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FAQs about Actinic Light and
"Blue" Lighting for Marine Systems

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Related FAQs: Lighting Marine Invertebrates Coral System LightingSmall System Lighting, LR LightingTridacnid Lighting

Is the photonic energy from "actinic" lighting necessary? No. Amplexidiscus fenestrafer

Re Guys I need advise/help/decisions on Lighting, fluor.       4/29/13
Hey Salty getting back to you about that light bulb you wanted me to  swap.
<OK>
Salty if I get that blue you recommended that would put me with two  blue in my fixture.  I only have two bulbs in my zoo med.  I have the  blue actinic Coralife 10,000 T5 HO bulb and if I get another blue as you suggest  that will leave me with no white????  I am confused.
<A Coralife 10K is not what I would call a blue actinic unless you erred in your description "Coralife Blue Actinic 10,000K".  The UV 14K lamp will look  more like a crispy white/blue, will not appear real blue to your eyes.>
 I want to do  soft corals Salty.  Oh btw, I lost my anemone to a filter intake tube suck  up .......
<Not uncommon at all.>
I was on vacation and hub had NO idea what to look for inside my tank,  it's  my fault, I never should have gone with a anemone in this small tank with two corals fcs.......I loved that darn thing, I had fed it twice and it was  thriving.........I just don't listen, I am bad and I felt horrid losing that damn  thing.  Thanks again for the light bulb response.   Julie ; -  (
Re Guys  I need advise/help/decisions on (anemone) Lighting 4/29/13

Hey Salty getting back to  you about that light bulb you wanted me to  swap. 
<OK>
Salty if I get that blue you recommended that would put  me with two  blue in my fixture.  I only have two bulbs in my  zoo med.  I have the  blue actinic Coralife 10,000 T5 HO bulb  and if I get another blue as you suggest that will leave me with no  white????  I am confused.
your description "Coralife Blue  Actinic 10,000K". The UV 14K lamp will look more like a crispy white/blue,  will not appear real blue to your eyes.>
I want to do  soft corals  Salty.  Oh btw, I lost my anemone to a filter intake tube suck   up .......
<Not uncommon at all.>
I was on vacation and hub had NO  idea what to look for inside my tank,  it's my fault, I never  should have gone with a anemone in this small tank with  two  corals fcs.......I loved that darn thing, I had fed it twice and it was thriving.........I just don't listen, I am bad and I felt horrid losing  that damn  thing.  Thanks again for the light bulb  response.   Julie ; -  (
Re Guys I need advise/help/decisions on Lighting     5/3/13
Salty thanks on the response about the light bulb.
<You're welcome Julie.>
 I have a question  though,
with the recommended light and the one I have, can I ever possibly do a  anemone again?
<Possibly a Bubble Tipped.>

Would I have enough light for a carpet anemone?  I saw  one and I would like to try it again perhaps.
<Mmm, lighting, tank size and lack of protein skimmer tells you no. 
Anemones are difficult to keep for any length of time, especially a Carpet Anemone which seldom live more than six months even under optimum conditions.  Best to spend your money on a good protein skimmer.  Have you read here?
http://www.wetwebmedia.com/ca/volume_6/volume_6_3/capranem.html>
As always, thanks a  million. 
<You're welcome.  James (Salty Dog)>
 Julie
Guys I need advise/help/decisions on Lighting/Now Brain Coral/Systems 5/3/13

Salty ( UPDATE)
Well..........nix that idea on a carpet anemone for heavens  sake!!!!!! 
They get huge and need 125 gallon plus size tanks.
<Yes indeed.>

 I did get a brain though Salty.  I  don't know what the name of the brain is called though but I will ask a few forums if somebody can ID it for  me. 
Salty as far as your knowledge on Brains go lol, where do they like to be located inside the tank, I am  hearing a lot of on the bottom sand etc.
<Yes.>
I have sand/crushed coral in that sand, what say you on  this?
<Most brain corals require moderate lighting so you would be right on the edge with your present lighting. >
As always many thanks for helping me along here.  I am going to consider an LED fixture over  buying T5 bulbs now, I think in long run it will save me time and money etc.
<Oh, most definitely, will pay for themselves in energy savings and lamp replacement costs.>
 If I send away for just  one bulb they are going to charge me bulb handling fee of $20 dollar and some places $25 dollars.  LED's  are so pricy to start off with though, I am hoping my money tree out in my yard bears nice dollar bills for spring here LOL.
<Good luck, mine hasn't bloomed in years but my tree was the $20 bill species.  I believe the $1 bill species is easier to care for.  James (Salty Dog)>
  Julia ; - )
Re: lighting, pumping, and new tanks oh my! James! LED input please   5/3/13

This is just for my info, correct?  Looks like I answered all his questions re
LEDs.
 James
<Ah yes. As is my habit when others are mentioned positively, I cc'd you re. B>

Lighting question: 20k vs. actinic bulbs   3/19/13
I am planning a move up to a larger reef aquarium with softies and LPS and considering lighting options.
<What size display?>
Currently I have a very nice Aquaticlife t5 HO 4 bulb fixture with (2) 10k bulbs and (2) 20k bulbs in place of the actinics.
<How long have you had this fixture?>
 I love the look and the corals have done well. The 20k run 14 hours, the 10k 12 hours. What do you think of this set up?
<Firstly, not all 20k's or 10k's are the same as one another. Some will hold their spectrum much longer/better than others.>
Do you see any potential problems? It seems to me that 20k bulbs have more usable light than actinics, but I do admit that I find the whole lighting issue somewhat confusing.
<Haha it sure can be can't it. Some of these new full spectrum LED's are even more complex. Not all actinics are they same either. There are 50/50's, 75/25's etc, the lighting combinations you can have are vast>
 Thanks for your input.
Karen
<Your 4 T5's could be a ton of light for a shallow tank or they could be really inadequate for a larger tank. Lets figure out what size range of tank you will be upgrading to and go from there. NateG>
Re: Lighting question: 20k vs. actinic bulbs   3/19/13

Sorry about that. I am moving from a 46 gallon to 75 gallon. I got the fixture three months ago. The 10k bulbs are original, the 20k are Giesemann that where put in January.
<Nice color mix. I bet that looks great>
The fixture is 36 inches long, the new tank will be 48 inches long.
<Unless you raise the fixture a solid 6+ inches off of your tank, your top corners will be without light. Some people even prefer this effect. You should have enough light with your 10k 20k combo to have some less light demanding corals by your sand. I wouldn't recommend 2x 10k and 2x actinic over a 75. Especially if its a 36" fixture.>
Karen Adam
<If you find yourself in the market for a larger fixture, it is well worth the investment for some nice full spectrum LED's. No more of the $80+ a year in bulbs right. Less heat, less ac, less electricity=more $=more frags! NateG>

Actinic light output   3/10/13
Hey guys,
I don't own a PAR meter or anything else that can measure light/lumen output so I was wondering if someone can tell me, how much usable light/PAR/lumen an actinic bulb produces, "ballpark" percentage wise, compared to it's daylight counterpart of the same wattage.
<Most all useful (photosynthetic, PAR/PUR) light/photonic energy is in the green to red end of spectral range. Answer for actinics, is that depending on the bulb, very little usable light is produced by actinics... they're mainly for looks. Some are intended to produce "fluorescence", the re-release of light in other spectra... but this too is non functional in terms of photosynthesis>
Reading the FAQ's, I see that actinics are mostly for aesthetics and don't provide great benefits to coral however, when my actinics come on in the morning all my coral do open up, so they are obviously receiving some level of light from the actinics. Thanks, Art.
<Welcome. Bob Fenner>

Actinic Lighting Specifics/Reef Lighting   4/1/12
Hi Crew:
<Hello Jess>
I just purchased these new lights (in the below link), as a supplemental/actinic lighting for my 220gal saltwater reef. I have 3, 250w MH and LED Lunar lights as well in the canopy. I had 2, 96watt VHOs in there as well, but these burnt out so I am wondering if these below will be ok to replace them.
<You stated "as a supplemental/actinic lighting for my 220 gal saltwater reef".  There is no actinic present in any of the four available models that I viewed.  I'm certain that with an individual LED wattage of 0.056, there will not be much useful penetration for photosynthesis.  The 3700 and 4200 Kelvin models would be of no use at all. It would take 54 of these individual SMD diodes to equal the intensity of one, 3 watt LED.  Do not confuse intensity/brightness with PAR/PUR, they are two different worlds. 
A 400 watt, 4200 Kelvin metal halide lamp appears very bright to our eyes and has a high PAR value, but is of little to no use for growing corals as far as PUR (photosynthetic useable radiation) is concerned.  A 4200K lamp has an approximate wavelength of just over 700nm, higher than what would be useful for coral growth.  For you and others who may read this post, there is a relationship between a color temperature and the peak wavelength in it's spectrum. It's called Wien's law.
Wavelength (nanometers) = 3,000,000/Color temperature (Kelvin).>
Thanks!
<You're welcome.  James (Salty Dog)>
http://www.creativelightings.com/LED-SMD-T8-Tube-Light-4-foot-300LED-17W-CW-p/cl-smdt8-4-cw17w300-ul.htm
Jess
Re Actinic Lighting Specifics/Reef Lighting 4/2/12

Hi James,
<Jess>
Thanks for the quick response, I was able to cancel that order in time thankfully. Right now I am running 3, 250w 14,000k mh, and I have LED lunar lights that I just installed. I am super confused about the actinic lighting, although the discussion boards have helped with the overall understanding. My tank is 36 inches deep and I want my corals to be super happy and have the light they need..do I need actinics?
<A true actinic (420nm) would offer some benefit but is not absolutely necessary if using high Kelvin temperature metal halide lamps.>
I am assuming I do, but don't know what would be best for the corals (SPS and LPS). I was using 2 96w vhos as actinic (Sunpaq retrofits) but the ballast stopped working and now it appears that CurrentUSA does not make that ballast anymore. I have T8 fixtures (2 - 48 inch) in the canopy as well, that I could hook up with a standard ballast. Is this a good option in your opinion?
<As above, for color pop they would be fine.>
If so, what kind of bulb would provide the spectrum I need? I would like the lights to come up before and after the MH and be beneficial to the growth in the tank as well.
<For the best PUR ratio, I would go with 15 or 20K metal halide lamps. 
Your 14K bulbs are still fine and I would not replace them if they are relatively new.  Corals respond best with wavelengths (PUR) between 400nm-550nm and 620nm-700nm.  In particular, between 465-485.  A Ushio 20K lamp will peak at 460nm and 550nm but the 550nm peak is 80% less in output.
 A Ushio 14K lamp peaks at 420nm but provides a higher output (20-50%) throughout the rest of the spectrum.  A wavelength of 450nm will produce the deepest penetration by far in sea water. Also disregard the Wiens Law formula I previously mentioned.  Is not very accurate when dealing with aquarium lamps that are designed to produce specific wavelengths.>
Thank you James :)
<You're welcome.  James (Salty Dog)>
Jess

Lighting 8/24/11
Hi Crew,
<Hi Sam>
I have a 24 gallon Aquapod with a glass top and T5 lighting of 96w (4 bulb fixture). I had 50/50 for a while and then changed to all daylight about a year ago. I can't tell if it helped the corals or not. I miss the actinic affect. I was thinking of getting an LED strip for the blue but I don't think a strip would show up against the 96w of daylight.
<It will be noticeable, more color pop. I'd stick with the daylight tubes and add the strip.>
So would it be ok to go back to 50/50.
Or maybe I could add 48w of T5 actinics with a new 2 bulb fixture.
My corals are LPS.
Thanks
<You're welcome. James (Salty Dog)>
Sam

Reef Lighting 12/6/10
Hey everyone how are we today?
<All is well, Matt>
I hope well. I got a question about bulb configuration on my 26 gallon bowfront. I have the Current
Sundial 4 24w T5 bulb light fixture. I briefly tell you what's in the tank and what bulbs I've had and thinking about getting and trying.
Top half the tank is few med size Acros and several small to large Montiporas and couple lps and lots of Zoas. Bottom half the tank is mainly few large lps and lots of Zoas and mushrooms. Ok in the past I
have used two different sets of bulbs, the first was one UVL 75/25 and dd
<?> <<D and D, UK distributor>>
Geismann "1100k"ish bulb ( forgot the exact name) and two 460nm blue acintics (actinics>. The second setup was that same dd Geismann bulb and an ATI Aquablue (1400k) and two UVL super acintics (420 nm). And now I was thinking of going with one 6500k and one super acintic <actinic> and two blue
460nm acintics <actinics>. So my question is, and sorry for dragging it out, is would the bulb config<uration> I'm considering be enough light or should I stay with two daylight bulbs like in the past? Thanks for your time!
<To make the most out of your available photosynthetic energy, I would use no more than one actinic
tube with the other three being in the 10-12K range. Four UVL Aquasun tubes will provide a nice looking display as well as providing a good nanometer range of useful light for your corals. James (Salty Dog)>
Matt

actinic question (how much is to much) 11/7/10
Ok so this might be a silly question, but how much is to much actinic light?
<Mmm, not really such an issue as is "to what ends can/should one employ such lighting?". There is more than sufficient spectra in this wavelength produced by other lights/lighting formats. Actinic is largely non-functional... i.e., it's principally for looks>
I am a huge fan of your site and you guys have helped me so much in the past, but I have search high and low for this answer and have not found a definite answer. I have a 40 breeder with star polyps, some fish, mushrooms, long tentacle anemones, carpet anemones, and live rock. All water parameters are fine, but I'm not sure if I am over doing it with my actinic lighting. Will it hurt my livestock if I leave my actinic on 24hrs a day?
<Mmm, not much; but then again, not of any real use to leave on continuously either>
I have all other lighting on a 10hr timer. I'm sorry I forgot to mention I run 2 t5 10k/ 2 460nm actinic during the day for 10hrs. The timer switches off the t5 and one actinic then switches on the lunar led's and other actinic light after. So you can say that I have actinic lights running for 24hrs. I only just started this cycle with the actinics but I don't want to harm anything in my tank. Do you think this is a bad idea?
<Yes... wasteful of energy and lamp, fixture life>
Can I keep this cycle? My girlfriend really likes the color. However she will have to just deal if it comes to hurting my fish. :-)
<I'd leave on a few extra hours, but not all night myself>
Thanks again you guys are the best. I seriously mean it. Shaun
<Welcome! Bob Fenner>

New Setup, Lighting... T5 lamp sel.  4/20/10
Hi,
<Hello>
I am thinking about buying the Sunlight Supply Tek Light T5 fixture (48"; 8x54W) for my 150G mixed reef tank and would like your advise on bulb selection. UV Light offers the following bulbs:
- super actinic
- aqua sun (10,000K)
- actinic white (12,000K; 50/50)
- aqua blue (14,000; 75/25)
The fixture has two switches and allows to turn on/off four bulbs at the same time. Could you please recommend the best combination of the light bulbs? Do I need to use Super Actinic bulbs at all? Can I replace them with Aqua Blue's? On one hand I don't
<You do not need the Super Actinics.>
I am thinking about the following combination:
- 2 aqua blue 14,000K
- 2 actinic white 12,000K
- 4 aqua sun 10,000
<Sounds good to me.>
Thank you for your help,
John
<Welcome>
<Chris> 

