Lighting question: How often should they be replaced?

[shrimpchips]

Originally Posted by Ephraim

actinics i change when they burn out, they give off little usable light, if any, for the corals anyways.

A lot of the 'blue' bulbs now actually have a fair amount of PAR.

Your could always use a PAR meter to track the output of the bulbs, but I suppose that wouldn't catch any spectrum shift.

The recommendation seems to be around the 9 - 10 month range. 6 if you're made of light bulb money.