Originally Posted by tcarola154
out of curiousity... why do people recommend doing that? in what way is it beneficial?
Two reasons. One it allows the pH to remain stable 24hrs a day. During the night (lights out) pH typically falls off, while in the day time (lights on)the pH typically increases. This has to due mainly with algae consuming CO2
during the day with causes an increase in pH. By having it so that the fuge is lit when the tank is not, you decrease the pH swing in the tank.
Second reason to keep the fuge lit continuously is that many macro algae like to go sexual. What this means is that if one is not careful, it is possible to have a macroalgae bloom and end up with the stuff everywhere. Keeping the lights on the macro 24/7 typically will prevent a bloom from happening.