I have been reading the posts and have noticed that it seems like the lighting is important. I thought it was just for decoration. Anyway we are just using the lights that came with the tank. I don't keep them on but for about 4 hours a day. Is this ok or should I leave the lights on more. So they really serve a big purpose?
Your fish need 8-12 hours of light per day.
1. Algae will grow and is not bad to have a little because algae is photosynthetic and will help put oxygen in the water. Algae will also provide food for microorganisms which the smaller fish like tetras will constantly be "grazing" on.
2. Light triggers instinctive actions in all organisms. Your fish are programmed to behave certain ways depending upon the intensity of light.
3. The various color patters and stripes exist to help some species of fish to school. Without light, the fish cannot see the colors and cannot form their instinctive schools.
4. Fish need a predictable schedule and the on/off of the lights help in maintaining that schedule.
Always put your light on a timer so it goes on and off at the same time every day.