So my heater malfunctioned during the night and I wake up this morning to some bad smell and I realized that my 100g reef tank was all with like white/murky water, I touched the water and it was really really hot, my external thermometer was at 99f and because it can't go higher. "Everything" in the tanks died, about 15 fish (tangs, wrasses, blennys, etc), dozens of RBTAs, Zoas, Hammers, etc... only thing that survived were 2 big hermit crabs that were fast and clever enough to go above the water (they were hanging on tubes). Oh, is so painful... I have already done 45 gallons of water changes, removed everything I can see that is dead and water is better (now cooled) but is still murky. I think tomorrow I'll do another 45 gallons water change. I have had the heater for a year (same time I have had my tank) with no problems. It was a 300W Hygger brand that I bought because it had good reviews in Amazon. I just bought an external controller for my next heater. I'll start to do more research on external controllers and equipment to prevent accidents. My wife has even told me to dry the tank and forget about the hobby for a year or so, and I have think about it but at the end is my hobby, so I'll try to recover and add simple things in terms of corals and fish. Luckily the next coral market is soon so I'll start to replenish there. I leave a pic of my tank before Xmas. I'm looking at my tank now and I still can't believe it... be careful with your heaters.