T5/XR15 PH question

[Panicked Reefer]

I have a 75G with 2 XR15s, 2 ATI Blue Plus's and 2 ATI Attinics. My XRs go from 12pm to 12am running AB+ @35%. The T5s are on from 2pm to 9pm. My corals look noticeably happier when the T5s are on. My PH "bump" drops off when the T5s turns off. Would I benefit more from turning up my leds or increasing my T5 time?

 

[blaxsun]

Maybe. pH goes up and down over a 24-hour cycle.