question about actinics

[copeseter]

Do actinics make the corals color up more or are they just for our viewing pleasure? Why I ask is I run my actinics earlier and later than my halides even when I am not home. I thought if it was just for my enjoyment I would just run them when I am vieiwing. But if they help the corals obtain a better color, I will leave well enough alone.

 

[mr_x]

no.they don't color them up. actinics make the corals look better. actinic lamps have some colors that corals utilize, but you are probably getting this part of the spectrum already, with your daylights. i simply use them to make the corals glow a bit more, and for morning/evening transitions.

 

[aztec reef]

The reason for actinics is to mimic sun rise/sun set. just like Nature..

 

[reefkprz]

IMO/E actinics are utilized by corals especially deep water or low light corals, as well as corals deeper in your tank, running a light at 420-460nm wavelength allows deeper light penetration of a utilizable wavelength, water blocks red spectrums first, blue last so runnign actinics can allow photosynthesis to happen deeper in the tank, while not a very intense light it is a good supplemental "feeding" of light.
plus as others have mentioned thay can make your tank more appealing by balancing out the yellow or white look of other spectrum bulbs, as well as making any corals with the tendancy to flouresce show its colors. it doesnt change the corals colors but tends to acentuate existing colors.

 

[aztec reef]

Imo, you need actinics, wether you have high-light intensity corals or low-light intensity corals.
The reason is simple, In the Ocean there's no actinics. just Sun light. which in our enclosed system we try to mimic with mh's..
Now imagine if the Sun just came out (at full spectrum)all of the sudden without any daylight in the morning, and at night Sun goes away without lunar ligh, into peach black. you guys ever seen an Eclipse?
We cannot lower/raise the Mhs intensity throughout the day . just like the sun rises from its lowest to its highest point....
once we turn mh's on, they stay on at the highest intensity spectrum untill going off. So you need the supplements of lesser lights (preferably flourecents/actinics) to regulate photosysntesis .
Every life organisms needs a specific lighting intensities/spectrums to regulate their life processes, even though mh's are white in spectrum, they're composed of a broad band of colors which cover the optic spectrum..
That said, in controlled ecosystems(like our tanks) corals and other organisms respond better to the amount of light received, rather than the spectrum it was delivered..
The reason why low light corals utilize actinics and most of blue spectrum its because thats all they been exposed to or can reach. the reason is : they're deep in the Ocean....

Unlike most corals in reefs which are mostly in really shallow waters...(2-10 feeet). the deeper you go dowm the darker.

 

[robdog696]

I found this post very helpful!

 

[stanlalee]

actually 420nm ish is what corals use to build their protective pigmentation which protects them from UV and getting scortched so yes it is "functional" and not just there to make your 10k bulbs look better (460nm is far more effective and visable for coloration but less functional to corals hence not as popular as 420nm. current pc bulbs have one tube @ 420nm for function and one @ 460nm for looks). You dont need actinics though, even a 6500k bulb has adequate blue spectrum content (just not spiking there) so WE primarily add actinics for looks.