Recently I have setup a 29 gallon tropical tank and am curious to know if it is unhealthy for my fish to have my lighting on at two different times of day. Since my wife and I work two different schedules with her on first shift and I am on second, I wanted to possibly have the light on from about 9am - 12pm then from 4pm - 10pm so that we can both enjoy the tank. Right now I get about an hour and a half of a lit tank per workday and want to enjoy them before I go to work. Will this mess up the fishies night schedule or should I just leave the light on for 13 hours a day? I have a timer on my light so I could set it for multiple intervals.