Actinic lighting is beneficial to stimulating zooxanthellae and providing corals with energy. It is also beneficial to have some actinic lighting to replicate the deeper water reef light conditions that ocure naturally on the not so shallow reefs. Actinic lighting isnt a big factor on shalow reef corals, but beneficial to all, especially deeper water corals.
The lower K rated bulbs (like 10k) are, for the most part, the best for growth. Actinics arent necesary, but do play a roll in reefkeeping, and make our corals "pop" and is pleasing to the eye.
But, just a jojo stated, unless you get some heigh quality actinic bulbs with a heigh PAR rating, actinics do very little for growth. They for the most part just help with synthesis and replicate deeper water lighting conditions.
Last edited by Sir Patrick; 11-16-2009 at 09:59 PM.
Reason: I typed heigher instead of lower.....oops! sorry...fixed