Advice Required for lighting periods

[globaldesigns]

Hello Everyone,

I had a wierd thing happen this summer, lost many sps frags and colonies. Everything was perfect, even had Kevin @ Red Coral do testing... But still it happened. Things have stabilized and corals are slowly coming back.

My question is about the lighting period. I was lighting for 11 hours a day, continously. I have 2X250W MH with 2x5ft T5HO... I just changed it last night to break it down to 9 hours total, a 4 hour period (8am to noon) then a 5 hour period (5pm to 10pm). This is a total of 9 hours.

With this new timing, I have removed 2 hours, plus gave the corals a 5 hour break between lighting periods, just in case things are too much.

I want others advise, what do you think?

Specs:
Hamilton Belize 5ft fixture
2X250W MH
2X5ft T5HO
MH bulbs are 10K ushio - Love these as they are very white, no yellow
T5HO are Hamilton's that came with it - Actinics

Please note that fixture and bulbs are about 6 or so months old

Thanks for any advice in advance.

Rick