I dont get what your talking about,and yes im worried about the sump over flowing when the power goes out,can you explain yourself more? BTW the over flow cannot syphon,cause the wholes are drilled on the bottom of the tank for the return and over flow,so gravity just pulls the water down to the sump,id have to have a air tight sump cause when the power goes out the water would just over flow into the sump and the sump would over flow,unless,im could make a DIY rock pillar for the tank and make a 1/2inch whole going to threw the DIY rock pillar and have the over flow go in the rock and to the top of the tank,then the water would only over flow a bit into the sump,and i would not have to have the sump air tight. Cheak out this tank,this is how id like my DIY rock pillar to look like,
