If you want to add a sump to your aquarium, then you will need to drill your tank and install an overflow box. The Shadow Overflow from Reef Synergy is by far one of the most advanced overflows on the market with its super thin profile, protruding out into the tank just over 1" which is almost unheard of for an overflow box. The water then passes through the wall of your tank into the secondary box of the Shadow Overflow where water can then drain down into your sump. The Shadow can be plumbing with a couple of different methods like the Herbie and Durso method, but we do suggest using the Bean Animal method since the overflow comes with three drains.
Installing the Shadow Overflow can be daunting, but if you follow the directions and take your time, it is a straightforward process. The overflow box comes with a drilling template that makes lining everything up very easy, and all you need to supply is a drill, drill bit, and some water if you are drilling a glass tank. Reef Synergy’s overflow can be installed on glass or acrylic tanks, with a 63mm-65mm drill bit. Reef Synergy does suggest a 63mm, but we have found a 65mm works just fine too and can be a little easier to find.