gravity fed skimmer?

[mistermismatch]

i was thinking about making a DIY skimmer untill i have the money for a real one. i was wondering if it were possile to have the intake into the skimmer piped into the end of my overflow instead of using a pump or powerhead???? ive read that skimmers only need the flow of 2x your gallons ever hour. is this true. if so then im guessing the overflow would be too much and cause the skimmer to not really work. any help???

by the way my overflow is a 3/4" pvc siphon if that helps at all