I want to have 3 separate waterfall weirs, 24", 18" and 12" with lots of water at an average elevation of 7'ft. I would like a remote pump and U.V. filter. I was thinking of using 3 separate 2" pipes to feed the falls.The pond will be relatively small, 5' x 7' x 2'ft deep plus a 16' pebble stream bed leading to the hidden return. I really want an impressive amount of water from the falls. Any ideas on how to size the pump?