I currently have a 120 Gallon Freshwater Aquarium that runs on two canister filters. I have never used a sump but would like to look into it. Problem is the tank isn't drilled so I would have to use a HOB
overflow box. My concern is that I've heard that if the siphon in the box ever gets broken (power outage or something) you can overflow your tank if the pump keeps running. Anyone have experience with external HOB
overflow boxes that can offer any advice? Obviously people must use external overflow boxes successfully?