hops we put in and humanure we got a bumper crop of BSF larvae. How does yours do in Florida? Any critters help with compost?

We never seem to have enough to feed the compost pile so we use stuff from work and neighbors. We even have a route with coffee stands.

Well we are not trying to heat a greenhouse with compost so we are not nearly as involved with it. BSF larva seem to like our worm bins well enough. We could have some in the compost piles too but I don't usually go looking for them in there so don't know. There are always small critters in/around compost and worm bins down here (bugs and such and lizards to eat the bugs.) I have had some issues in winter with rats trying to nest in the aging compost so our new bins will have hardware cloth sides to make it more difficult for them to get in.