I think the mini fridge idea would work the more length of hose you can have in it the more effective it would be. You could just put the holes in the door to make it easy and a smaller inside diamater like 1/2 inch would work better than 3/4. Just my thoughts. I have been contemplating this for my 28 gal nano HQI gets pretty hot during the day when the halide is on. I still have my old mini fridge from college i also have a small freezer too. We will see as the summer progresses
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28 gallon JBJ Nano Cube HQI, 16 pounds of DIY live Rock, 10 pounds of Sealife live rock. 20 pounds of Black live sand. 1 ocellaris clown, 1 starry blennie, 1 orangespotted watchman goby, 6 sheepshead minnows, 1 pistol shrimp, 1 skunk cleaner shrimp, 1 red mithrax crab, 1 turbo snail, Various hermits and snails. torch coral, trumpet coral, various zoanthids, 3 ricordea | 
