It's summer in Alaska, and we are getting around 18 hours of daylight now. I have been slowly adjusting (increasing) the light time in my tanks all spring to kind of coincide with the natural light. I figured, why shut off the lights in the tank when the sun is still up? The fish are getting about 15 hours of light now. I have no algae problems and everybody seems happy. Anybody see a problem with this? I'll adjust back down in the fall.