T5 bulb manufacturers and combination of bulbs  4/1/10
I am planning on changing both the bulbs, and combination of bulbs in my Nova Extreme fixture (8 54 W bulbs-4 10,000 K daylight, and 4 460 actinics.
There are several companies that produce these bulbs. I would greatly appreciate any suggestions as to which brands, and which combination of lights to use in this fixture.
Recently, I read here that actinic light's in themselves are not necessary, strictly aesthetic.
<Pretty much so with a good daylight bulb.>
The light produced by actinic bulbs is also produced in daylight bulbs. The blue light is nice aesthetically, but a combination of 50/50 is not the greatest for growing many hard corals that I would like to grow in my 120 gallon reef. Please correct me if I am wrong (I know you will).
<You are correct, but the fixture you have is powerful. Running a few actinics will not hurt your growth.>
Geissmann has a bulb called the PowerChrome Actinic + T5 lamp that looks appealing.
<My favorite T5 actinic.>
Aqua Medic also has a bulb called Ocean White which is a 10,000 K bulb as well.
<Also my fave for daylights.>
As you know, there are countless manufacturers out there, which are the best.
<You got them for my money.>
Also, what combination of bulbs would be best for general reef keeping? I know that is a very vague question, but am I am least on the right track in thinking that I should replace some of those 4 actinic bulbs with more white light?
<With this fixture I would personally run 3 actinics. Four at the most, two at the least or the tank will be too yellow
for the taste of many out there.>
Thank you as always,
Jeffrey Castaldo
<Welcome, Scott V.>

Actinic PCs'¦Do I Need Them? -- 03/30/10
Hello,
<<Hiya John>>
I have the Coralife retro fit kit over my 125 gallon tank. It has 3 150 watt HQI double ended metal halides and 4 96 watt PC actinic. I just replaced the halides with Ushio 10ks.
<<And a nice upgrade over the stock bulbs that came with the unit>>
I know the PCs are old, but do not know how old because I got it used. I think they are 1 to 2 years old.
<<Mmm, okay'¦and as PCs go, these are indeed 'old'>>
I thought I read someone on WetWebMedia saying that the PC actinic lights would not do much in a setup like mine.
<<That depends on the context of the statement I suppose. As far as useful light energy goes, no, the PCs are not needed/do not much as the metal halides supply the required intense light energy (even in the blue/actinic range) for your photosynthetic organisms'¦as far as aesthetics go, if this is your thing then yes, the PCs can add some extra 'glow' to the setup>>
Not really sure if I understood correctly. Should I not bother replacing the PC actinic lights at all or maybe replace them with 10k or higher?
<<Up to you, really'¦ If you like the look of the tank 'without' the Actinic PCs then replace these with a 10K bulb>>
If I should get actinic lights, what kind?
<<I don't feel it matters'¦ Get what suits your eye and your budget>>
I see they have 460nm, 420nm, and dual 420nm/460nm. At least give me the pros and cons or a suggestion.
<<I suggest you not sweat it and just 'pick one' based on the way it looks/what appeals to you>>
I don't really know the difference. I have mostly LPSs in my tank a brain, elegance, bubble, trumpet, candy cane, softies, and a few SPS frags. On a sort of unrelated note when my halide bulbs went bad the lights started tripping my CGFI, but that stopped after I replaced the bulbs. Is that normal or possible?
<<Normal'¦don't know'¦but have not ever experienced this. Possible'¦I reckon'¦arcing of the bulb/voltage fluctuations may well have tripped the ground fault, especially if it is old (GFCIs also go bad/require periodic replacement)>>
I got the lights used about 6 months ago, so I think they were really old and really bad.
<<Quite possibly so>>
Thanks,
John
<<Happy to share'¦ EricR>>

Re: Actinic PCs'¦Do I Need Them? -- 03/30/10
Hello again,
<<Hey John>>
Yes, I was wondering if the PC actinics had any added photosynthetic benefit or if they were purely aesthetics.
<<In a setup such as yours, this last is pretty much the case>>
If they are just for looks then I am fine with the way they look now and would not bother replacing them.
<<Indeed'¦I let my T5 Actinics burn till they 'won't burn no more.' These are merely used for day/night transitions and for the small amount of phosphorescence they produce. The real 'punch' of my lighting system, like yours, comes from 10K metal halides>>
If replacing them would help my corals then I would spend the money to get new ones. So the PCs do not provide any light energy at all or is so little that it is not worth it?
<<The Actinic PCs do produce light energy, it is just that this short-wave light is supplied in plenty by the metal halides, and alone is not nearly as important as supplying good full-spectrum lighting to your tank (i.e. -- your 10K metal halides)>>
I thought I had about 800 watts of light before, but if the PCs are useless PAR wise then I am really down to 450 watts right?
<<Indeed'¦if counting watts and measuring/determining lighting requirements in this way (which is by no means 'cut and dry' as the type of light source, reflectors, tank dimensions, photosynthetic requirements of the organisms kept, et al, must also be considered) then I would not include the PCs>>
That is what I read before then, but I just found it shocking because some people get PCs only for their tank.
<<They do, yes'¦but they also don't generally use ALL Actinic bulbs and they learn to understand and work within the limitations of this type lighting>>
To clarify, PC type of light just isn't intense enough to do much PAR wise or is it actinics don't do much PAR wise and are for looks?
<<More of the latter>>
I could get 20k PCs if they would help my corals, but again if the PCs are not intense enough to matter for PAR then I will just stick with the old actinics until they burn out because they look fine as far as aesthetics go.
<<With the 10K metal halide lighting you have, I would leave the PCs as they are>>
Thanks,
John
<<Always welcome'¦ EricR>>

Re Lighting Question/Reef Lighting/Selection 12/17/09
Thank you very much. I am very impressed with the quickness of your replies. I will do what you recommended.
<Do keep in mind that this is my opinion, other peoples opinions can be different. I just feel that the 10K lamps are a better light source for SPS and clams, and do not waste intensity. I have switched over to Ice Cap 10K lamps some time ago and I did see an improvement in my SPS growth. You may be interested to read part of an email I received from Steven Pro, VP of sales at Ice Cap. "Although I will say that the amount of blue in a 10,000 K lamp is something that is not universally well understood. When looking at the spectral chart of our 10,000 K versus 14,000 K versus 20,000 K lamps (or that of other respected companies such as Ushio for example), there is
no more blue in the 20,000 K lamps. In fact, all three color temperatures have the exact same amount of blue in them. The way manufacturers get a lamp that appears more blue is not to add more blue to the 20,000 K lamp, but to remove the green, red, and yellow from the lamp." With that said, it is the green, red, and yellow that our shallow water corals and clams benefit more by than the blue.>
Thanks,
<You're welcome. James (Salty Dog)>
Ryan Lundstrom

Re Coralline Algae Issues And Substrate/corlinepropfaqs 12/7/09
Good day James,
<Blesson>
Thanks for making me realise how dumb I have been by adding buffering solutions twice!
<Reading would have prevented this.>
The crushed coral is kinda really big in terms of particle size. Actually more like they &#39;re chunks not grains! Average grain size would be around one to half a centimeter! No way can I siphon it without getting the particles caught in the siphon tube. And guess I will change to the fine sand as you said.
<Did not tell you to change, but said "Crushed coral sand will aid in maintaining dKH levels and will be much better than the mixture you have.">
One portion at a time. And will the 14000k MH bulb produce enough in the blue spectrum for the coralline and white for the coral?
<Yes, and keep in mind that photosynthetic efficiency peaks at around 430 nanometers which is very close to the major spectral output of a standard 'actinic' bulb. This wavelength is always present in lamps designed for reefkeeping. The lower Kelvin temperature (6500-10000) lamps do not appear blue because the intensity of the other colors in the spectrum is much higher. As we go up in Kelvin temperature, the proportion of blue gets higher while the reds, yellows, etc. are proportionately lowered. The light loving invertebrates we generally keep seem to do better with Kelvin temperatures between 6500-14000. The Ushio link provided here will show spectral graphs of what I am saying. http://www.ushio.com/products/petcare/aqualite.htm >
Or I could manage to get hold of a 20000k bulb if it helps.
<I would not, 14K would be a good lamp for your needs, 20K lamps are more suited for deeper water light loving invertebrates. Clams especially, will not do well under this lighting.>
And yes I will get the magnesium solution too. Didn't know it could play such a vital role in the prop of Coralline.
<In most calcium loving invertebrates. Magnesium is one of the major elements of sea water.>
I didn't even know there is a test kit for measuring it either!
<Oh yes, several kits are available.>
Just shows how less I know in this hobby.
<That is why more reading and less writing is necessary.>
And regarding the mention of Actinics to grow coralline and other than that just for aesthetic purpose, think I read it in the Actinic lamp faqs section.
And nope not confusing it with the Lunar or L.E.D.s. The tube I spoke about is essentially a normal 20 watt fluorescent tube 2 ft long. Think it's coated blue or something. Read the cover and stuff but nothing mentioned about the wave length or it being an actinic.
<The term "actinic" was a poor choice to label these lamps. Photographers used this term in that lamps that were darkroom safe were commonly called actinic lamps because their spectral output had no detrimental effect on photo paper, it allowed them to see what they were doing in the darkroom without ruining photo papers.>
Thanks again James. Read the crew member faqs, you guys have got a great thing going on. A real wonderful service rendered to this hobby. Thanks again.
<You're welcome, and less writing, more reading. You will find most of your questions answered by Googling our site. James (Salty Dog)>
Blesson

Re Coralline Algae Issues And Substrate/corlinepropfaqs 12/7/09
Hi James,
<Hello Blesson>
Found the faq I was citing. Its called actinic vs blue pc lighting. Replied by wetwebber ScottV I think . . . Pls do clarify . . .
<If you are referring to "The actinic and blue bulb mentioned will do little or nothing towards sustaining photosynthetic organisms", then I personally do not agree with this, as this spectrum/wavelength is present in all lamps designed for reef systems. We just do not see it in lower Kelvin temperature lamps because the other colors of the spectrum are much higher in intensity and tend to mask the blue. I'm thinking Scott V. may be alluding to using just this type of lamp. James (Salty Dog)>

Re Coralline Algae Issues And Substrate/corlinepropfaqs 12/7/09
Hello James,
<Blesson>
Yup I understand. Will definitely read more instead of sending so many mails.
<Yes, and will provide more detail than I have the time for.>
Thanks a lot for all the help.
<You're welcome. James (Salty Dog)>
Blesson.

Blue Lights:)/Reef Lighting 10/23/09
<Hello Jean>
If there's anywhere on the web that has the expert advice of so many combined years of experience, I know it's most easily found here. Thank you all for being so many peoples sounding board on such a gamut of issues.
<Thank you for the kind words, Jean.>
My issue, (at this very minute) happens to be on actinic lighting. Yes, I'm quite aware of the controversy of the issue of lighting and I've given myself more than one headache reading study after study on par/Pur; lumens/mcd; efficiency, heat transfer... the list goes on. I've just read some interesting facts about actinic lights on some forums that made me think... why can't I just use blue lights? The definition of actinic really only seems to come down to the 'blue' spectrum of visible light, and maybe a little that's not visible.
<The term actinic actually refers to that portion of light that effects chemical changes. The term was commonly used in early photography to distinguish light that would expose monochrome films from light that would not. Photographers would call their darkroom red or amber lights 'actinic safe'.>
The '03' prefix that so many like to add to their lights seems to refer to the model number of the original actinic bulb that Phillips produced. No where can I find a good answer on which range is better for photosymbiotic animals, be it 420nm, 460nm or what have you.
<You likely won't. Corals flourish between 400nm-700nm (not macro algae), so providing lighting in this range would be your goal.>
So, really for the sake of argument and I realize I'm being facetious here... why can't I just use blue lights? Stripping the thought process of any manner of strength, watts, type, distance, I know those aspects all play a very key role in properly lighting a reef aquarium. Is there truly any reason a plain blue... Christmas light for all I care, doesn't put out at least some useful blue spectrum that zooxanthellae algae could use to facilitate photosynthesis? Why does it have to be '03 actinic' What am I missing? To cap this off, thanks for putting up with me! :)
<You actually could use 'blue' lights as long as they produced the intensity needed in the 400-700nm range. One thing to keep in mind is this; reputable lamp manufacturers such as Ice Cap, produce lamps for coral growth in three Kelvin temperatures, 10K, 14K, and 20K. Interestingly enough, they all have very close to the same amount of 'blue' in them (recent conversation with Steven Pro/Ice Cap). The difference in the higher Kelvin lamps is that there are less phosphors used that emit the red, yellow, and green light, and that is why they appear bluer. There are lamp manufacturers that may add more blue in their higher Kelvin temperature lamps, in some cases by as much as three times the amount (Ushio), but there is always some reduction of the red, yellow, and green. This is the reason why some manufacturers 10K lamps will differ in appearance from other manufacturers 10K lamps. See Ushio spectral chart here,
http://www.manhattanreefs.com/lighting2/spectraldata-line-2.php
Hoping this helps you out. James (Salty Dog)>
Jéan Dodes 

Two Questions (Reef Compatibility/Lighting Suitability) -- 07/13/09
Hi guys,
<<Daniel>>
I have two different problems.
First: Mystery Wrasse (Pseudocheilinus ocellatus). Is it going to work in reef tank?
<<Depends'¦but generally, yes, they do fine with most other 'reef' inhabitants. Though like most any other wrasse, they can pose a threat to small crustaceans>>
I was about to buy that fish but seller warned me that it will go eventually after my shrimps (2 medium cleaner and blood shrimp and couple wurdemanni).
<<If the shrimp are very small, and the wrasse is mature/large'¦this is a possibility>>
So I backed off, but still can't get that fish out of head, beautiful
<<Ah, yes indeed>>
and very good priced. Any suggestions? Tank is 100gal, not overcrowded.
<<It is a gamble'¦and 'you' have to decide if it is 'worth it.' Personally, I would give the wrasse a go>>
Second: I have PC lightning over my 100g reef, 4x96watts. Two daylight and two actinic bulbs. Because it's soon time to change bulbs I was thinking about making it more blue, so it would be 2xactinic and 2x50/50bulbs. I know corals need more daylight, but since that tank is shallow (20inch), and I keep only LPSs (I can put them higher) and Zoas it might work. Or not? What do you guys think about more blue light in this case?
<<Well, I've seen some pretty 'blue' tanks before'¦ I think this is a bit much in this case but, if you are keeping deep/deeper water species it will probably be fine. At any rate'¦you can always keep an eye on your livestock and switch to more 'daylight spectrum' bulbs if anything looks to be suffering under all that blue light>>
Regards,
Daniel P
<<Cheers, EricR>>

Changing Actinic Bulbs 6/30/09
Hello,
I have tried to find any info if the spectrum changes in actinic fluorescent lamps. I've had the same two 72" actinic lamps in my tank for about a year now and they seem fine.
<I can't find anything specifically on the spectral changes of actinic bulbs, but it is well known that bulb spectrums do slowly shift over time, and can not stop emitting beneficial light, but even start emitting light
that encourages algae growth. Actinic bulbs likely experience a shift in spectrum as well, but I can not find any literature regarding the shift in actinic bulbs.>
I was wondering if they should be changed out like MH lamps should be - or alternately if they are good until they burn out?
<Actually, the bulbs almost undoubtedly have lost much of their intensity. But that intensity loss happens so slowly that it is hard to visualize.
For aesthetic reasons I would suggest changing the actinic bulbs. I think you will find there is a bigger difference than you expect.>
Thanks for the help!
Cassidy
<Your welcome,
Josh Solomon.>

