CPR Overflow - Drill-free suggestions for my 44g cube?

[Chaloupa]

I had the Lifereef style with the U-tube on it....was quite good. I didn't have to worry about restarting or anything and starting was super easy. I did however have a powerhead with a hose always in the tube (a small bit of tubing from the top "nipple" for lack of a better word with tubing going from the powerhead, to the inside of the U tube took out any air immediately and started the siphon very fast....and it ran really well. I had no complaints but now all my tanks are drilled as it is just plain easier!