I have 6 400 watt halides abouve my 500 gallon cube with Luminac III reflectors and 8 t5 actinic's. I recently had to change out my timers on my lights and for the life of me cannot remeber the length of time they stay on. That got me thinking how long does everyone else run theirs. My t5's come on around 10 am and shut down at about 10 pm.