Lionfish Lighting Actinics Only? 4/16/2009
<Hi>
I just had a quick question about keeping a Volitans Lionfish.
<You've come to the right place..
Would it be harmful to the eyesight of a lion if I just used actinic lighting only?
<No, but the Lion isn't going to look as nice only under actinics either.>
Also would having only actinic lighting encourage algae growth?
<No>
The amount of lighting would be in the range of 2 watts per gallon. Thanks for your time and advise.
<Personally, I would not do this. A low light tank is fine, but reef fish do need some "real" light. Something along the lines of 1/3 regular and 2/3 actinic would be much better.>
<Mike>

Actinic VHO bulbs 3/18/09
Hello everyone.
<Hello Jon.>
I have had a reef tank up close to 20 yrs and have a question regarding 110wt VHO actinic bulbs. I used to always get Hamilton but have been trying URI and went back to try Hamilton again because URI actinic white was pink to me I have noticed that both the companies actinic bulbs are now more blue then they used to be. (At least Hamilton's were). I remember having more of a purple tint to them.
Am I crazy or what bulb would give me that nice purple back?
<Not that I am aware of, but I find it hard to believe the manufacturing has not changed at all through the years....this could effect the look of the bulb.
If you are not liking the looks of these (the URIs are my personal faves BTW), give these a shot:
http://www.customaquatic.com/estore/control/product/~product=LT-PC48VHO-B
I tried them a while back and found them too purple for my taste...may just fit your bill.>
The Hamilton's I have are Super Actinic Blue and URI's are Super Actinic.
Are actinic 03 different?
<Actinic 03 is a reference of a spectral peak at 420 nm. Different actinic 03s can look very, very different.>
Thanks for any help.
Jon Olson in California
<Welcome, Scott V.>

Actinics and 10000K CF vs. Coralline and Hair Algae 2/12/09Hola WWM Crew. <Hi John> Thanks again for all you do. <You're welcome.> Now that we got the poetry out of the way, I would like to ask a variant on the old "should I take out my actinics and replace them with high K CF bulbs" question. I have a 75 gallon with good parameters (not essential here) . Some nitrogen and phosphate evidenced by a little hair algae but I am getting this under control with diligence. I have a 48" Coralife Aqualight Pro 2X150HQI 2X96CF actinic. It is getting to be time to change the actinics. I don't really like the actinic color that much, and the coral doesn't care. I was thinking about putting in 10000K CF bulbs. Two questions: Will the 192 watts of CF 10000K provide a material marginal benefit to my SPS relative to the 300 watts of HQI? <Will help some, but I wouldn't base my decision on it.> Will the move to 10000K hinder my coralline more than it hinders my GHA or do GHA and Coralline like the same spectrum? <Coralline seems to do better under actinic.> I was thinking about 6000-7000 but really don't like the color. <The lower Kelvin temps are more prone to growing hair algae than 10K and higher, but excess nutrients are going to be the main cause of nuisance algae in your tank. You didn't state what the Kelvin temperature is on your HQI lamps, but I do know the fixture comes with 10K lamps. So, if you haven't yet replaced them, I'll assume that is what you are using now. If plating coralline is desired, I'd stick with one actinic and replace the other CF lamp with a 10K. This will reduce the blue effect you are not fond of and should give you a nice overall color balance.> Thanks <You're welcome. James (Salty Dog)> John / Fishnut

Re: Adequate Reef Lighting? Actinic f' ~ 01/06/09 Do the actinic bulbs count toward the total watts of light being delivered to the tank or is it just the whites?? <<The basis of the formula is ANY wattage? But? A 10,000K bulb is going to provide more useful output than an Actinic bulb of the same wattage? And points out yet another inherent flaw to using this woefully poor *formula* for determining the effectiveness of your lighting>> Thanks again, Peter <<Regards, EricR>>

Actinic Only...   7-14-08 Hello, <How goes it? Mike here today> Thank you for your service. <You're welcome> I have a "stupid" question. I have a 120 gal. fish only tank. For now I have a puffer, two clown gobies, a starry blenny, and a scooter blenny. I was wondering about the possible health effects to these fish by using actinic only. I don't care about coral growth and coralline growth. This is a fish only tank. I have a refugium below the cabinet doing very well with 40w aquarium spectrum bulbs. After employing the actinic only for three weeks, my algae problem has cleared up and the fish seem perfectly fine. Am I doing something wrong by doing this? <It won't harm the fish, so if that's what you want to do, go ahead. It's not the best way to eliminate nuisance algae, but I suppose it will (mostly) work. Your fish would be better off if you worked to eliminate the excess organics in the water, rather than just denied the nuisance algae it's necessary light> Thanks for your help. <Anytime> Douglas <M. Maddox>

Reef Lighting/Got The Blues For Blue 3/24/08 Hello, <Hi> I currently received a new lighting system for my birthday. <Why can't I have birthdays like that.> It's an Outer Orbit fixture with 2 - 150W 10K halides with 2 - 420nm T5 and 2 - 460nm T5. The tank is a 65 gallon reef tank 36 x 18 x 24. The tank used to be powered by 2 - 150W 20K halides, but want more sps and possibly clams so changed to the 10K with actinic supplement (Better PAR value). After firing up the system I found that the blues in my tank really dropped out. <Yes, would be a big change from 20 to 10K, but the actinics should give you plenty of blue.> I feel as if the actinic bulbs that came with the system aren't up to snuff, so I feel an upgrade is already needed with these bulbs. My main question is what kind of T5 actinic bulb will give me the most blue in my tank, and what brand do you think is the best? <I'm thinking nothing is wrong with your lamps, is an acclimation period you will have to go through. I believe in time they will look much bluer than they do now. Is what you are accustomed to seeing.> I was contemplating between Giesemann, and I heard that ATI makes good T5 lamps. I was thinking maybe getting 2 Phoenix 14K bulbs for the system as well, I read great reviews for these bulbs. If I do go with the 14K's, will the PAR drop be significant, or will it be fine? <With the HQI's, no worries here.> Coral growth with the SPS and Bubble Tip anemone was decent under the old 20K's. Note: all halides are HQI. I just want to bring the blues back, in a good way. <If you must have the blues, I'd leave the actinics be and go with a couple of 14 or 15K HQI lamps. Myself, I use 14K MH with nothing else and I like the look, not much blue but I'm not a blues fan.> Thanks <You're welcome. James (Salty Dog)>

Actinic Lighting And Eye Damage? 2/9/08 Heya Crew! <Hiya Grant> I keep an actinic light on for a few hours after the regular lights turn off. Purely for the aesthetic night-time effect of the glowing corals. I understand that "black lights" are damaging to human eyes due to the UV light they put out, and was curious as to whether or not actinics have the same or similar damaging effect... not so much for my own health but for my Undulated Moray (Gymnothorax undulatus) which, being nocturnal, is primarily out and about when only the actinic light is on (and then of course all night when they're off). I couldn't find anything about it in the faq's and I do apologize if it has already been asked and I over looked it. Thank you all for your time and knowledge, it really makes things so much easier and more enjoyable for us amateurs :-) <No threat to eye damage here, just lighting in the 460nm range. James (Salty Dog)> -Grant-

Lunar Lights and Coralline Algae ? 02/04/08 Hi, <<Hello>> I am trying to pick the proper light fixture to help grow coralline algae. <<Hmm?best to concentrate on providing proper lighting for your corals needs (assuming you have these). If your water chemistry is as it should be, the Coralline will come>> Both fixtures come with 1 daylight lamp and 1 actinic. But one fixture has a white lunar light and the other has a blue lunar light. Will the color of the lunar light make a difference? <<No, the lunar light will have no impact?pick the one that is more aesthetically pleasing to ?you?>> I don't want to overdo the blue. <<You may well be, though not as a result of the lunar light color you choose. But without more info re these lighting fixtures and your tank and its inhabitants, I?m unable to comment. But then, maybe your wish was to only inquire about the lunar lights [grin]>> Thanks, Danielle <<Happy to share. EricR>>

Lighting, reef, actinics    02/03/2008 Good day crew, <<Hey there. Andrew here>> It is that time of year to change bulbs. I was wondering if you could please give me some advice on my change out. I have a 75g reef with SPS, LPS, rose anemone and clams. I currently use two 150 M.H. with two 96 watt actinic 03 bulbs. I'm looking to go with 14k bulbs, but I was wondering about the actinic. Should I keep them the same, or use 10k, a mix or ??? <<Actinics tubes, themselves, are really only for your viewing benefit and I would leave them as they are. Moving to the 14k bulbs on the halides will give you a nice balance color in the tank with existing actinics you have for supplement>> As always, I love your site, and have gained a tremendous amount of knowledge from it. Be safe. Thanks kindly, Mark <<Thanks for the questions. A Nixon>>

Actinic vs. Blue PC Bulbs 1/31/08 You guys were great last time, so I figured I would try you again? <Hello Nick, why not, huh?> I have power compacts and I have done research and I have found that coralline algae and some corals/anemones prefer bluer light, mainly the coralline algae though. I am going to replace one of my daylight bulbs w/ an actinic blue. <OK, what else is in the tank that may be affected by this?> I have two Coralife 65w bulbs one day and one blue (actually purple) and two SunPaq 65w 50/50's currently. My question is: The actinic blue for the Coralife looks purple and the SunPaqs are actually blue! Does Coralife have a better bulb? <Not necessarily.> The color temp for the replacement SunPaqs is like 7100k but I can't find any info on what the color temp for the Coralife bulbs are, they sure look different (much more purple). <The SunPaq you are referring to is likely a 50/50 ?blue? 7100K (460nm) bulb and actinic (420nm), while the Coralife sounds like a 100% actinic bulb, yielding a very different look.> I have always heard that the higher color temps are better, but I know that color temp and intensity are different. <Higher K bulbs are better for what most want for aesthetics nowadays. Corals do better under the 10000K or even 6500K offerings out there. They offer more intensity in the usable spectra involved. The actinic and blue bulb mentioned will do little or nothing towards sustaining photosynthetic organisms.> The Coralife bulbs are almost twice the price of the regular SunPaq actinic's maybe suggesting that they are better (more specifically formulated)? <No, Current USA has a comparable actinic bulb, as well as other companies.> The SunPaqs mention that they are the optimum spectrum for reefs too? <Possibly, depending on spectrum of the bulb. No one manufacturer can claim that theirs is the optimum spectrum while offering multiple spectra of bulbs.> Thanks for your time...it is most appreciated by a novice like me. Nick <Welcome, Scott V.>

Re: Actinic vs. Blue PC Bulbs 2/2/08 I have a Kenya tree coral, a long tentacle anemone, several types of polyps, feather dusters etc.... From what you are saying? I gather it is better to have a 50/50 spectrum of light to best suit everything. I am more like 65/35 blue/white after changing one of my lights to all blue instead of 50/50. Most lab studies I have seen suggest that coralline does better under a slightly bluer light? This makes sense to me, because one of the things that I have noticed is that algae growth can really stunt coralline growth by covering it <Not with proper nutrient control.> and basically smothering it also it seems to be flourishing more in the shadowy areas of the tank (many others on the web, echo these sentiments). If what you are saying about 10,000k daylight is true? (which I believe it is, I have two 6500k daylight compact fluorescent floods (home depot $7.00 http://www.melevsreef.com/fuge_bulb.html on my refugium and the Caulerpa is out of control). <Good.> Basically, I know that whiter light is better for standard photosynthesis (plants especially), but many corals inverts exist 10,15,20ft down, where very little low frequency white light exists. <Photosynthesis still occurs the same way, same usable wavelengths of light even though there is less of it, giving a bluer appearance.> Mainly the higher frequency blue light makes it to these depths. So isn't that a good argument for having a slightly bluer spectrum rather than 50/50. <Hmmm, no this will still be less usable light, it just provides a look.> My tree coral has spread out more since I put the bluer light on the tank <It is increasing its surface area trying to receive more light and it can only do so to a point.> + I always see people who keep coral frags and sell them, keeping them under bluer light. <Some do, but not under the spectra we are talking about as a sole means if lighting them. Many serious fraggers will grow corals under the 10000K or even 6500K lights. Some will then sell them under 14000K or bluer bulbs just for the look it gives the frags.> I replaced one of my 50/50 SunPaqs w/ a SunPaq blue, not the purplish violet. Now I am slightly bluer, already it seems I have less algae growth and better coralline growth. <If it works for you, Great. Do keep an eye on the anemone, it is the most light hungry of the livestock you list.> All of the corals seem to be doing just fine, if not better. I do agree, many species of hard corals exist in only a few feet of water and get allot of white light and they thrive under it. But I also think that since many soft corals survive at higher depths that, somehow they have grown accustomed to the spectrum there and too much white light may be too intense. <It is possible have too much light for any species, regardless of spectrum. With the lower spectrum bulbs it will take less to satisfy their needs.> But I could be wrong! maybe the only reason soft corals do not exist at such shallow depths is because they are more delicate to thrashing waves and high current that could destroy there more delicate bodies. <Has something to do with it.> If that was the case then they should not have evolved to live at higher depths because of the light conditions and mainly due to the water conditions. But that begs the question? After millions of years of evolution at higher depths, you would think they would have evolved to utilize the bluer light better. <Nope, they still don?t use the bluer spectrum the same as the lower (photosynthetic) end.> I believe I am answering my own questions....I think the truth is that there is no easy explanation...it would make sense that different organisms evolved to utilize the light better for the depth in which they exist? <Yes, the amount there of.> Meaning that there is no straight answer, it just depends on what you are keeping! <Exactly.> If whiter 10,000k is better, then you would think most hobbyists would use only those bulbs! <Aesthetics count too, hence the higher and higher Kelvin bulbs coming out all the time. Look at what is still considered the king of coral growth, the Iwasaki 6500K bulb! Too very yellow for my taste, but it will grow frags out relatively fast.> Are they that concerned about aesthetics?... <A factor, yes.> besides blue light has to have a good purpose for the reasons I explained above ie: depth that creatures exist at etc.....? <All of the above can also be accomplished with less or no light too.> Nick <Check out the links below, there is much information, some based on science and some not, out there. Thanks for writing, Scott V.> http://www.wetwebmedia.com/marlgtganthony.htm http://www.reeflightinginfo.arvixe.com/

