i would get timers for your lights, there pretty inexpensive and there great, just set the time u want it to turn on, then set what time to turn off and plug ur light wire into the box and wolah, done, that way even if you are in town but forget to turn the lights off, besiesd by setting it to turn on and off at x time, the fish get into a habit of knowing when its time to go to sleep, and wake up, but if this cant be an option, try someone like a neighbor or family member to tank sit, and if thats not an option i dont know what to tell ya