no drilling

I am looking to convert an 120 gallon fresh water tank to a saltwater tank. I was looking for a HOB overflow as I want to avoid drilling into the tank. It is also a rimmed tank. Any recommendations?

Guys, I need an experts advice on the method I am planning to do on my future tank for overflow. I am a newbie and need guidance: I am planning to go with herbie method, I have a tank that I dont want to drill, I am planning to have a tube going from main tank (placed high) to the sump with...