Frogspawn stalk question... hlth. mostly, and a "blue" light LED f'  ? 1/26/08 Hi there, I have a seemingly healthy and happy frogspawn that has grown from three heads to seven in about 5 months (he loves mysis shrimp). <Mmm, needs more than this, nutrition and water quality supplement-wise> I have the 5 inch stalk stuffed into a hole in one of my rocks to anchor it. well.. something is eating away at the stalk and it is looking pretty weak at this point so I have two questions. 1) what do I do once it breaks? <Re-orient, place it> and 2) what is eating the stalk? <Perhaps nothing. Have you observed a predator?> I have two ridiculously large black urchins, <Mmm, could be poking it> 1 scooter blenny, 1 fox face (he came after this started) 4 green chromis, 1 mandarin, two tank bred percula clowns, and something that is 1/2 pink 1/2 yellow his make eludes me at the moment. I add calcium occasionally <How and why?> and an all in one nutrient supplement once every week or two. <... of what constituency, and how do you test for?> I'll admit that I almost never change my water but I seem to have a high evaporation rate and add a gallon of distilled water per day( not sure if that is good or not but it certainly stopped my algae issues). <And your stony coral health evidently> I used to test my water constantly but now I do it rarely because all looks well. <... can be deceiving. I "measure" such events in life by "results"> I do have a bristle worm problem that I am trying to solve. <Small possibility that these polychaetes might be involved as well...> Thanks in advance. <Ummm, well... there could be "something" chewing et al. here... but could just as well be an anomaly of water quality and/or nutrition at play... making the skeleton of the Euphylliid "soft"... Need more/real data to assess better... Or you might read: http://wetwebmedia.com/carydisfaqs.htm and the linked files above...> P.S. would you consider the PowerBrite 460 led blue light a moon light? <Sure> I just bought it today and the salesmen said it was a moonlight but it says its for growth?? <Mmm, blue? What wavelengths? See WWM re... will not likely boost growth, or photosynthesis period. Bob Fenner>

T5/Power Compact Actinics 1/18/08 Hello, First off, I have a 65 gallon...36x18x24....and I'm upgrading to (2) 250W HQI's 10K, and I want to know what the main difference in T5 and PC actinics is. I want to have clams and SPS in the future. I had clams before with my current system, (2) 150W HQI 20K, but they died. Don't think the light made it all the way to them, bummer. <The higher wattage and better spectrum will definitely help> Have some LPS, SPS and polyps now, all doing well. With the 250W's I can transfer over to a SPS tank easier and clams would live on the bottom. <Yes.> Would T5 actinic or PC actinic be a better fit with this system or is it a personal aesthetic choice. <Kind of a personal preference.> Would (4) T5 actinics be overkill for this tank with the halides? <For my taste, yes. For many others, no. It is a matter of preference.> Or should I go with (2) Power compact actinics? I'm in a decision bind. Kind of want to make this lighting change the last one, help me make up my mind. Thanks for all the great advice! <Honestly it is kind of six in one, half a dozen in the other. I prefer the T5?s, mainly because of the ability to run a lower wattage (while still running the length of the tank) and flexibility therein. You can run one for 39W to four for 156W or any combination in between. There are also more bulb choices coming out in the T5 format as of late. Hope this helps you decide, Scott V.>

Actinic Light During Night Cycle? 11/29/07 Hi Crew, <<Howdy John>> I think this might be a new one for you. <<Oh?>> I've been pouring the FAQs for a couple days and cannot find this specific topic. <<Okay>> I have a 37gal FOWLR with about 50lbs of LR and a few low light coral Frags. (2 mushroom colonies and a Frogspawn). For fish, I have a False Percula, Royal Gramma, Blue Reef Chromis and a Banggai Cardinal. <<Neat>> I currently run 2 30" Coralife T5 AquaLights. These are the ones with T5 NO lights. They came with an 18w 10000k and an 18w actinic in each. In one fixture, I swapped the actinic for another 10000k. This gives me a nice clean white light with a small tint of blue that I like. <<Yes indeed... And although ?moderate? in its lighting requirements, the Frogspawn likely appreciates this added bit of ?white? light>> Anyway, I would like to add some nighttime lighting, mainly for aesthetics in the room. <<I see>> I have tried a couple of the different LED devices that are available, but none of them put out enough light to make anything visible in that tank at night. <<Really? I would think these to be quite adequate for a tank such as yours>> I think these things are just someone's idea of how to sell another device to us hobbyists, as I can find no practical use for them. <<Perhaps... Many hobbyists could get by with a simple low-wattage incandescent bulb for this purpose...but hey, when it comes to the chance for buying another gizmo.........>> I was thinking of trying something else. I have an old double fluorescent strip light from my early days that takes 2 24" NO bulbs. I have experimented with running one 20w NO actinic at night. The fixture is set on top of the T5 fixtures in a way that only allows about 30% of the actual light to reach the tank. <<Ah...good>> This gives me a pleasant amount of blue light, while still maintaining an after-dark look to the tank. <<Sounds nice>> My concern is, if I have this light running opposite my main lights, I will essentially be lighting the tank around the clock. <<Not really...at least, not in the same manner/with the same result>> Do you think this could have any negative effect on my rock, corals or fish? <<If too bright, yes...but if the light intensity/brightness is such that the organisms in the tank recognize the change from day to night and are able to rest it should be fine. Simply observe to see if the tank still settles down and that the fishes seek out their nighttime hiding/resting places with the Actinic ?nightlight? on. And since this ?fishy nightlight? is primarily for your pleasure, consider putting it on a timer to shut it off once you leave the room/retire for the evening>> Thanks for all the great info over the past few years, <<A collective effort...we?re happy to assist>> John Arenz Big Lake, MN <<Eric Russell...Columbia, SC>>

Lighting Question... actinics  11/8/07 Hello, <Hello Tom> I have a quick question and did not find the answer on the site. I have a 4 year old 20 gallon reef. The first two years the tank was FOWLR. The question is: I am using a 24" Corallife Lunar light with a 65 watt 10000K and 65 watt Actinic. 130/20=6.5 watts per gallon. Would it be better to replace the Actinic with another 10000K bulb? I would like to add more "light loving coral" does the Actinic really do that much for my tank. <Cosmetic>Light schedule is as follows: 10am - 8pm Actinic and 12pm - 6pm 10000K. Thanks for your help and keep up the great work! -Tom <Thanks Tom. I would probably replace the bulb with a 50% 10k and 50% actinic bulb. The actinic is primarily cosmetic in this case, but that does count for something. This will give you more usable light without losing the look you are used to. The only drawback is losing your dusk/dawn phases, which you would lose anyhow going to two 10 k?s . The photoperiod will depend on what you are keeping and where it is in your tank, but I would increase the 10k period to 8-10 hours. Happy reefing, Scott V.>

Lighting Question?Best Color Combo? ? 11/01/07 Good Evening, <<Hello>> I have a question about lighting. <<Okay>> I am getting ready to change out the bulbs on my Corallife fixture. I currently have (2) 65W Actinic, and (2) 65W 10,000k compact fluorescent bulbs. <<I see>> I'm thinking about changing it up because I understand the Actinic lighting may not be that beneficial. <<It ?is? beneficial?but these short wavelengths are already present in suitable quantity in most all aquarium lighting with a color temperature above 5000K>> Which of the following configurations would you recommend: (2) 10,000K and (2) 50/50 or (2) 10,000K and (2) 6700K? My corals consist of Torch, Frogspawn, Xenia, Candy Cane, and Starburst. Thanks, Jackie <<Either choice will be fine. I suggest you make your choice based on your sense of aesthetics (likely the first configuration will be more pleasing to the ?human? eye). Regards, EricR>>

Another Reader?s Rebuttal To A Previous Query?Coral health. Too Much Actinic Lighting ? 09/21/07 I noticed that under this post in the actinic section Eric responded that this would be too much actinic and not enough useful light. <<I did, yes? And generally speaking, I believe most aquarists provide more light in the ?Actinic? spectrum than is necessary?sometimes even to the detriment of their livestock. Pretty much any bulb with a Kelvin rating of 6500K and up will contain plenty of this narrow, short-wave, light spectrum for corals? needs>> I would disagree if you look at the par numbers you will see that the Aqua blue and Blue Plus provide very large amounts of par. <<Mmm, yes?my argument is not PAR (Photosynthetically Active Radiation) but rather, useable ?spectrum??or the lack of it, with 100% Actinic bulbs. Most all corals benefit from more ?full-spectrum? lighting>> The ATI Blue Plus while looking like an actinic provides more par than some other manufacturer?s daylight bulb! Here is a reference: http://www.reefcentral.com/forums/showthread.php?s=&postid=8050994 <<PAR is a flat measurement across the visible spectrums of light?it indicates the ?amount? of light, but does not/can not indicate which individual spectrum of light or its measure of ?usefulness? to the corals>> I run 4x54 ATI AquaBlue/Blue Plus over a 75 gallon tank and have no issues with SPS corals including acropora (kept higher up). <<Many of the corals we strive keep are more adaptive than we often realize?and lighting is only but a part of the equation for success. Still, I suspect more light with a longer wave-length (6500K ? 10000K) would benefit your corals in the long term>> I love the site; it is an invaluable service to the hobby. <<Thank you?is rewarding to read. Regards, Eric Russell>>

Coral health. Too Much Actinic Lighting ? 07/10/07 Thanks for all the help over the past two years as I've gotten into the hobby. Your site is my go to site for advice. <<We?re glad we could be here>> I have a 165G tank with SPS on the top and LPS and softies in the middle and bottom. I run two Tunzes and a Wavebox for flow and 214 watts of T5 Aquablue and 214 watts of T5 Blue+ for lighting. <<From what I can find, the Aquablue bulbs are 60% Actinic and the Blue+ bulbs are 100% Actinic... Not nearly enough useful spectrum/way too much Actinic lighting here>> All the bulbs have individual Tek reflectors. During the day my Ricordea are noticeably smaller and dormant and my Kenya coral is about 1/3 the size compared to the night time. I know corals usually get larger at night to feed but they look a lot healthier as well. Also, my Clove Polyps look all stringy and worn out after a week or so. Do you think I have too much light or too much water flow for my corals which is causing them to shrink up? I get about a 1-inch wave with my Wavebox. <<I seriously doubt your issue is ?too much? flow unless you have the Stream pumps positioned such they are directly ?blasting? the corals. I really think your problem is you ?don?t have enough intensity/useful light spectrum? to allow the corals to photosynthesize properly. I urge you to consider reducing your Actinic lighting to about 1/5th your total wattage and employ 10,000K lighting for the remainder. Regards, EricR>>

Re: Too Much Actinic Lighting - 07/10/07 Would adding a 6500k daylight bulb work or do I need a 10k? <<Replacing the majority of the Actinic bulbs with 6500K bulbs would be fine, and are of even more "use" to your corals than the 10000K bulbs. I merely suggested the latter because they do provide enough "useful light spectrum" and are more aesthetically pleasing to the "human" eye for most hobbyists. EricR>>

Lighting, does Actinic count toward watts per gallon? 5/28/07 Hello again, and thanks in advance also. <Welcome!> I ordered the 180G AGA dual overflow tank and it should be arriving in two weeks. <Sounds fun!> I will have a saltwater set up with live rock and sand, fish, and some corals from the colony polyp and button polyp family. <Good to have a plan before setup. Knowing what you're getting into beforehand is so much more helpful, and eliminates many of the unknowns so we can deal with the ones that still pop up after our decisions are made. Cheers.> I've had a saltwater tank previously so I know I don't want a demanding reef. That said I'm looking at lighting and am requesting your advice and judgment regarding these two fixtures. <Will try, but light is ultimately up to the end-user to decide what they like, in conjunction with the needs of their animals.> For this 180g tank and the above life I mentioned I'm looking at these two lighting setups: 72 inch 4x96 Watt Current USA PowerCompact Orbit Fixture Dimensions: 72" L x 8.25" W x 4.5" H Daylight 6,700k/10,000k: 2 x 96 watt Actinic 420nm/460nm: 2 x 96 watt No. of Lunar Lights: 6 Total watts: 384 or 72 inch 6x96 Watt Current USA PowerCompact Orbit Fixture Dimensions: 72" L x 11.6" W x 4.25" H Daylight 6,700k/10,000k: 4 x 96 watt Actinic 420nm/460nm: 2 x 96 watt No. of Lunar Lights: 6 Total watts: 576 <Think I would be inclined to go with the six bulb configuration, *IF* you are planning to use two actinic bulbs like that.> I've read some of the info about wattage per gallon, but I'm not clear if actinic light wattage counts towards the total wattage of beneficial light. <Mmm, not really, no. It is (mostly) regarded as an aesthetic commodity, in that it doesn't stimulate photosynthesis. It does have other beneficial properties listed here and elsewhere on the web, most popular of them is the apparent boost in coralline algae growth, and reported inhibition of certain unwanted algaes, too.> Thanks again. <Welcome, sir. -GrahamT>

Actinic lighting, Cnid. use  4/22/07 Hello, <Howdy> I generally find all my answers in your articles and FAQ but this time I am a little confused.  I will try not to waste anyone's time here as you must receive more than enough emails.  So I will keep it simple and right to the point. <Like me!> I have a 29 gallon tank running 130 watts of PC.  I am going to start stocking it with mushrooms, polyps, and various other corals with photosynthetic needs.  As I look at my empty tank I really can't stand the sight of the actinic blue and want to know if pulling it out and running all white bulbs will affect anything. <Will improve most everything...> Currently all light is 10,000 Kelvin and I love how it looks.  The lighting article was a big help but I am not too sure if my setup is the best thing I can provide. <More "white" of whatever temperature would be better functionally>   One last thing.  I have been only considering coral species with light requirements labeled at MODERATE or LOW.  Am I over doing it if I consider a specimen with high light needs, or is this on a specimen by specimen basis? <Specimen and species... there is a range of "photo-adaptation/compensation" for both...> Always appreciate your insights.  Thanks so much for all the articles, FAQ pages, links, etc.  Thanks especially for giving your time. John Davis <Happy to share, assist you. Bob Fenner>

Kelvin Rating Issues...    2/16/07 Hi Guys: <Hi Joe.>   Thank you for your wealth of information. <Thank you for noticing....using.> I have a 90 gallon tank with two  150  watt 10,000k  HQI lamps and two 96 watt actinics. <Okay.> I know you guys say actinics are for enhancement mostly. <aesthetics for the most part yes...have some redeemable qualities but it is rare that I would recommend the use of high Kelvin temperature lighting exclusively on a reef....a tank with animals that are photosynthetic, hosting zooxanthellae.> Would I reap any benefit from switching out one of the 96 watt actinics to a 96 watt 10,000k bulb, and just leaving one 96 watt actinic. <No, the photosynthetic animals are deriving most of their needs from the MH bulbs, switching out the fluorescent bulbs will not make much of a difference par rating/intensity wise.> <<RMF would switch at least one of the actinics out>> I want to keep a range of reef creatures, but mostly LPS's and soft corals. <Then you are perfectly fine keeping what you have.> I was just wondering if I really needed  200 watts of actinics or could my lighting system be better utilized. <If you prefer the aesthetics of having all lower Kelvin bulbs (6,500k to 10,000k) I do not think it would be a problem, however what you have now will work equally as well for what you plan to keep.> Thanks again for listening and helping <Of course.> Joe <AJ.>

