You're very welcome.
Your project sounds like a feature for the Biotope.
RE: your geodesic dome--water would probably condense on it, giving rise to mold, which would cut back on light and so it would probably require frequent cleaning. You'd need to design it so you could be sure to reach all the surfaces.
With free-standing tubs, I've had the best luck with sailfin mollies. I filled the tubs with sea water made from instant ocean, and let them graze on the marine algae. I have a theory that sailfins grow bigger on marine algae than on freshwater algae. Since they're intertidal creatures, sailfins can well withstand extremes in temperature, whereas something that likes it a little cool, like goodeids, would probably boil and die.
Other candidates for yard tubs that I can think of offhand would be desert pupfish, and our Chesapeake Bay version, the Sheepshead topminnow. But, at the end of the summer, you'd have the same problem that I imagine Donna had with her paradise fish--a surplus of nasty little buggers to bring in in the fall.
One other point about ponds--most people think that the fish will thrive and do well on mosquito larvae. I don't think this is true. I've read of studies showing that mosquitos avoid ponds with fish in them. The theory is that after the larvae pass through the digestive system of a fish, chemicals are released from the fish waste that warn female mosquitos away. So you might need to feed your pond fish.
This is the same principle as "schreckstoff"--German for "fright stuff," I think. Studies have shown that native minnows will avoid an area where northern pike have been feeding on minnows. Again, chemicals are release from the pike's waste that the minnows learn to steer clear of.
http://en.wikipedia.org/wiki/Schreckstoff
<div class='quotetop'>QUOTE (animicrazy @ Apr 28 2008, 01:32 PM)
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Thanks DC & Sonny Disposition !!
I was fantasizing (partially) (as in I have to dig the back yard up anyway; sooooo....) along two avenues. There are a bunch of big deep water fish in the rift lakes that I would think could, as in they are used to it, take colder temps - and thrive. Also, screen enclosures are pretty cheap and many have provisions for plastic walls - of course my ideal setup would be a deep water pond surrounded by an organic garden and covered by a geodesic dome; and a thick piece of acrylic over the pond with a round patio type table and chairs (now that's dreaming). As for heat, I've been reading a lot about materials that absorb and store solar heat, or waste heat from a generator, composter etc., and release it to where you need it - such as the pond in the winter.
The point of not seeing skinny fish is a good one, but if they get big enough - as they should - that might not be so bad. Also, the fact that many threatened species are threatened because they get big and then eaten by people adds a satisfying (to me & hopefully All fish keepers) aspect to the equation.
The next step would be to assemble a list of desirable fish and figure out what could live with what, not hybridize, and use all levels of the pond - kind of like a mini rift lake. Could even design a perimeter "river" with high flow rates for those type of fish. Temperature could really range from 50 - 60 at the bottom to mid to upper 70's at the top.
I could see fish from Malawi, Tanganyika, other African lakes and rivers, Central America, lower South America, and maybe other places. Maybe mix it up or not - depends on the hybrid factor.
So: Anyone ready to lend some brain power to the project? Digging the yard will commence in June - after graduation - once I start the dirt will be flying!
Paul.[/b]
