Yes... the water flow is very dependent on the design of the power head. The bottom line is that the actual movement and flow of water is rarely what one is expecting... otherwise it would be too easy to get good circulationHi Arcturus,
These Kh and Gh values are from my test (API Test kit). About the diffuser, I moved it below the power head but the result is not what you expect The bubbles are going behind the power head straight to the top. I have to stick the diffuser to the front glass in order to work. It doesn't look good but i will leave it for now just to test.