Actinics - necessity in the reef? 1/08/07 Hi Guys, <Hello, Jason. Graham with you tonight.> I had a quick question about lighting, I currently have both a 4x96w PC kit with a dual daylight and a dual actinic.   <plenty of light for a 30gal. Enough as far as I can tell, without a species list.> I have recently acquired a 1x175w 14k MH kit that I am going to install as I like the color better.   <Wow, does acquired mean free?> Would my tank benefit if I kept the actinics in along with the MH?   <Yes and no. Actually, I think that this topic is well covered here in the FAQs. http://wetwebmedia.com/marine/setup/lighting/actinicfaqs.htm Suffice to say that corals don't grow from the presence of actinic (420-450nm) light. They require light in the daylight spectra to really kick-butt. Don't forget to acclimatize the sessiles to the HID lighting!>> Also, I do currently have an assortment of corals.  Sorry I forgot to mention, its a 30gal tank.  I will probably be upgrading soon to something bigger. <I do love upgrades... fun!> Thanks for your help and keep up the great work. Thanks again, Jay <Thank you for the kind words, Jason. Happy lighting! -Graham T.>

Marine lighting... actinics, blue?   7/22/06 Hi I have a forty gallon reef aquarium with the orbit compact fluorescent lighting. It has a dual daylight (6700K/10000K) and dual Actinic (420nm and 460nm). I was wondering which bulbs would give the aquarium a more blue color? 420? 460? <The 420s likely> and if the 10000K would also give the tank more of a blue look than with the 67000K. <Yes> I was thinking of putting a 10000K built with either the 460 or 420. Or would it be better to put the 420 or 460 with a half actinic half 10000k bulb? <I would leave off with actinics...> The bulbs do not come in higher than 10000k or in actinic 03. thanks, Carl Brubach <See here: http://wetwebmedia.com/marine/setup/lighting/actinicfaqs.htm Bob Fenner>

Actinic Lighting Needed on a FOWLR? - 04/25/06 Hi Crew, <<Morning>> I have a 200 gallon FOWLR setup and was using 4 four-foot daylight bulbs.  I was wondering if I need to add actinic blue bulbs to my setup or are the daylight bulbs enough? <<Is just fine as is.  Regards, EricR>>

Actinic lighting... interesting perceptual question   4/7/06 Dear Bob,    I have a question as it pertains to actinic lighting.  Since I have added actinic 03 lighting to my tank I am noticing that the lighting causes a slight doubling of my vision when the tank is viewed from a slight angle.  Esp. noticeable on linear vertical markings that fluoresce in the light.  Others have noted the same effect on my tank I have tried reversing the end caps but I still notice this.  Any comments ?????  Is this rainbow effect?  This is not my imagination, nor do I have vision problems. Thanks Jimmy. <Don't know... but I don't think the vision effect has to do with the actual hook-up... just the light/spectra itself. Is a sort of "rainbow effect" perhaps in that the addition of a discreet bandwidth is somehow (maybe) challenging/offering to your brain two-sets of visual impressions to sort. Bob Fenner> Actinic Only? 01-13-06 I just purchased a VHO retro fit kit from a friend and he gave me the two actinic bulbs (only 1 month old) that he was using with it. He was also using MH lights with his setup, I however am not. I retro fit my CF strip with my new VHO fixtures but for the next week until my new bulbs are delivered I will be running my tank on VHO Actinic lights ONLY! They are two 24" 75watt URI VHO Actinic bulbs. My tank is comprised of assorted zoos, mushrooms, Yellow Polyps, Green Star Polyps and candy cane corals. Do you think that my tank will suffer ill affects from one week of Actinic Light only? <Your tank will be fine for a week. Just make sure you get some daylight bulbs over your tank A.S.A.P. Travis> The Difference between Superblue Actinic and Actinic 03  12-06-05 Hi there! <Hello> I have research your entire site about actinic lighting and I couldn't find the difference between actinics that are offered in the market today. Which Actinic will super enhance the coral and fish colors? <03 Actinics make them "glow".> Is it the Superblue Actinic? Or the Actinic 03? Or the Blue Actinic? The Actinic 03 bulb is more in purple color and the Super Actinic and Blue Actinic is more on real blue color. Which is best and which is the one that will enhance the corals and fish colors in my reef tank? <The lighter blue really made purples stand out in my tank. The 03 increased the "glow" of the greens and aided in blues, in my tank.> Which is more beneficial, the purple bulb or the blue bulb?. <They are very similar here with the 03 taking a slight edge.> I have a 40 Gallon reef tank with built in overflow. I have 24" deep tank. I have 1 x 65 W PC 10,000K and 1 x 65 W PC Actinic 03 and 1 x 24W T5 HO 10,000k and 1 x 24 W Blue Actinic T5 HO. In my reef are just soft, zoanthids, corallimorphs, brains, bubbles, Blastomussa, Micromussa, cup corals, frogspawn and hammer .All light loving corals are placed well above, about 5 inches from the light. Is this lighting sufficient? I would like to add one more pair of T5 HO fixture but I am not sure which actinic color will enhance the corals and fish colors? <I suggest the 03's, but it is going to be more personal preference than right or wrong.> I like the way the corals color when just the actinic 03 is on and also the blue moon light seems to give more color to the corals and the moon lights are not purple in color but blue. My plan is to duplicate the color that the actinic is doing to the corals but with all my 10,000 k bulbs on. Is this possible to do? <Yes and no. The Daylights will always fade the actinics a bit, but you will still see the "glow" from the 03's. It just won't be as noticeable as when the daylights are off.> The T5 HO lighting fixture that I am planning to add will have two bulbs in it. Is it best to put one actinic and one 10,000k, and if I do that, will I get the color that I am looking for? <Sounds to me like you would be happier with 2 actinics.> Or is it best to put 2 X actinic and if so which actinic I should go for? <What ever you think looks best.> and If I do this, is the 2 X 10,000k that I have now in my reef tank enough for my corals to grow? <That lighting would be enough to get the corals to grow, but you will honestly see more growth with every watt of white/yellow light you add. So, the blue may look nicer, but the corals will grow slower. It is a fine balance to have perfect color and growth.> Please answer back in as simple as possible to understand and I do appreciate your time. I thank the whole WWM crew for all the help that you guys are doing in helping every hobbyist succeed in this expensive but very rewarding hobby. THANKS AND HAPPY HOLIDAYS '05 TO ALL OF YOU. <Thank you and Happy Holiday to you and yours also. Cheers, Travis> 

Actinic Light - 11/27/05 Hey Crew, <<Hey again Jenn>> One more question... <<Ok>> Forgot to mention that I have a 96watt Coralife all actinic light, in addition to the 400watt 20k MH... I read that the actinics are better for deeper water species, and the SPS and shallow water species prefer daylight or 50/50 bulbs?? Is this true? <<The 10K bulbs provide enough blue light for all, and are better for SPS in my opinion. The actinics are more for the aquarist (aesthetics).>> Thanks so much. Jenn <<Regards, EricR>>

Cyanobacteria and lighting  11/16/05 Hello, I have a 180 g FOWLR w/ 150 lbs of LR. Phosphates <.01, Nitrate 25 ppm, pH 8.2, Calcium 400, Alkalinity 13 dKh. Running Turboflotor Multi, ozone ORP 350, Small refugium with Gracilaria. Lighting 320 w VHO. 160 w Actinic 03 and 160 w of actinic white 12,000 K. On 5 hrs daily. I am starting to see some Cyano on the back panel. I have great coralline algae growth on rocks (pink, reds, greens ) Can I do anything different with lighting to encourage coralline and discourage Cyano? <Oh yes... trade out a good deal to all of the Actinics> Would two 160 w 12,000 K bulbs be better ? <Mmm, yes> Would a longer photoperiod be better, if so, how many hrs ? <More white, more hours...> Would a different spectrum of bulbs be better i.e. 12k and 10 k both 160w ? Thanks Jimmy <Mmm, not IMO... unless for your livestock, esthetics, you have a compelling reason to change. Just switch out some/all of the actinic... you'll lose some encrusting reds, but likely the Cyano as well... and do read on WWM re: http://www.wetwebmedia.com/bluegralgae.htm and the linked files above. Bob Fenner>

Re: Cyanobacteria and lighting  11/16/05 Hi, Just one follow-up question. Does Actinic lighting alone favor Cyanobacteria ? <Mmm, in a manner of speaking/understanding, yes. This spectra does not favor other/"higher" algae/thallophytes... which would/will compete for nutrient, light... delimit BGA growth> My fish seem to feel much more at ease with just actinic on.  So New Plan 180 g FOWLR.  Wake up to Blue actinic light ( 60 watts Standard Output ) in 6AM 15-30 min then add 320 w of 12K on for 1 hr ( Feeding time in AM ) After 1 hr only light is ambient room lighting. Actinics off for rest of day with 360 w VHO 12 K on for 8hrs between 1PM and 9PM.  Actinics on at night only 30 min after VHO turned off ( for transition 845PM -915 PM ).  Refugium : 10 hrs lighting 10 K at night.  Sound OK ? Thanks <Mmm, please read where you were sent to. Bob Fenner> 

Excessive Coralline Growth And Light Spectrum - 11/12/05 Dear Bob, <<EricR here tonight>> I have a 180g FOWLR acrylic tank. I have approx 150lbs of LR since Sept. 2005. Nitrates 25 ppm, phosphates < .01 ppm, alkalinity 13 dKh, Calcium 400, pH 8.2, ORP 310- 325 w/ozone. <<Mmm, pushing the limits on the calcium and alkalinity...in my opinion.>> Lighting 160w VHO actinic 03 160w VHO actinic white URI on 5 hrs. per day 60w actinic 03 on 12 hours per day. <<Way too much actinic.>> I have had incredible coralline algae growth everywhere in the aquarium. <<Replace all those actinic bulbs with 10000K bulbs and you'll likely see a decrease.>> I have to scrape front and side every three days. After I clean the back of the tank, within days pinpoint colonies of coralline algae emerge. <<Not surprising with your current light spectrum.>> With an acrylic tank I really have to stay on top of this if I wish to keep acrylic surfaces clean. <<I understand, I too have an acrylic tank.>> Should I let the back of the tank go on to grow pink, purple, green corallines? <<I would>> Am I doing more harm than good by trying to keep the back clean? <<Doubt you're doing any harm...but if you're not viewing through the back, why go to the trouble?>> Thanks Jimmy <<Regards, EricR>>

Blue Actinic Supplemental Light  9/2/05 Hi, We have 3 250 10k Halides.  I would like to keep that temp to encourage growth.  We also have 4x96 watt PCs from an older tank that we are thinking of adding.  We'd like to get a nice affect to look at, but don't want to "waste" the electricity if they won't help the corals.  Would you recommend actinic 03, 7100 or either of the (2 phos temp bulbs- 420 or 450 I think) for both color and improved growth/health? Thanks! <Doug, what size is your tank?  James (Salty Dog)> Doug

Re: Blue Actinic Supplemental Light  9/3/05 It's a room divider that is a little over 200 gallons.  24" deep with a DSB (3" at the sides / 6" in the middle).  Thanks in advance for your advice! WWM FAQ Crew <crew@mail.wetwebmedia.com> wrote: Blue Actinic Supplemental Light Hi, We have 3 250 10k Halides. I would like to keep that temp to encourage growth. We also have 4x96 watt PCs from an older tank that we are thinking of adding. We'd like to get a nice effect to look at, but don't want to "waste" the electricity if they won't help the corals. Would you recommend actinic 03, 7100 or either of the (2 phos temp bulbs- 420 or 450 I think) for both color and improved growth/health? Thanks! <Doug, your lighting gives us about 3.75 watts per gallon which should be fine for soft corals.  Hard corals and clams do better at 4+ watts per gallon.  I would supplement the PC fixture with two true actinic (420) and two 10K bulbs. If the tank receives indirect sunlight from a window etc, you should be OK as you are.  James (Salty Dog).  Also, when replying, reply with original message so it can be routed to the WWM writer.> Doug Lighting combination question part 2 8/28/05 Hello, So there it would not make a difference between if they were actinic or white lights? Thanks WK <The two combinations you proposed would probably not make any difference to the corals, only the appearance of the tank.  A lot of people believe that having some actinic helps the corals develop better coloration as well as make the tank look better.  If anything, all white light would provide more intensity to the corals, but you may find the appearance of the tank unappealing.  Best Regards.  AdamC.> Actinic...Which Wavelength? - 06/04/05 Hello, <<Howdy>> I have a question about actinic lamps, I see that manufactures of compact fluorescents are making 420nm and 460nm wavelengths, now my question is what is a better lamp for our reef tanks I know that the 420nm has been around for a while but some of these manufactures claim that the 460nm is more of a real world lamp in terms that it is a better spectrum for zooxanthellae to thrive. <<I think the key here is that this is being touted by those that SELL these lamps.>> Now can you tell me what the difference is?  And what is a more suitable lamp? <<Have a read here: http://www.wetwebmedia.com/marine/setup/lighting/actinicfaqs.htm>> Thanks, Lonnie <<Regards, Eric R.>>

Lighting... silly question 1/30/04 In advance, thanks for the help. <very welcome> I have read in several books, including the Marine Reef Handbook, regarding lighting. According to the authors, blue light (actinic) is enough to keep symbiotic corals/false corals happy and alive, and that "white" light is just used to allow us humans to be able to view our specimens. <if the statement has been recited true, then it is incorrect. I have not read this passage that you cite, but can assure you that the opposite is true for most corals. Any look at studies on corals and symbiotic activity in the last 5 years has demonstrated that all commercial lamps 6500 K (yes... this daylight color) and higher have enough or too much blue light for our corals. It may be "too much" blue in the sense that it is produced by the lamp at the expense of producing more useful "white" light> If this is true, then why all the hoopla about requiring VHO's/PCs/Halides with white/yellow output....? <exactly... the statement is not true> Jess Bansal <Anthony>

Actinic lighting - 11/4/03 Hi, My tank lighting is fluorescent tubes, I have had 1/2 actinic, and 1/2 full spectrum. <What kind of fluorescent lighting are we talking here? Standard (NO), VHO, HO, or PC?> However, the person at my LFS has told me that it is the actinic that is needed by organisms containing zooxanthellae, so I have now gone to 3/4 actinics. <Mmmmmm. Well..... right to a degree....have you read through our article and FAQs on lighting?? http://www.wetwebmedia.com/marine/setup/lighting/fluolgtgmar.htm http://www.wetwebmedia.com/marine/setup/lighting/index.htm http://www.wetwebmedia.com/marlgtganthony.htm In any event, I am not so sure I am sold on high actinic lighting, and here is some of my reasoning (warning: not scientific): I work in the husbandry department of a major public aquarium here in the Bay Area and all that we use is metal halide lights ranging in spectrum from 6700K and 10000K. (10000K being a more blue in the Kelvin scale) We have never employed the use of actinic on a single reef tank yet. The growth is very  prolific for all SPS, LPS and soft. I personally employ only 10000K lighting for various coral tanks as well (I use Power Compact). I personally don't think a tank without actinic lighting will affect corals one way or another. <I do like the balanced blue with a 6700K or 10000K but I feel the 10000K provide enough blue for PAR) Now, I have no scientific research or even a true test harness to correlate my feelings and impressions. (I am somewhat sure someone out there could give you true scientific data regarding the growth and mortality of corals with and without actinic lighting maybe Sanjay Joshi or Craig Bingman?) I can tell you, we haven't seen any side effects without actinic lighting for the past few years without it>  However the overall effect is a slightly darker looking tank, although things are fluorescing more,<normal and expected> so just wanted a second opinion. <Read the above> It is currently a softies only tank along with a Hydnophora and various polyps and mushrooms. <Should be fine, but I believe these coral choices with the exception of the Hydnophora, would be appropriate even for NO lighting, for the most part. Again, I don't believe you need to rely so heavily in actinic as you should go for a display that looks natural and appealing provided the inhabitants needs are being met first. Lighting output, spectrum, and intensity make a difference> However, in case I ever move up to SPS or whatever, I would also like to know what ratio of lighting I should use in this event. <Not a matter of ratio in my opinion as much as I believe that you have provided enough PAR for photosynthesis at the proper wattage output (intensity) and at the proper spectrum. Most high end aquarium lighting systems today, provide enough blue light at the 10000K spectrum for photosynthesis. Another important aspect to coral keeping is feeding. It is my belief that photosynthesis alone is not enough to keep corals alive. They are feeding at some level aside from photosynthesis.>  I cannot go MH as heat is an issue. <OK... Nothing can be made to mitigate the heat issue? Be sure you provide the proper environment before purchasing a particular animal or coral.> And, thanks for the great service you provide. <Thank you for your question. -Paul>  Cheers, Alastair

