Hey, ill start with my system. I have a 180 gallon Sw setup. I have a simple 2 light T5 fixture, 3 power heads, sump, glass top, PM protein skimmer bullet 3. My tank was at 86 degrees cycling. I would like to eventually get rays, a shark, eel, and maybe a puffer. Mt question how can i get my water temp down without a chiller. I tried no heater, no glass top, shutting 2 powerheads, and venting the cabin. My temp is now 80 but it still a little warm for sharks and rays.