Recent knee surgery has had me staring at this thing for the past couple weeks:

DonJoy Iceman Continuous Cold Therapy Unit

and it's gotten me thinking...

Has anyone ever made a short term chiller like this? It's really just an Igloo cooler with a fish pump in it. If you use cooler packs instead of ice, I bet you could drop a tank's temp by ten degrees in a hurry. If anything it might drop the temp too quickly. Ice pack "management" could solve that though.

I coulda used one last year - struggling to keep temps down right now as well.