-20k versus actinics- Hey everyone.. Just a quick question or two regarding lighting.  Well I hope it's quick anyway.  Has there been any coral growth difference noted when using 20K MH bulbs as opposed to VHO actinics?  Good or otherwise? <The corals seem to benefit by the increase in intensity, as well as from the added spectrum of the 20k lamp.> I know corals can thrive on the actinic spectrum when it is placed close enough to the water. <Only actinic?!> Could/Would we expect the same type of growth from 20K MH? <Many aquarists get incredible growth under 20k lamps. It's important to note that lighting is only one of the many variables that goes into how well a coral thrives (available calcium and alkalinity, and proper water movement are also critical). I get great growth, and use 10k 400w lamps. Basically, it's not just the bulb, you could have excellent growth under most lamps provided everything else is in check.> If I used a 20k in between two 10K bulbs, all with spider light reflectors in a 48" tank.. would I expect to see a "blue spotlight" in the center or would the reflector disperse the blue light evenly over most of the tank? <It would be noticeably bluer in the middle. It would be worth a shot, but you may not be happy with the results. Dig around the forums for pictures of tanks with this same setup.> I can't say enough what a God send this website is, not to mention the wonderful people who keep it running.  You are all an inspiration to aquarists everywhere. Thanks once again for everything and anxiously awaiting the next volume in "Natural Marine Aquarium" series. <I hope I've been of some help. -Kevin> Jeremy - Pineville, LA

What is the benefit of actinic lights ? Hi, great site, Ok here is my tank set up 11 months with 55 FOWLR, 40 lbs of rock, 1 jawfish, 2 damsels, 2 true percula clowns, 3 yellow clown gobies, and one fat lawnmower blenny. I currently have a 48" satellite powercompact with 2 dual actinics and 2 dual daylight 10,000k \6700k. I have heard different things about the actinic lights, do I need them for the live rock, i.e. calcareous algae. <Nope> If not I would like to switch out the actinic lights for 2 50/50 or just another set of dual daylight bulbs. <I would do this> I'm just trying to get a brighter looking tank. Do you think it would be harmful if I get rid of the actinic lights? <Not at all> I'm thinking of rescuing a anemone from the LFS and just want to make sure the lights will not harm it.  Thanks. <The functionality of aquarium "actinics" is minimal. I would switch these lamps out as you state. Bob Fenner>

Why do I need blue light? Thanks again Adam. I've had freshwater fish since age 3 or 4. My SW experience is <5 years, with <1 year for a reef tank. So a yellow tang doesn't bother me... if that's the reason you recommend more blue.  < More blue really does help out with coral color. It excites and stimulates the corals to produce more pigments. > Narayan PS. I see you listed as a speaker for MACNA XVII. I'm going to try to make it... as long as I'm still in the North East! ...long story! < I am looking forward to MACNA and appreciate their offer. See you there! > 

Wattage Deprived Corals? Hi Crew (Not sure who's answering this), <You have the new guy Justin> My jaw dropped when I read this article/answer by Anthony regarding Actinic wattage doesn't really count? 9/13/04. Copy of article is at the end of this email. <I know the one you are referring to> I've had a 55gal reef tank for 6 years now.  My corals include mushrooms, polyps, candy canes, a hammer, colt, and cabbage. My lighting currently are two 65watt 10,000k daylight & two 65watt 420nm Actinics PCs by Sunpaq. <a good setup in for a 55 gallon> My 1st Question: I thought I had (4x65)=260watts of light gleaming through my tank, which is roughly 4.7watts per gallon. I realize coral placement fits into the scheme of things. If Actinics don't provide health benefits am I really looking at only (2x65)=130watts of helpful coral light? <Not exactly, It is a tough question to really answer. As far as the total lighting you have around 260 watts. The difference is counting usable watts of light.> My 2nd Question: If Actinics are more for us than corals, is it safe to say I could just by a cheap T8 of T12 actinic fluorescent bulb for looks and go with all four 65watt 10,000k daylight PCs for the corals? <You certainly can it will help in general with growth over the actinics single wavelength> My 3rd Question: Is there any advantage to wattage when it comes to an actinic? (other than visual). <Well it does over-stimulate the 420-450nm wavelength which is very important for photosynthesis and it also suppresses algae growth that is not deemed beautiful by aquarists.> Please set me straight...I've never come by this before!  Thanks Crew! Sincerely, Clayton <Well actinic lighting is mostly for our benefit as it colors the water and offsets the yellowing that is usually seen by daylight spectrum bulbs. The 10,000k bulbs you have don't suffer from this yellowing as the tap into the blue end of the spectrum already. If you are really concerned with the best growth you can possibly get you can trade out the actinic PC lighting and go with more full spectrum bulbs. It is more of a personal preference as actinic fluoresces colors on fish and in the tank to bring out the brightest color you can get, since daylight suppresses some of the more vibrant ones. If you really enjoy the actinic look going with two 40 watt fluorescent lights in actinic T!@ or T8 would be fine, you can even get them as true actinic to get that extra boost of photosynthetic light as well but it is really up to you as to tastes. the best rule of thumb that I have known is that the least amount of actinic used to get the look you want is the best to use so that you get as much full spectrum as you can. I will forward this to Anthony for his take on this as well. Hope this helps. Justin (Jager)>

Wattage Deprived Corals 2 Thanks Justin. <No Problem> A quick question. You mentioned Actinics 420-450nm wavelength <Yes most true actinic bulbs phosphor coating produces light in the 420nm-450nm range through out its lifespan> which is very important for photosynthesis. However, Anthony states this in his article: <rather simple... actinic light is (more or less) a single wavelength. There are a few lamps/wavelengths out there, but they are in the 420 nm range.  Yes most actinics are 420nm BUT the catch is that the phosphors they use do not project just at that wavelength they hit a range from 420-450 especially as they age> This does not adequately stimulate zooxanthellae in photosynthetic corals. <Correct, it only stimulates the zooxanthellae that are in that range> You typically need a daylight spectrum in the 6500- 10k K range (a bit of a generalization here speaking to the popular coral species kept)> Can you see my confusion? Can you and Anthony "shed some light" on this?  <Yes, here is what it really boils down to. each photosynthetic animal has various zooxanthellae that respond to different wavelengths of light, so if you use full spectrum lighting it ensures that all of those different wavelengths are covered, but in varying degrees of wattage as the bulbs wattage is divided among the wavelengths. actinic over produces one wavelength at full strength because it doesn't have to produce any others. Actinic's wavelength of 420nm is very crucial for photosynthesis, but it cannot be the only wavelength for photosynthesis or animals would starve in nature since actinic is so specific. actinic is more to outweigh the yellow effect that most daylight bulbs get over time as they age or the 6500's have normally. The lighting mimics the sun so it has to be yellowish to get all the wavelengths. Your 10,00k bulbs lose the yellows and operate at a higher color temperature that still supplies enough various full spectrum lighting to ensure photosynthesis. you really do not need actinics as I said before, you only can use them for your own taste in color of the tank. if you are worried about it please change all of your pc lighting to full spectrum bulbs and get a 20 dollar 2 bulb standard fluorescent t12 or t8 set with two actinic bulbs to get the right color. Hope that clears it up> <Justin (Jager)>

Actinic Wattage Doesn't Count? Anthony Clarifies Jaeger's Answer - 2/27/05  <it's not that Actinic has little value, my friend.. but taken in the context of folks writing in with queries and commenting that they are using (too) blue MH lamps and want to add even more blue (fluorescent) lamps... it is too much. MH's at 14k K or 20k K are too blue for many popular corals. The heavy weigh on that side of the spectrum is given at the expense of some watts being used that could otherwise drive more daylight colored lamps. In this context... there is such a thing as too much blue.  THE defining param... to qualify this is PAR values for coral. Do compare the PAR values of excessively blue lamps with that of more daylight leaning colors (6500-10k K)... the latter have better PAR values (measure of a lamps ability to stimulate photosynthetic activity). Do enjoy your blues! Just don't get too heavy ;) Anthony>

STILL CONFUSED!!! Actinic Wattage Doesn't Count Hi Crew, <Justin here> Please help me... I'm still confused. <Will do my best> Is there a clear answer to this issue, or am I stuck in the dark?  <Argh more puns.... :) > In blue is my latest, unanswered question. In purple is the dialog that that lead to it.  <Ok, but I had to take off the oldest message due to space issues> Please help. I want to make sure I have adequate lights for my corals. <Sure> A quick question. You mentioned Actinics 420-450nm wavelength, which is very important for photosynthesis. However, Anthony states this in his article: <rather simple... actinic light is (more or less) a single wavelength. There are a few lamps/wavelengths out there, but they are in the 420 nm range. This does not adequately stimulate zooxanthellae in photosynthetic corals. You typically need a daylight spectrum in the 6500- 10k K range (a bit of a generalization here speaking to the popular coral species kept)> Can you see my confusion?  Can you and Anthony "shed some light" on this? :) <Ok I will break this down as best I can , though I think in the second email you sent I did this, maybe it was lost in cyberspace, Anyway, actinic light by itself is not enough to keep corals. Your tank would be better off and see more growth if you switch out your actinic PC bulbs, and replace them with more full spectrum bulbs. If you prefer the look of actinic you can either get a 50/50 bulb for one or get a 20$ fluorescent light fixture from Lowe's or home depot and get two actinics or two blue colored bulbs. Bottom line: You have adequate lighting, but you could get more growth by switching out the PC bulbs as I said. And a wave length for actinic is 420-450 range which means that one wavelength can alter a bit over time but it is still in that NM range and is one single wavelength that degrades over time up or down. Hope that helped> <Justin (Jager)>

STILL CONFUSED!!! Actinic Wattage Doesn't Count - Part Infinity Thanks Justin, <No problem> I just was just paranoid when I read Actinics 420-450nm wavelength which is very important for photosynthesis statement, and was wondering how much or little to use. <Yes it is very important, but not nearly as useful to anything photosynthetic s good old full spectrum. It has a higher PAR which is always the best way to measure usability in keeping photosynthetic animals.> Now I understand. Maybe that's why my Bubble and Hammer deteriorated slowly over months...not enough 10,000k. <Well 10,000k is up there for PC lighting, I would possibly try adding 6500k or something with the highest PAR value you can get, as well as a high CRI value (6500k is the closest to "true" sunlight in PAR and CRI values> Aquaculture, the never ending learning curve.  No puns this time!  Thank you very much Justin. <Once again happy to help. I am just sorry we couldn't help you understand earlier and left you confused for at least a week with no word back that you were confused still. But I am always glad to help, and hope things work out well for you.> <Justin (Jager)> 

SPS Lighting I have a 72'x28'x18' tank, planning to keep SPS .I already purchased 3 HQI MH ,Giessemann,250 watts, 20,000k. Do I still need Actinics or that will do the job? Their blue color is amazing though. Thanks. >>>Greetings, Great choice on the lights! The Giesseman fixtures are second to none. You never NEED actinics, and with your 20K bulbs I see no reason for them even if you like the "blue look". Your color rendition should be fantastic with this setup. Cheers Jim<<<

PC vs. VHO Actinics what's the difference between the pc and VHO actinics? < It is mainly personal preference.  I think the pc give off more light per area.  However, if you have a tank feet long, then a VHO bulb fits much better than a pc bulb.  Also, to me VHO bulbs appear to be better for actinics. > <  Blundell  >

29 Gallon - 2x65 Watt Orbit PC Hey~ <How goes it?> I am trying to figure out if I should remove the actinic lighting from my fixture and install another 8,800 K bulb -- its seems from what I am reading that the actinic doesn't offer much. <Actinic doesn't provide much PAR (photosynthetically active radiation), it's used mostly for aesthetics.  However, it all depends on what you're looking to keep.  Can't give you much advice without more info> Thanks Rob <M. Maddox>

Re: 29 Gallon - 2x65 Watt Orbit PC Thanks  M. Maddox <Glad to be of service> I have some mushrooms, polyps, zoos -- no SPS or LPS (figured I would need to upgrade my lighting to keep those). <Quite so> Have about 35lbs of live rock, 2in. SB - BAKPAK skimmer and 2 powerheads. <Sounds good> Is that the info you need? <Yep, all low light creatures.  If you'd like more\faster growth, swap out an actinic for a daylight> Thanks again <No problem> Rob <M. Maddox>

Lighting Clarification, functionality of actinics, anemones... I've been reading on your website through the anemone lighting FAQs, and several of the WWM crew keep saying that an actinic bulb doesn't really provide any benefit other than aesthetics.<I find that hard to believe.  Within the blue band there is a chlorophyll absorption peak at about 420 nanometers, and the actinic also peaks at this wavelength.  The light is then used by zooxanthellae that live within the tissue of the anemone, in turn they produce fats, sugars, etc as food for the anemone>  James I have a 40 gallon breeder with a rose anemone in it, I have one 96 watt 6700k daylight PC and one 96 watt Actinic 03.  Does this mean I should replace the Actinic 03 with a 6700k daylight? Would two 6700k daylights be more appropriate as lighting care for this anemone? Are actinics really not beneficial? I was under the impression, like the advertising always says, that it stimulates the anemone zooxanthellae (sp hehe) and provides important spectrum and is important for the well being of the anemone. Please let me know the best combination based on your knowledge. I was thinking I could get two 6700k 96's and then add on one normal output 30 watt actinic, I don't want to waste 96 watts of my PC ballast on a bulb that isn't giving my anemone what it needs.  Thanks for any advice, opinions, etc, Dennis

Re: Actinic Lighting Clarification I'm more confused now! Actinic or not? <My answer should have removed any confusion Dennis. Use an actinic bulb>  James (Salty Dog)

Re: Lighting Clarification Ok, I'll get the actinic 03, but all of the wetwebmedia lighting threads are confusing!<Some people prefer VHO to PC to MH, but the 420 spectrum needs to be there in some way or form for corals to survive.  Some people have said just using 10Ks will do it, but I've never tried it>  James (Salty Dog)

