The Koralia Magnum Series of power heads includes pumps 5-8
Model - Flow Rate - Watts - Recommended Tank Volume
5 Magnum 1,650 gph 8 4-1/4" x 6-1/2" 110-180 gallons
6 Magnum 2,200 gph 10 4-1/4" x 6-1/2" 150-250 gallons
7 Magnum 2,700 gph 12 4-1/4" x 6-1/2" 180-300 gallons
8 Magnum 3,250 gph 19 4-1/4" x 6-1/2" 220-360 gallons
I have the magnum 8, let me tell you its a LOT of flow, every hidden piece of food and poo that my other power heads couldnt take care of, where stirred up, fish are now swimming rather then milling around. my biggest thing to harp about it is dead silent.
they have better flow rate with comparable tunze and vortecs and less electrical consumption, where they falter is their obvious size, the 8 is the size of a large orange to give you a better idea.
I like em, I snagged two 8's for less then 100 each, so there I go. love em, would recommend them.