Protecting a Closed Loop Intake

[Jaws]

The only thing I would be careful with when running it in an overflow is sometimes bubbles from the falling water and foam end up in the overflow and once they go through a pump on a closed loop, you end up with thousands of micro bubbles. JMO

[TheReefGeek]

And carefull you dont run your overflow dry because you dont have enough linear lenght of overflow to keep up.