Lighting Clarification, a difference of opinion, fact? I've been reading on your website through the anemone lighting FAQs, and several of the WWM crew keep saying that an actinic bulb doesn't really provide any benefit other than aesthetics. <Mmm, such didactic statements are not quite accurate... I'd like to state that actinics don't do "much" functionally... that their use is much more aesthetic> I have a 40 gallon breeder with a rose anemone in it, I have one 96 watt 6700k daylight PC and one 96 watt Actinic 03.  Does this mean I should replace the Actinic 03 with a 6700k daylight? <If you were more concerned with aspects of the animals health, yes> Would two 6700k daylights be more appropriate as lighting care for this anemone? <Yes> Are actinics really not beneficial? <Not "much"> I was under the impression, like the advertising always says, that it stimulates the anemone zooxanthellae (sp hehe) and provides important spectrum and is important for the well being of the anemone. Please let me know the best combination based on your knowledge. I was thinking I could get two 6700k 96's and then add on one normal output 30 watt actinic, I don't want to waste 96 watts of my PC ballast on a bulb that isn't giving my anemone what it needs.  Thanks for any advice, opinions, etc, Dennis <You ask a good question, and I would like to point you to specifics... there are actual reportings, studies of actinic lamps, PAR values, their utility with anemones, zooxanthellae... but I don't have quick access from home with the computerized bibliographic tools to cite them here/now. I would encourage a visit to a large library for this task. Some background on how to do these searches here: http://www.wetwebmedia.com/litsrchart.htm Bob Fenner>

Lamp colors and Refugiums 11/9/04 I have a couple quick questions.  I'd like to know what the difference is between the 7100k lights and the actinics.   <actinics are a single wavelength (around 420 nm for some) and 7100K lamps are a full(er) spectrum akin to daylight. This latter lamp being much better for PAR for corals> I know the actinics are specific to 420nm which I've heard doesn't do much for photosynthesis, however, great for aesthetics.   <Doh!... I should read ahead. Yes> The 7100k lights I've seen out on the market look pretty similar in color to the actinics, but I've been told they're much better for photosynthesis.   <correct... do look at PAR values in charts and analysis... articles by Sanjay Yoshi for example> Another confusing thing is that a 6700k looks yellow and a 10k looks more white but a 7100k which is in the middle of the two looks blue??   <different brands and even interpretations by individuals (we all do not see color the same)> I just would like to know what the deal is with all this. One thing that I've been looking forward to is the next book in the natural aquarium series.  Could you tell me what the schedule of releases are?   <we are getting into layout and pre-press now... hoping for the first of a 2 part-volume on Reef Fishes for early next year> I've learned a ton from just the invert book.  It's inspired me to get a refugium.  I don't have one yet but it's in the works.  BTW have you had any experience with the ecosystems refugium method? <yes, and many refugium styles> Is it really that much better than a standard refugium growing less dangerous algae.   <of its many benefits I would not count that as one. Water flow is more of a factor here> I've also become a firm believer in the quarantine tank as well. <this is a critical lesson... it will take you far> I tell all my customers to quarantine quarantine quarantine!   <all will succeed better for it. Thank you for this effort!> Well this has turned out to be quite long so I'm  going to cut this short.  You guys are great thanks a mill. Chris aka fishtank <best regards, Anthony>

Actinic wattage doesn't really count? 9/13/04 This note is directed mainly toward Mr. Calfo, <please call me Anthony, my friend> but if anyone has feedback, I'll surely listen... Anthony, in an article you wrote recently that was posted at www.MarineDepot.com (I love that vendor!) <ooh, yes... agreed. I like Marine Depot/Ken Wong very much too> you passingly commented not to count the wattage of actinic lights when calculating how much wattage per gallon you're giving your tank. <yeppers> Could you elaborate on this? <rather simple... actinic light is (more or less) a single wavelength. There are a few lamps/wavelengths out there, but they are in the 420 nm range. This does not adequately stimulate zooxanthellae in photosynthetic corals. You typically need a daylight spectrum in the 6500- 10k K range (a bit of a generalization here speaking to the popular coral species kept)> I haven't found anything else (anywhere, not even WWM!) that mentions this (?). What exactly is it about actinics that they don't do much for the corals? <lacking full spectrum for zooxanthellate corals> I do remember reading around that actinics are good to help keep nuisance algae growth down, <ah, yes... and they keep coral growth down for the exact same reason - lacking full spectrum daylight, they do not support adequate photosynthesis> as most of them thrive in low (red) light, & that the actinics blue wavelengths make it to the bottom more efficiently. <hmm... sort of. Red light is high end/shallow water spectrum where most corals and algae grow> Aside form that, would it be correct to say that actinics are more for "us", the aquarists, than "them", being the corals? <yes.. a fair summary> Slowly becoming enlightened, Pete Cushnie <as we all are mate... kindly, Anthony>

Actinic bulb, 25w 30in., for a 45g Via Aqua Tank (6-3-04) Hi, <Hello> I am having the hardest time finding a 25 watt 30 inch 100%blue light for my via aqua tank. It is very frustrating. <I can certainly understand your frustration.> Do you know anywhere I can get the bulb? <No, not specifically , sorry :(. > NEC's website is way to hard to figure out I tried there first because my white lights are from NEC. < That is a fairly new tank on the market. The bulbs must be available. I would recommend you start with the shop where you purchased the tank, it seems to me if they stock the tank they would also stock lights or at least be able to order them for you. You do not specifically need NEC bulbs. There are many manufactures of bulbs. You could also call or email the manufacturer of the tank and inquire about what bulb options you have available and if they know where they can be purchased. If neither of those options pan out there are several very helpful retailers online. My suggestion would be to contact a few of those that carry Via Aqua products. I prefer the phone to email for this sort of inquiry. Ask them if they can special order you a bulb if they do not stock them. >  The Japanese need to simplify there sites to plain Jane English, not all measurements that make no sense. < I have trouble with their directions as well. I suppose it is simple to them, they would probably like us to simplify ours as well :). There are several online conversion calculators they are very helpful when dealing with the different standards of measurements......I like this one http://www.onlineconversion.com/ > I would appreciate all the help I can get. <That's about the best I can do. I hope it was somewhat helpful>  My tank is doing very well for a new tank and has lots of great life going <Super !!> on but I want the blue light to help my cleaning crew keep the algae away (the bad algae). <Good Plan> Leslie

Actinic as a Moon Light? >Hello brilliant boys and babes: >>Hey.. what's the sizzle? >What's happening?  You guys are the hammer that knocks the nail in!  Is it okay to use a fifteen (15) watt actinic03 NO fluorescent lamp as a night-light on my 55g tank?    >>As a "nightlight" as in to keep on all night?  If so, then no, I  wouldn't do it.  If just for low wattage lighting for after regular lights out, then sure. >Is the wattage so low, that it does not matter what I have, or can it bother some inhabitants?   >>It could bother some inhabitants, but honestly it's something I've never done, so have no experience with.  When looking for evening lighting I ended up using one of those battery powered "tap lights", which was always turned off before going to bed. >If it matters, I have mostly FOWLR, with three "silver-dollar" size leather frags, and one small orange mushroom frag that just had a "baby".  If it's okay as a night-light, is that thought of as moonlight, or am I totally missing the point?   >>No, if you want a "moon light", then consider what light comprises moonlight, that is to say "reflected sunlight".  Quite dim, and I couldn't tell you what spectrum is received off the moon, but I would expect that it's a bit broader than the 420nm that actinics are specific to. >Should I look to adjust it throughout the month, like phases of the moon?   >>I don't think so, as you can't adjust the gravitational pull that seems to still affect many sea creatures whether or not they get "moon lighting". >One last thing; should that be on a timer, or shoot, just leave it on always (being drowned out during lights-on)?   >>In the name of energy efficiency, I would put it on a timer so that it's not only not on when the regular lights are, but so that it's not on all night.  As you know, the moon's not out all night long, either. >WHEW!  Thanks a million, I will follow you folks until the end! Rich. >>You're welcome Rich.  Now go have fun.  Marina

Lighting... silly question 1/30/04 In advance, thanks for the help. <very welcome> I have read in several books, including the Marine Reef Handbook, regarding lighting. According to the authors, blue light (actinic) is enough to keep symbiotic corals/false corals happy and alive, and that "white" light is just used to allow us humans to be able to view our specimens. <if the statement has been recited true, then it is incorrect. I have not read this passage that you cite, but can assure you that the opposite is true for most corals. Any look at studies on corals and symbiotic activity in the last 5 years has demonstrated that all commercial lamps 6500 K (yes... this daylight color) and higher have enough or too much blue light for our corals. It may be "too much" blue in the sense that it is produced by the lamp at the expense of producing more useful "white" light> If this is true, then why all the hoopla about requiring VHO's/PCs/Halides with white/yellow output....? <exactly... the statement is not true> Jess Bansal <Anthony>

UV Protection- Worth The Extra Money? (Lighting Confusion) Hi Scott <Hello again!> At my LFS I noticed a Sylvania globe that has a UV filter or UV protection-something of that kind included, noticed it was also more expensive than the normal Sylvania globes of the same size. What are these all about and are they worth getting in terms of the extra money? <If you are not using a cover of some sort over the tank, there may be some merit to this. You may need to ask the LFS what these bulbs are...> Are there any additional benefits as I am gonna be buying another actinic globe within the next few days and if you think the one with the UV thingy is the way to go then I might as well spend a bit more while I am at it and go for that one. <I cringe when I think of making a bad recommendation here- but I'll take a chance and suggest the "regular" actinic bulb that you've been using. Do discuss the particular bulbs that you're seeing with the LFS personnel...> Please advise Thanks Again Regards Ziad Limbada <Any time, Ziad! Happy New Year! Scott F.>

Actinic lighting - 11/4/03 Hi, My tank lighting is fluorescent tubes, I have had 1/2 actinic, and 1/2 full spectrum. <What kind of fluorescent lighting are we talking here? Standard (NO), VHO, HO, or PC?> However, the person at my LFS has told me that it is the actinic that is needed by organisms containing zooxanthellae, so I have now gone to 3/4 actinics. <Mmmmmm. Well..... right to a degree....have you read through our article and FAQs on lighting?? http://www.wetwebmedia.com/marine/setup/lighting/fluolgtgmar.htm http://www.wetwebmedia.com/marine/setup/lighting/index.htm http://www.wetwebmedia.com/marlgtganthony.htm In any event, I am not so sure I am sold on high actinic lighting, and here is some of my reasoning (warning: not scientific): I work in the husbandry department of a major public aquarium here in the Bay Area and all that we use is metal halide lights ranging in spectrum from 6700K and 10000K. (10000K being a more blue in the Kelvin scale) We have never employed the use of actinic on a single reef tank yet. The growth is very  prolific for all SPS, LPS and soft. I personally employ only 10000K lighting for various coral tanks as well (I use Power Compact). I personally don't think a tank without actinic lighting will affect corals one way or another. <I do like the balanced blue with a 6700K or 10000K but I feel the 10000K provide enough blue for PAR) Now, I have no scientific research or even a true test harness to correlate my feelings and impressions. (I am somewhat sure someone out there could give you true scientific data regarding the growth and mortality of corals with and without actinic lighting maybe Sanjay Joshi or Craig Bingman?) I can tell you, we haven't seen any side effects without actinic lighting for the past few years without it>  However the overall effect is a slightly darker looking tank, although things are fluorescing more,<normal and expected> so just wanted a second opinion. <Read the above> It is currently a softies only tank along with a Hydnophora and various polyps and mushrooms. <Should be fine, but I believe these coral choices with the exception of the Hydnophora, would be appropriate even for NO lighting, for the most part. Again, I don't believe you need to rely so heavily in actinic as you should go for a display that looks natural and appealing provided the inhabitants needs are being met first. Lighting output, spectrum, and intensity make a difference> However, in case I ever move up to SPS or whatever, I would also like to know what ratio of lighting I should use in this event. <Not a matter of ratio in my opinion as much as I believe that you have provided enough PAR for photosynthesis at the proper wattage output (intensity) and at the proper spectrum. Most high end aquarium lighting systems today, provide enough blue light at the 10000K spectrum for photosynthesis. Another important aspect to coral keeping is feeding. It is my belief that photosynthesis alone is not enough to keep corals alive. They are feeding at some level aside from photosynthesis.>  I cannot go MH as heat is an issue. <OK... Nothing can be made to mitigate the heat issue? Be sure you provide the proper environment before purchasing a particular animal or coral.> And, thanks for the great service you provide. <Thank you for your question. -Paul>  Cheers, Alastair

In The Dark...For Real! Well I don't quite understand Scott.. you mention actinics as a twilight.. well that is exactly what I have.. actinics are on at 10 am MH on at 12 noon MH OFF at 8pm actinics off at 10pm <Stupid me...too much late-night typing and not enough caffeine lead to an incomplete answer! Talk about "in the dark"! What I meant to suggest was to do a "twilight period", which you may want to gradually end with a dimmer or by shutting one of the actinics down at a time. I think that there are various controllers that you can get for Ice Cap ballasts that do offer such a feature. They can be pricey, though. In the interim, if you run multiple actinics, try shutting one off at a time over a period of 15-20 minutes or so...Hopefully that will let the fish adjust...> This undue stress is worrying me, as I don't want to see a single white spot cause that will freak me out, and annoy me like nothing else. As you may recall letting the tank fallow for 7 weeks, full 4 week stay in QT and everything else.. dips incoming and outgoing. <Good procedures that worked out well!> All these precautions only to see a fish stress is stressing me. Is there such thing as a dimmer, that will dim it slowly over say a few hours? (automatically) Anything I can do at all? Agh its annoying me.. <As above, I'd look into some of the aftermarket controllers made for Ice Cap ballasts, or look on the DIY sight OzReef to see if you can make such a dimmer that will work...> Did you read the last section of my previous message about the Tronic heater? <Didn't get that. But read your positive feedback on the attachment. Sounds like the Tronic heater may be a really reliable unit.> Attached below if you didn't. Cheers from down under Garth <Sorry for the confusion, Garth...Best of luck with the skittish tang...Scott F.>

PC Blues...Or Actinic Blues? Hello, <Hi there! Scott F. with you today!> I like to view the fluorescence on my corals, could you tell me which brand/manufacturer carries an actinic power compact (65W) that would provide the most fluorescence? <Hmm...no one particular brand delivers the "most fluorescence", However, things to look for in an "Actinic" bulb would be a bulb that peaks at 440 nanometers, which qualifies it as a "true actinic". There are a number of good "true actinic" pc bulbs out there. I've found the ones offered by hellolights.com to be of good quality, and they are "true" actinics. Coralife are good, as well.> I noticed that Coralife PC shows much more fluorescence than my current bulbs which are just a couple months old but I forget the brand. <Unfortunately, at least for the "aquarium hobby" end of the business, there seems to be no "standard" that manufacturers are held to...Quality and specifications can vary from brand to brand...> One manufacturer (I forget the name) promotes ultra actinic, does that necessarily mean more fluorescence? <Nope- it means extra marketing budget! I wouldn't take too much stock in advertising...Look for the stats on the bulbs, and let them guide your decision> 2nd question, My anchor coral which used to be brown and green is looking much less brown and almost clear and green now.  I have been experimenting with a couple of light bulbs lately.  What caused the brown color loss, will coral be ok, is there something I should do ? <Well, color changes are caused by the zooxanthellae and their response to lighting, of course. Under various PC lighting schemes, particularly those with heavier actinic/blue spectrum, I've noticed that Euphyllia take on a greenish clear color. As long as the coral appears healthy, and is otherwise well cared for, I'd enjoy the color! Thank you very much Thai <My pleasure, Thai! Good luck! Regards, Scott F>

