Actually increasing the blue spectrum will have a decent impact on PUR (photosynthetic usable Radiation). Light visible to us really has little impact on usable PAR to our corals. What I mean by this is that a tank lit by mainly blue/UV spectrum will not look like it has much PAR as a tank lit by less Blue/UV and more white/yellow light.
Letās make up some number to help visualize the point Iām making in the above example. Letās say we measure PAR on your tank with the light setting you have now and get PAR reading of 200 and PUR reading of 65% at 10ā in your tank. Now we turn up your Blues and UV and retake PAR and PUR readings again. Both readings should go up, PAR slightly but more significantly PUR. For the sake of comparison letās assume PAR stays constant but PUR increases to 75%. This would result in an increase of usable PAR from 130 to 150, if we included the change in PAR then this difference would be greater.
White/yellow light is efficiently used for photosynthesis in plants (algae) and blue/uv light is efficiently used for photosynthesis in corals.
My thought is add more blue light and back off on the whites to only whatās needed for your personal viewing preference. Personally I run my tanks with no white/yellow spectrum but thatās my preference. Also I see less chance of undesirable algae outbreaks.
Just my thoughts, hope this helps.