I have a all glass aquarium with a tidepool sos overflow box that keeps breaking siphon. so I took one step forward and put a float switch on my main tank to avoid overflowing. one step ahead of the game i thought, well i was wrong I work third shift and just got home to find my main pump shut off (like it was supposed to), but last night got exceptionaly cold in my house and my heaters are in my sump. when i got home I found my Koran angel,yellow tang,coral beauty and cleaner shrimp, dead with the exception of my shrimp all of these I have had for over a year or two and grew quite attached to them. All my corals are sucked in very tight so theres no telling what will make it. The good news is my clown and peppermint shrimp look healthy still. I just had to tell someone thanks for reading.