First the good news:
rryyddeerr;160426 said:
... i cant imagine its cheap to keep a tank chilled in the summer.
If you do it carefully, it's not very expensive. By "do it carefully" I mean study how heat works (convection, conduction, radiation, insulation, etc) and do everything you can to keep heat out of your cold system:
1) Add the least amount of heat possible
. Use external (air cooled (Iwaki)) pumps instead of submersible pumps.
. Use a single pump instead of several
. use low powered lights that don't radiate a lot of heat and/or cover the tank with
. glass, which reflects radiant heat
. Don't let the warm lighting unit rest on the tank top, and conduct heat into the top.
2) keep the heat of the room out of your system:
. Insulate the bottom, back, and maybe one or two sides with styrofoam insulation (1"-2" thick)
. Add a 2nd pane of glass to the uninsulated sides of the tank, w/ 1/4" airspace in between.
. Keep plumbing short, and covered with pipe insulation.
Not to dash your dreams against the rocks or anything, but ...
rryyddeerr;160426 said:
...i plan to dig a trench leading away from the basement on the outside of the wall about 6-8' deep. through the wall will be an inlet and an outlet for 4"pvc. outside the wall, in the trench i plan to run a circuit of pvc, the ends of which will attach to the inlet/outlets in the wall. the idea will be to pump water out of the house, through the pvc, which will be buried and cool, and back into the house/aquarium system.
That won't work. After a day or two the warm water will simply warm up the dirt around the pipes. Even if there were snow on the ground, the dirt would just take a few more days to warm up. The dirt will act as an insulator. It would knock your temp down a couple of degrees, but that's about it. Once the heat goes into the dirt, most of it has no other place to go, except to slowly seep into the air. I know, the water coming out of your faucet gets cool if you let the faucet run for a while, because the pipes are buried in the cool ground. True, but that's because the water is holding still in the pipe 99% of the time. Your tank will supply a never ending moving stream of warm water, and the ground can't absorb a continuous flow of heat. The dirt will "fill up" with heat after a few days.