permaculture

[Mikal Jakubal <mjakubal@asis.com>]

Hi permie list,
Maybe y'all can help me with a design problem. I'm working out the design
of a small complex of structures: small chicken coop and fenced yard;
garden tool shed; small, fenced-in goose and duck pond; and maybe
greenhouse; and maybe greywater system. 

The fenced pond and yard are for the birds at night, or when I'm gone and
others have to care for them, or any other time that I don't want them
running around loose. All these structures are on a slight slope below the
house and on the edge of the garden in an area at the edge of a big tree to
poleward. I have a natural gas well on the property, so I plan to have a
hot tub since I can heat it for free. From this there will be regular large
dumps of water (warm if I drain it before it cools) from cleaning. (Hot tub
is above area in question.) The idea behind the goose and duck pond is that
it will be small--8' x 8' or so--and will have a bottom drain so that every
couple weeks it can be drained as fertilizer to the garden and orchard. I
decided I didn't want the birds in the fish and swimming pond--they'd make
too much of a mess of it.

Several possibilities came to me. One is that I could fill the duck pond
with house greywater, once it had been filtered a bit (I was going to just
refill the pond with clean water from the tanks above). And since most of
the greywater will be warm, it seemed a shame to waste the heat. The
original greywater plan was to just dump it into a mulch trench in a swale.
Okay, but I think I could do better. So, I've been thinking about attaching
a small greenhouse to the sunny side of the coop or the tool shed ( which
will be 10' x 10' or so), and installing some sort of aquaculture inside
that will make use of the heat and nutrients in the water. The cleaned
water can then overflow into the duck pond and be reused from there. That
would give four uses to the same water. (I can't water directly with
greywater because at some point the Health Prevention Department is likely
to get on my case. When this happens, I want to have a system that is
unassailable from a health standpoint because I refuse to get a septic
system and pay bazillions of $ for permits that I don't need.) 

So, my main question now is what sort of aquaculture can be done on a small
scale with resources I've described? Whatever it is, it has to be able to
stand at least mild soaps (I plan to use Oasis biocompatible soaps. These
are okay for plants, but what about other things?) How about a cement fish
tank with enough scum-sucking fish to directly eat the chunks in the
greywater so it doesn't have to be mechanically filtered? Snails?
Freshwater mussels? Where do you get species and info on culture? What
sorts of plants would do well in this situation (for human or animal food
or compost)? Being a warm greenhouse with warm water in it, maybe I could
grow Tilapia--but where do you get 'em around here?

I love eating fish, but when I raise them myself, I get too attached to
kill them. That's why something like mussels or crayfish are more
appealing. Or something I could sell, like water lilies or coi. Or maybe
some sort of prolific organism that could be fed to the fish in the big pond.

It has also occurred to me to make the duck pond a little bigger, add fish,
and fill it with water that has been filtered through a reed bed or some
such. Then, every time the hot tub is drained (hundreds of gallons), open
the bottom drain to the orchard while refilling the pond from the top. This
doesn't make use of the heat, but is much simpler.

Ideas?

Thanks,
Mikal