Actinics - how important are they?

[Jenn]

This may be a newbie question, but I would like to know how important actinic lighting is and what actual purpose it serves. I would like to know how important it is to replace my actinics w/ the rest of my bulbs every 6 - 8 months. Thanks everyone.

Jenn

[Tim Marvin]

Very important. The actinic is one of the main colors the corals use. Depending on how deep the coral lives in the ocean determines how much of the actinic it lives off. Blue is one of the last colors to be filtered out by the water, and red is the first. Red is lost in like the first 5 -10 feet of water depending on turbidity. At 30-100 feet the water seem really blue and we use a dive light, even in the day, to see the true colors of corals. So, Yes change the bulbs.

[Instar]

Photosynthesis is dependent on light in the blue spectrum. The eventual colors of animals may depend on a wider spectrum, but, they can't develop without photosynthesis from the blue light. This and Tim's answer are the long way of saying that blue light is imperative! If you use Coralife actinic 03, the manufacturer (reefers) say they last for 12 months. I believe I read a study on that in agreement. I can see the deterioration in other bulbs in 4 months with my eyes and the bulb ends are dark. The Coralife are not the same. They are not as cheap as the other bulbs either.