O.K. so I've had my reef set up for a little over two months now and have done several power outages to make sure I wouldn't have a flood, well today I got to do a partial water change because I had turned the power off to add some of the ARC Pink Fusion and then went to the grocery store well about the time I got there my wife called and said we had a leak in the basement I ask if the sump had overflowed and low and behold it had so here's what happened my vacuum break on my return is 1/16 which got plugged with salt which allowed the tank to drain down to the outlet due to siphon so now my vacuum break is 1/8 so hopefully that's big enough. So to all of you brand new folks like me, make sure your vacuum break on your return is big enough or get a check valve