I have been thinking about building a little skimmer like those ones you see with a rio 1200 that hang on the back but i was wondering if these kind even work that well the ones iv seen dont produce much in the way of super fine bubbles i think i could mod my return line to do as well wtihout any power, has anyone ever heard of a gravity feed skimmer not requiring a pump just askin ive been curious im a dork like that