Lights 6.7K and actinic ratio

[tanker]

It is time for me to change PC bulbs in one of my tanks. I currently have 2 6700 bulbs and 2 actinics. Would it be better if I have 3 67oo and only one actinic?? Are there any advantages, or problems with this?? Or just go back to what I have??

[kmk2307]

Hey tanker,

I think it depends on what animals you want to keep and what you want the tank to look like. You might get better growth with more 6700 Kelvin bulbs but the corals may appear more brown. The actinic makes things appear more blue and may also stimulate zooxanthellae in corals to be more flourescent. I'm not sure if it actually changes the zoox or just causes it to be less packed in the coral but I know that more blue light tends to promote color in corals. I have two 250w 6500K metal halides and 2 96w (i think) actinic blue vhos on my reef fwiw.

HTH,
Kevin

[xfactor]

blue in genral help colors while 6.7k - 10k help growth.

its all up to you really but I wouldn't go below 6.7k.

[1234]

I too have the Iwaski's - 6500k bulbs with 4 URI super actinics, nice coral growth, very bushy polyp extension on the sps's. Great growth on corals, too. Best par for the buck, and the bulbs last up to 2.5 yrs. :D

[kmk2307]

High five 1234 :)

I am also really happy w/ my iwasakis. Do you have a picture of your tank? I am curious what mine would be like if I added two more VHOs.

Thanks,
Kevin

[stolen_pass]

Q. What's the difference between a "Blue 7,100K" and "Actinic 03" bulb?
A. Excellent question! OK, a little background: The original "Actinic 03" bulb was made by Philips. They were not made for aquarium use, but were adopted once news spread about the beneficial aspects of using this bulb over reef tanks. Nowadays, "Actinic 03" has become the marketing term used to identify "blue" looking bulbs. Many bulbs are passed off as "actinic", when they are just a blue bulb.
So, to answer the question, Blue 7,100K bulbs are visually brighter than HelloLights Actinic bulbs. Blue bulbs will NOT fluoresce your animals as well as our Actinic bulbs. Many others sell "actinic", but they are really selling blue bulbs. The phosphors coating the interior of our Actinic bulbs are specially formulated to produce a narrow spike of concentrated violet/blue light. This is why they appear to be more faint than blue bulbs. If you have tons-o-corals, then we suggest going with Actinic 03. Remember, a visual measurement of a lights utility is a poor one.


The look better too. :D My 03 True Actinics are more a purple than a blue. I found a great discussion a while ago on how the blue tint they use actually robs the actinics of the usable light in the spectrum. I'll see if I can find it again.