just FYI I have a couple maxi jet 600's and a couple 1200's and I can hardly tell any difference in the flow of the two. I can put my hand in front and move it close or further out and the flow is nearly indistinguishable between the 600 and the 1200, I have a korallia that's rated at 425 gph
, and an odyssea 250gph also and the korallia ( which has the highest gph
rating) is by far the weakest flow wise. This is all of course by my five finger flow meter in a 47g column tank.
Also as far as flow goes I have Trouble with the shape of my tank with striking a balance between getting enough flow in certain places and no dead spots and not stirring sand or creating little whirlpools that let air into the power head and makes an annoying slurp sound.