Im currently setting up my 1000gal pond which is build up 2 foot above ground level by brick and then goes down 2 and a half feet below ground level. does my pond filter have to be above the water level in order for it to work? or is there a way i can get the filter to sit on the grass then get pumped up a pipe and return the water to the pond that way? this is purely because my filter will look pretty ugly and ruin the pond if it just sits on top of the brickwork. Thanks in advance.