Lighting question

[kingfish]

Are actinic lights nessassary for coral growth and development? I currently have 150 Watts of 6500K lighting over my 20 gallon frg tank.

 

I want to set up my frag tank for growth not color. With that being said, I don't want my corals to loose any color.

 

Would the 6500K lighting be enough lighting? Do I need any actinic? If I need actinic please explain why.

[Caribbean Jake]

it is a matter of opinions.

you do not need the actinics for growth, but they do assist on the dust & dawn cycle, providing the blue color of the skies. others will say, yes it is necessary.. but again it is a matter of opinions. The tank do looks nicer when the MH are off and the Actinic are on, gives you the sense of serenity when daylight life is about to go to sleep or wake up....

[dbartco]

all personal preference. Your growth should be fine.

[copps]

Actinics are absolutely not necessary... however, with only a 6500k bulb you will lose alot of certain color pigments. If you are not concerned about heat output (ie this is hooked up to a larger system and the bulb will be run overnight), you could pin the pendant very close to the water surface with a higher kelvin bulb and still get high PAR to grow your frags at a good rate with good color... I am a 10k with actinics man on my large sps display, but my frag system has unsupplemented 20k bulbs because I don't have actinics and the 6 foot frag tank is shallow...

 

To answer your question simply, actinics are not necessary, but you state you don't want your corals to loose color... so they will be necessary unless you go with a higher kelvin bulb...

[Prunfarm]

If your frags are going to be for sale or trade, they will not show their potential colors in pics or to the naked eye. A higher kelvin, or maybe an actinic to use soley for pics etc., may help. Just my .02