Randy, I have 2 hydra 52 HD’s over my 50 gallon cube. Your hydra 52 setting produce 650-700 par with my 2 fixtures. Will the spectrum shift if I reduce the sliders proportionally?
If there were any shift I wouldn't expect them to shift dramatically, since we're really talking about changes in intensity rather than changes to spectrum. I'd personally be comfortable running a proportionate intensity to these settings over my tank.