What lighting and photoperiod did you have? Shortening the photoperiod is an accepted way to acclimate to stronger lights, but how much will depend a bit on what you replaced.
To answer your other question, I run T5 actincs for 10 hours, metal halides for 9.
I have my LED's come on at 10 and kick off at 1:30. Thats when my MH come on, they stay on for 6.5 hours and then kick off. After that, LED's come back on until midnight.