Chiller Q.

[TheReefGeek]

Have you tried other methods of cooling your tank? I have had a 100g tank with metal halide lighting, and no sump, in a second story apartment without air conditioning and never had heat problems in Edmonton.

Before investing in a chiller, you should install some fans across the surface of your sump to increase evaporation.

Also try to keep the heat from your lights out of your tank with fans as well.

What kind of hood are you using? Is your tank open top? If not open top should solve the heat issue. If you can't do open top, install some fans in your hood.