How to install an overflow box and drill an aquarium.

[Big Larr]

Another view

 

[Big Larr]

After drilled before painting the back

 

[Big Larr]

1 drain is full syphon the lower one and second is at water level to surface skim and act as an emergency drain just in case and I used 1" drains and a 3/4" return

 

[LetItReef]

1 drain is full syphon the lower one and second is at water level to surface skim and act as an emergency drain just in case and I used 1" drains and a 3/4" return

I see. Thanks!

 

[Big Larr]

Here is how I did the surface skim/ emergency drain