maybe you shouldn't turn the lights off in the tank if the room is mostly dark, but as long as there is some amount of ambient light in the room the fish still get a day/night light cycle. someone explained it to me like this: in nature fish do not live in clear, highly lit water sources. they live in algae filled ponds, dark marshy waters, etc. yes, they still get some sunlight filtered through but it is nowhere near the amount of light that they get from an aquarium light.





