[SZHTTM]

Here are some links that might get your thoughts rolling...
1) http://www-2.cs.cmu.edu/~cap/raid/chillers/diy/
2) http://www.wetwebmedia.com/chillersmar.htm
3) http://www.kingvinnie.com/aquaria/di...age.asp?cat=10
4) http://www.becnel.net/james/reef/cool.html
5) http://ozreef.org/diy/images/chiller_diagram.html
6) http://www.guarriello.net/chiller.htm


I myself have the 1/4hp Aqua Logic Cyclone with the drop-in portion to cool my 92-gallon.

Good Luck;