T5 help

[Odysi]

Hey guys just looking for some help on my lighting. Im running a 6x39W ATI dimmable fixture over my 40B now got rid of the leds. I have had the light for 2 months now but just can find a good placement for it yet. Its 9" above the water line right now and running max 45% on C1 and 55% on C2 but i dont feel its enough light at the sand but when i increase the % anything that is mid way in the tank like Sps have bleached. I know every tank is different but im just looking for suggestions where i can maybe start.