light duration

[Kraken]

I am running 10 bulb t5 fixture, and I have all my lights on for a good 7 hours. I leave the moonlights on for another 5 hours for my "viewing pleasures". Im already pushing it. Just be sure you dont run it too long, or else you will start to get algae.

[Aquattro]

As I mentioned, I would run them 7 or 8 hours max, so count backwards from bed time and have the lights come on then. Doesn't really matter when the 8 hours happens, so if you need to have main lighting come on at 6pm, fine. My lights ramp from 1% over night, go from 1 to 100% by noon, start ramping down at 8pm so that by 11pm they drop back to 1% overnight.