My tank rarely gets below 82 without a heater. One thing about this time of year is that humidity is high in our houses, because we don't have the AC running all the time. This makes a huge difference in my tank. Last wet spell we had my tank temp shot up to 86. First step was to get a clip on fan pointing at the sump and run my refugium light only at night, but I'm worried about the summer. I may have to switch skimmer pumps (T3, adds a couple of degrees), ditch my canopy, and go for open top w/HQI mini pendents. I've got the icecap fans in my canopy, but I still think having an open top would cool things down quite a bit.