Originally posted by Liath
I have heard that you should have a 10 to 12 hour photoperiod no matter what the wattage, but I don't know for sure if that's true. Leaving the lights on too long will definitely result in an algae bloom, and I do know that plants need a good nights rest just as much as I do.
Yep, that is exactly what I've heard too.. 10-12 hours of light but not too much or, as Liath mentioned, it will result in an algae bloom.
When I first got started with my fish tank, I always left the lights on so I could watch the fish. I started noticing algae growth all around then finally realized it was caused by so much light. Plus fish need to sleep too and some fish (like my pleco) eat at night.