Ok reading all this and I've got to say , a lot of wrong info here. Alk has nothing to do with color first of all and for growth it doesn't matter hi or low alk . Growth is achieved from less stress . In other words stable parameters if you can keep alk cal and mag steady all the time you will get fast growth. As for color your po4 are way to high, are your sps brown you would like to aim for 0.00 or 0.02 . Do you us a RODI if so whats your reading coming out your RODI filter it should read 0.00ppm