Installing sump without drilling the DT

[mrhasan]

A friend of mine recently started a 29gallon nano and he is thinking of adding a custom made 13 gallon sump refugium.

Now everyone install sump with drilling but I was thinking whether it is possible to do it without drilling the DT. The idea I am having is putting a power head in the tank to draw out water from DT to sump, and then having a return pump of same gph to return the water to the DT. No overflow box and no drilling :P

Since I don't have any knowledge on sumps I am not sure whether the idea will work. Suggestions please