of course, u just have to be out of a gravitational field lol.
on the earth we have gravity.
so if we had some water in a pool right, and a pond say .5 metres higher then the pool, then we could have a little channel to make the water go back into the pool. then it is powering itself, impossible. if we could do this then our renewable energy would be resolved as we could build many turbines, and as the water is flowing from the pond to the pool again then its turning the turbine, making a current, this would go on forever and so we are making energy violating the conservation of energy.
when ur in space where there is 'no' gravitational field then, if u had a pool of water then syphoned it 'up'(well up is only relative to an object) then the water would just keep going once u provided the first 'suck'. so ur not gonna get a continuous flow.
those answers are only my opinion, i don't know for sure, but just thinking about it i'd say its a very logical answer which would suggest i'm right