need a "little" help

cause I already have to koralia 1's rated at 450gph each. and a "squid" will only switch direction of flow from a direct flowpower head(witch is harder on fish and coral where as it is like a jet of fast moving water) my koralia moves large voulums of water with a wide direction. if you put your hand in front of the power head at 450gph at wont feel like a jet, its more like "water wind"

Are you building a slow-motion hot tub?
The only sweeping resistor I can think of is a fuel level sender from a car's gastank, immersible in the tub. If you want to build a miniature wave pool, you are on your own.