Question About Sump Overflow Box

[pbkuhn123]

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?

 

[coralbandit]

Go CPR overflow with a Toms aqualifter......
CPR CS102DX Overflow with Aqualifter Pump 1200 GPH Class "A" Seconds $Ave | eBay

If you are not afraid to drill look into the new Eshopps...
https://www.amazon.com/Eshopps-Ecli...d=1469056235&sr=8-9&keywords=eshopps+overflow

 

[pbkuhn123]

Thank you Coralbandit! I didn't know this Overflow box existed! Continuous siphon? I need to read more about this. Sounds like a good option and yes, I am afraid to drill and not even sure it's possible since this is an operating tank with happy inhabitants!