I have seen this very idea used to cool an inground pool. The owner liked to be refreshed when swiming he kept his pool temps rite around 70. But he only had partial flow going to the underground pipe. Its funny the same thing cgcarver is dreaming about me and my dad have been contomplating but for him to do it would be much easier than cg as my dads house was built in the early 1800s and is gravity spring fed for water. The temp is aconstant 54 deg. at least i think that was the temp its rite around there and the flow into his basement is about 5 gal
a min but we wanted to do brook trout as they are redily avail in the stream that runs past his house. But if we do it I would like to go acrilic (a little more forgiving in lower temps) and go atleast an 8' tank but the price is the barrier if I come up with an extra $2000 somewere it will happen.