81 is not excessive, unless you have some non tropical animals that need
colder water.

http://www.rshimek.com/reef/Default.htm


JG wrote:

I have a new 125 gallon tank that I'm just getting set up and it's
running a little hotter than I'd like - 81F
I'd like the temp to be about 77F, so I only need to cool down 4
degrees.
I have a clip-on fan blowing on the sump, and two 3" Radio Shack fans
blowing on the lights.

I thought about buying a piece of titanium tubing (can buy a 3' length
for $40 or so) and bending it into a coil.
Then pump water through it and blow a fan across the coil.

Would this have any affect, or is the coil too small?

The other thing I haven't tried yet, is replacing the solid glass
cover on the top of the tank (that the lights sit on) with eggcrate.
The eggcrate will allow for more evaporation, but now the water is
more directly exposed to the heat from the lights so I don't know if
that will make it better or worse.

Jeff