[Carol]

I have room for 4 VHO 110W bulbs and when I run all 4 10,000K is seems so much brighter than when I change one of them for an actinic. I have a 55G tank. Do I really NEED actinic?

[CaptainK]

Hi Carol,
Do you have any corals in your tank? If so let us know what kinds you have, some corals need the particular spectrum of lighting that the actins give off.
If you have just fish then I think you should be OK with the lighting you have.

-CaptK

[organicreefer]

no you dont need actinic,most people just like the way it looks

[CaptainK]

organicreefer, I am not sure how you were coming across on your post but were you saying that corals do not need actin lighting?
I always thought that actin lighting was needed for the health of our corals and inverts?
Have I been thinking wrong about this?

-CaptK

Sorry to butt in on your topic Carol but I just want to get this right.

[newreefman1]

actinics arent needed cap. They are eye pleasing but they also add additional intensity to our tanks too...so they are mutually beneficial.....tanks with lower K bulbs, might need more actinic help to get to the right K rating but Im talking about bulbs under 6500k.....and most of us dont use them for corals anyways..anything higher than 6500k daylight is just for the eye

J

[Carol]

Hey, no I don't mind more questions - I want to get it right to. I have been researching this and can't seem to come up with any straight answers. My concern is that I don't have any halides and don't ever want to have them. With the new 10,000K VHO bulbs I am wondering if I can support some corals that were once thought to only live under halides. On my 55G 4 VHO's are pretty bright. I called the manufacturer to find out just what the lumens are on the 10,000K versus the actinic. Just as I thought - the 10,000K has 5500 Lumens per bulb and the actinic has less than 10. That is a substantial difference in brightness and it is very obvious to me when I look at the tank. Now I know that actinics are supposed to penetrate water better but my distance from bulb to sandbed is only 22". So, I want to try SPS corals but I would like to think I can have reasonable success and not just kill everything. 4 VHO 10,000K bulbs give me 22,000 total lumens and the 10,000K's have a lot of blue in them. Any input here?

[newreefman1]

ive changed my attitude a bit on things....and think that a tank lit by just vho's is great for many montiporas and just a few acroporas..but pretty much anything else...as for predominantly stonies though, mainly acroporas metal halides are still the preference and preferred for substancial colony growth as well as more vibrant coloration...

VHo and MH is a great combo however.

BTW, the vho's spectrum is spread over 4-6 feet of length. The Metal halide is far less, providing it over 2'. Thats one benefit to the halides.

J

[organicreefer]

sorry i didnt reply back sooner havent had much time to post the last week or so,took off early today
anyway,i think there have been some studies that show that actinic lighting,420-440 nm,i think?,is benificial to some corals,and it makes some flouresce in a very cool way....
i also think there have been studies that show it doesnt really matter either so..
i like my light a little on the blue side ,and i really like my dusk/dawn actinic light periods too .
but as you pointed out actinics arent very bright ,and if youre focus is on light loving hard corals,you probly should leave them out .jmo

[scubadude]

Heres an interesting thread on this subject

http://www.reefcentral.com/vbulletin...ght=NO+actinic

IMO no you dont need actinic supplement, its purely aesthetics but can make some of your corals look "cooler"

[bowfront]

You might want to take a look at this recent article by Dana Riddle. He found that the rate of photosynthsis was about the same under a 4000K bulb as a 12000K bulb both of the same intensity.

[Papa Doug]

Bowfront, I agree with that. I have used both a 400w 12K & a 43K. The corals dont give a hoot.

But the algae does. It loves the lower colour temp. Also a very important part of it, is the colour of the corals. This is one reason, Dr. Mac uses 20K bulbs, as an example. After all the bulbs I have tested, the best colour I can get from my corals{plus growth}, is from a high "K" bulb, like the 12K. The problem is, as mentioned before, is the intensity is lacking, so one must run multiple bulbs, or as I do, supplement the 12K.

Another example. I have a friend who runs a pair of 250 watt Iwasaki,s, as I once did,{ the best overall lights,IMO}. His sps tank was doing well under them, as it should, but when he added a pair of 96watt actinic pc,s the growth took off like crazy and a much nicer colour.

As I have posted before, from my experience with bulbs, for any normal sized 4 ft tank, I would run a pair of 250w Iwasaki bulbs, along with a pair of 110w actinic vho bulbs. I find the 250 version of the Iwasaki to have the nicest crisp white I have seen, much better than my 400 watt Iwasaki.

I sort of run mine in reverse. I use 4-40w 65K GE ultra bulbs for white light & a 400w 12K Sunburst for actinic colours, and of course, to increase the intensity.

[organicreefer]

ive used a 43k in the past myself,as well as 12k ,10k ,55k and 65k.ime, the corals will adjust to any of the bulbs,but they do all have their "preferences", imo.very high light loving corals do great under the 43k and 55k bulbs.never had sps under them but im sure they would grow awesome.low-medium light corals tend to get pale and look ugly, imo,and "do better" under higher k bulbs without a doubt.
also, as i think doug was getting at ,the biggest thing different color spectrums do is effect the color of youre corals=redder the spectrum ,the paler the corals,at least ime..and i also agree about the algea too.
ive tried alot of bulbs ,and im sold on 10k with actinic. everything tends to look" the best "and they seem to "do better" over all,at least ime, with the corals i have (mostly softies and lps).