Lighting Requirement

[Limpc]

Hi all,

2 questions:

1. I have my light turn on for about 12 hours per day. My light is a combination of PLs and FLs. Do I switch off all light after the 12 hours or should keep the actinic on ?

2. Besides the enhancing the appearance of the aquarium with actinic, does it serves any purpose in terms of coral upkeeping ?

Thanks for any feedback.

Rgds,

Limpc

[Tanzy]

I would suggest that you turn the actinics off as well with all other lights because the actinic is still considerably bright. You might want to extend the actinics for one hour before and after the main photoperiod for so called dawn and dusk effects but it is unnecessary and have not been proven to be beneficial or detrimental to the health of the livestock.

Actinics supplement the blue spectrum of the lighting to simulate the bluer water of the reef because light of other wavelengths tend to be absorbed by the water. This is based on the assumptions that since corals live in an environment dominated by blue light so it is good to give them more. This is hotly debated among other topics as the the actual benefits it provides because it has been shown that growth rate is dependant on light intensity and not spectrum. The experiments found that coral grew at the same rate under 5000K lights as other spectrums.

The major reason for actinics is aesthetics because some reefers prefer a cooler blue look and from the fact that some coral pigments fluoresce green under actinics.

[hongqixian]

The extra just actinic period also does great for coralline alg as I've heard.