Summer is coming, and we all know high temperatures and reef tanks don’t mix. What few don’t know is what we should do about it, so I’d like to share my experiences over the last few days. At the retail store I manage, the AC unit has been down for most the week, and with temps in the high 80’s, it’s been a lot of work keeping things under control. We weren’t prepared for this situation, but with some quick thinking, a lot of sweat, and some unconventional ideas, we managed to survive. The first thing we jumped to was probably the same thing most would. Ice and lots of it! We froze just about everything we could pack into our freezer from water bottles and bags of water to little cups of what we have come to call “RO cubes.” This works great to a point, but it takes a lot longer, even in a sub zero freezer, to freeze water than it takes to thaw it in tanks. This took me back to the drawing board, but luckily I found that our water storage tanks stay relatively cool, and a 10% water change drops any system about 2 degrees. This worked great for our quarantine tanks, but what about the 300+ gallon coral and fish systems on the sales floor? 10% water changes take far too long, and the temperature jumps up too fast for this to keep them stable–and this is when it hit me. On every floor system we have an emergency overflow on the sump that drains to a sink, and lines for salt and RO plumbed to each system. I decided to open up all of them a little and just let the sumps overflow out the drain perpetually. This stabilized systems that were getting close to 86 degrees right at about 81 degrees. Now we’re talking! Now for the source of my real concerns, the 75 gallon SPS display that’s been my pride and joy for the past year. It sits right in front of the windows, and with tons of equipment running, can build up some major heat. For this one I decided to snag the fan off one of our Cadlights display tanks, and to my surprise, it worked great. Not only did this little fan unit keep temps in the safe zone, but it made the heater have to click on to keep temps up! Wall system right next to the SPS display 86 degrees, SPS display 76 degrees, Cadlights fan PRICELESS!!! All smaller tanks seemed to react well to ice, but with such small water volume, that’s what I expected. So what did I learn from this? I learned that having a couple of water bottle in the freezer is no remedy in the case of long term heat spells. I learned that, if you have the water and the motivation, you can keep temps down by adding cool water. Most of all though, I learned that the power of evaporative cooling is huge. FANS,FANS, FANS… Needless to say, I’ll have a lot more fans on hand from now on!