Need for blue pc with 10K MH? 3/13/03 Hello there-       Thank you very much for your response.   <always welcome> Do you think that having all the actinics at the front of the tank will be a problem? Josh <not a problem at all... you'll notice less algae on the front glass too <G>. Almost every MH lamp on the market in fact have excess blue in their spectrum (including the 6500K lamps) and thus your pc.s really are not necessary to use at all... they are simply aesthetic. Anthony>

Actinic Lighting NO or VHO Hello WWM Crew! <whassup buttercup> Been a long time since I have written you guys. <indeed... I'm just getting out of therapy for it too <G>> My 75 Ga LPS, Soft, button and mushroom reef is going splendidly. <reef tank? That's not a reef tank... that's soup! Heehee... don't mind me... channeling Don Rickles today> Thanks to some of your advice a while ago. I mostly just pop on every once and awhile and read the posts. I want to upgrade my PC's to MH. (Calm down Bob) I love the look of MH's. To me that is the best looking light to be had. Crisp light, glimmer lines...Yeah baby, yeah! <easy there shag-master flash> Sorry. <very well... on with your question...> Will go with the PFO Hood with 2 175watt Ushio 10000K's and two fluorescent URI actinics. ( Yes Mr. Calfo, I will acclimate slowly) I know from long experience that actinics are really more for aesthetics as PAR is the most important ingredient. <correct> But... Gotta love the glow and the bluer color of the tank. <agreed> I can go with NO or VHO actinics. Would prefer NO for cost and electrical consumption but am afraid the MH's will completely drowned out the NO's light leaving only the dawn and dusk lighting to be enjoyed. What do you think? <either will be drowned out by the MH but the VHO will look better with the MH lights out> I know you may say it is overkill for my tank but have seen many others with far more wattage blazing over their tanks with great results. Two 175 watt singled ended shouldn't be considered outrageous. <agreed> I just gotta have the MH's. Tired of 25 years of Fluorescents. Tanks a lot. Zimmy <rock on my brother. Anthony>

More "Light" Conversation Hey Scott. <Whassup, Stevie Boi!> It's me again.......you know, .."Oh Good Lord not again with this guy"....me. <Hey- that's what people say about ME! :)  > I was cruising around the net trying to find out what the heck "Actinic" was, and found out that the term basically means "ray", as in ray of light. It seems that someone someplace, at one time or another, used the term to market a blue bulb they were selling.  I believe it was Philips. <Exactly, I think it first became popular in the mid eighties for aquarium use, and Philips was the manufacturer> Anyway, from what I am reading here and there, it seems that the phosphors in an actinic bulb are for mere "enhancement" of coloration of fish and corals, etc...... <Well- the actinic light does provide useful light for corals and other photosynthetic inverts. It provides spectral characteristics that correspond with the absorption of chlorophyll, which is the main photosynthetic pigment found in zooxanthellae (the symbiotic algae that live within corals). This, in turn, provides energy for the corals to use in their growth...So- actinic is more than just a pretty light!> So now I am confused because earlier on in my research I remember reading that the "actinic" bulbs were a necessary part of keeping invertebrates because the in order to respire, photosynthesize, live, etc. <Yikes- I just said the same thing, huh? I shoulda read your whole message instead of responding as I read huh? LOL> Am I incorrect in this? <Couldn't have said it better myself...In fact- I didn't say it better!> Here's the DEFINITION of "actinic" from WetWebMedia's dictionary: http://www.mv.com/users/besposito/definitions.html Actinic: A term used by many in our hobby to represent a blue fluorescent bulb. Originally blue bulbs called Actinic .03 bulbs were marketed by Philips. The blue bulbs appear to enhance the iridescent appearance of some corals. Currently, the term Actinic is used by many manufactures to represent their blue bulbs and I believe that rumors of special phosphors in the bulb are the urban legend. In actually, Actinic 03 as we know it was just a trade name and the actual definition of Actinic or Actinism is the "intrinsic property of radiation that produces photochemical activity." <Way too much time on your hands, dude! LOL> So .... are folks wasting their hard earned money buying these $20-$40 actinic specialty bulbs as additions onto an already existing metal halide lighting setup?, whereas basically the halide has enuf of the "blue" spectral light for micro algae/invert health...not to mention for corals, et. al. <No- I really don't think so. I believe that the value of actinics goes beyond just the beautiful appearance of animals that they help achieve. It really is a valuable and desirable supplement to many lighting schemes.> Just trying to clear things up before I take another Xanax. Thanks, Steve <I hear ya, bro! But seriously- I wouldn't feel too bad about including actinics in my lighting package. Good luck! Regards, Scott F>

Some Light Conversation! Hello gang, <Scott F. with you today!> It's me again. You've been most helpful in assisting me in the setup of my 55 gallon reef tank. from constructing a Durso standpipe, plumbing the filtration, to setting up my refugium, etc etc.  A BIG SHOUT OUT TO ALL !! <Thanks for the props, bro!> Ok....now that the brown nosing is over  :-) <Soo soon...? Darn! LOL> I have two 96 watt power compact fluorescents and a 250 watt Iwasaki Metal Halide lamp over my 55 gallon aquarium, with reflectors. The PC's are 50-50 daylight and actinic (twin tubes on each bulb, one blue one white  x 2 bulbs). With the addition of the halide lamp (6500 K), my tank took on a more white/yellowish hue, as to be expected with lamps in that Kelvin temperature range. So I went to www.hellolights.com in search of a blue/actinic type bulb to even out the coloration of the aquarium and provide more of a blue spectrum. I found that they had 96 watt PC's on clearance for $15/bulb (outrageous price for a 96 watt PC, regardless of the light intensity). <True!> Anyway, it stated the following about the bulb: * Factory liquidation!! We had a chance to get these at a true closeout price, and we're passing the savings on to you. One time buy on these. When we are out, we're out! * Lots of uses: back up bulbs in case your bulbs burnout, cheap refugium bulbs, algae scrubber bulbs, etc. At this price, it won't hurt to have a few spare compact fluorescent bulbs laying around! Please note, no returns or warranty on clearance items. * Faint "day actinic" looking bulb, simulates deeper water. If you light this up over your tank in complete darkness, it will look more blue than white in color. * These were part of a large custom order, and originally sold for over $45 a bulb! High quality, brand NEW bulbs for $15.00!!! * Nice 'faint white/blue light' if you are trying to keep any deepwater / lowlight animals like eels or octopus, this is an excellent bulb! * We must emphasize that this bulb looks faint compared to a 10,000K, Blue 7,100K or Actinic 03 bulb. * There seems to be a hint of actinic type fluorescing, but nothing major. * High quality, brand NEW bulbs!!! * Works in any standard Square Pin socket, 96W. My question is....I took off one of the PC 50/50's that had one blue/one white bulb on it, and replaced it with the clearance bulb from hellolights.com I fired it up and low and behold, a beautiful purple/blue light came on that really helped filter out that yellowish cast from the MH bulb. <Cool!> My question is this.  After you just read the description of the bulb above, do you now think that I will be lacking in the ACTINIC area, because this clearance bulb (according to the folks selling it), has a "faint actinic-type fluorescing". <Well, it sounds like it's just a visually "blue" light, so you probably are not going to get the results of actinics spectral output. Whether or not this is a problem depends on the type of animals that you are keeping, and their spectral "preferences">> So basically what I have now is the one 96watt 50-50 (daylight and actinic) PC, and one 96watt clearance blue "actinic like" bulb, and one 250 watt Iwasaki MH bulb. In your opinion, do you think with the mix of bulbs I have, that my inverts wont suffer due to lack of TRUE ACTINIC?, because I'm not sure what this clearance bulb's light intensity is.  I bought a bunch of em because the price was right, even as just a replacement bulb when the main one breaks or goes lame. <Well, again, it depends on the needs of your animals. If it wasn't for the pleasing aesthetics, many reef animals could be kept very happily with simple 6500K halides, with little or no "blue" supplementation. The problem with this, as you observed, is that it looks too darned yellow!> I've heard of people running 55 gallon reef systems with JUST Metal Halide lighting, and no actinics at all. <Yep> With MH's running, is there less of a need for Actinicbulbs?  Remember, I'm using a 6500 K MH which lacks some blue spectral light, but am not certain if blue spectrum is exclusively Actinic. <Well, some corals, such as Hydnophora, really like the actinic a lot, and do much better under heavier actinic regimens. Other animals tend to favor "warmer" daylight spectral regions. Regardless of the type of light source you are using (MH, VHO, PC's, or standard fluorescent, for that matter), the spectrum of the light is just as important as the intensity, in most cases, and should not be overlooked when selecting animals for your system. Metal halide bulbs of the wrong spectrum are probably less helpful to your animals than a standard fluorescent bulb of the correct spectrum for the animal! Yes- that's an exaggeration of sorts, but the basic premise is correct. For a lot of reasons, it's a good idea to supplement 6500ks with some "blue" spectrum, IMO> Maybe someone can clarify for me the difference between blue spectral light and actinic bulbs. <Well, in very rudimentary nutshell, actinic (which is essentially a "brand" name) light has a very specific spectral peak (440 nanometers). "Blue" bulbs, such as 20000k bulbs, come from the blue color temperature "range" of the spectrum. There is soo much information out there to review on the net that I'm really doing a disservice to you even trying to explain it so simply! Do look on the wetwebmedia.com site for some fine information on lighting, and do such on the 'net for the work of Sanjay Joshi, who has done a huge amount of experimentation with aquarium lighting. You'll really learn a lot!> Sorry so many questions, but I don't want to starve out the micro algae that the inverts need to survive. Regards, Steve <Steve- I think your questions are excellent, and that you will be doing a great job for your animals with your continued interest in meeting their specific needs! Good luck! Regards, Scott F>

55w Actinic light color variations? Anthony  The four Hamilton 55w Actinic bulbs that i used with a IceCap ballast, all 55w have a different color blue for each one. Have you ever seen this before?       RGibson <interesting, my friend. Will post on dailies to see if other aquarists have noticed this phenom. In their defense, it may not be much of a problem for coral... more aesthetics with a subtle variation in the acceptable range of actinic light (say 420-435 nanometers). However, on the other side of the token... I do not personally use or endorse this brand due to service/quality problems I have had with this company in the past and the unusual number of complaints I have heard from other aquarists in kind. They may be a very fine company in the big picture... I am simply content to take my business elsewhere.>

Re: Supplemental Actinic Lighting I (a newbie) currently have a 150 Watt, 10k MH unit on my 70 gallon reef tank. I find that my tank has a flat greenish hue to it. <hmmm... what brand here? I'm hoping you have a Ushio or Aqualine> I was considering adding an additional unit to bring out more of the blues and "correct" the current flat green effect. <tricky> I was thinking of using an actinic, but would like your thoughts. Thanks and HNY! <perhaps URI brand VHO blues... but if the MH is a wacky bulb for the purpose (Coralife, sunburst, Blueline, etc) you may want a more attractive MH lamp instead.>

Lighting Hello! I have a 75 gallon reef tank with 440 watts of PC lighting. I am not real happy with the blue actinics because they seem more blue/aqua color than purple. <A common complaint with the early PC actinics.> My corals seem very brownish and not really what their true colors are. With PC lighting, I realize there is blue actinics and 03 blue actinics. Do you have any experience with 03 blue actinics for PCs vs. regular blue? <No personal experience, although I have seen both.> Would this make a big difference as far as increasing the purple color and drawing out more color of my corals? <Yes, the true actinic 03 lamps are much better than the first blue PC lamps.> The reason I ask is because I was told PC actinics don't come close to VHO actinics. <I would have said the same thing before. Now, I think they are much closer.> Right now, I am using 10,000K as my whites. Would it be more helpful to reduce my whites to 6,500K as well as increase the actinics to 03's? <6,500K is a yellower color versus 10,000K. Although, I like 6,500K lamps not everyone does. Regardless, definitely get the true actinic 03 lamps. I am sure these will make you much happier.> When I bought this light kit, 3 months ago, I was considering a VHO light kit and consulted your web page. I was told PC lights are more economical and generate less heat than VHO. <They are probably cheaper to run, a little less watts per useable light energy and a long life on the lamps.> But I am not sure I if the colors I am getting was worth it. I really can't believe it but I am considering going with a VHO kit and selling my PC kit. <I would not do this.> I was also told that PC's don't penetrate the water as well as VHO's. <I believe them to be about the same in this regard.> Please let me know what you think. Thanks, Ronald <You are welcome. -Steven Pro>

Lighting Hi everyone, Bryan Here. <Good day sir! Hope you are having a pleasant holiday weekend.> Question about lighting for reef tanks. I have a 75 gallon that I am thinking about keeping some soft corals since I am a beginner in reef setup. Looking at about 260 total watts of lighting, still not complete because I am still researching and haven't decided exactly what I want to add. My question is this, I have been looking at the 48" JBJ Power Compacts. I have read somewhere though that VHO can give a more blue/fluorescent look and the corals really stand out. <IME, VHO actinics are superior to PC blue lighting. There are supposedly better PC actinics on the market now.> I personally like the blue look and was wondering if this is true (about VHO). And if so, can the power compacts give off a more blue with the right bulbs? <Yes, perhaps now with true PC actinics on the market.> Last question is, do you want/or is it healthy for the tank to have a more bluish feel/look with the corals. <It really depends on the corals. Deep water LPS corals do benefit from actinic lighting, but it can be of little benefit to shallow water corals. All things in moderation and you should be ok. No more than 50% of your lighting in actinic for deep water corals and closer to 25% maximum for shallow water species.> Thanks for all your help. <You are welcome. -Steven Pro>

Actinic Blue Lights Hi-I was hoping you could answer a question(s) for me. I have eight 65 watt compact fluorescent bulbs for my 125gal fowler. The light retro fit kits came with 4 actinic blues and four 8800k daylights. <OK> In your opinion would it be better to use less blues and more daylights? Maybe 2 blues and 6 daylights? Four blues just seems like a lot. <I agree> Also, can the actinic blue bulbs (shift spectrum)? when they are old and encourage the growth of red algae? Or do just the daylights do this? <essentially the daylights> Thank you again, Dennis <our pleasure! Anthony>

Actinic lighting on/off hello again...I would like to get your opinion on a question I have. I currently stagger the on/off of 2 sets of VHO bulbs by turning the actinics on an hour before and off an hour after the full spectrum bulbs. <traditional> recently I have read a few things that suggest doing this the other way around. they claim that at the depth most commonly kept marine life naturally occurs, the blue spectrum is most present at midday. <blue light penetrates the deepest> does this make any sense?  <fuzzy logic> if so is there some documentation or research you can refer me to? <no idea, my friend... but all is moot. It is all and only a matter of aesthetics. Without dimmer/phase on timers anything you do is an unnatural slam-on of lighting. The animals adapt regardless. I would continue as you have been doing> I am also curious about introducing a small incandescent light at night. is there any benefit to simulating lunar cycles and is an incandescent light the best way to go about this? <I believe so very much... I wrote a piece on this topic in my Book of Coral Propagation with an illustration for making a dimmer switch template to follow lunar cycles. Some aquarists rig up elaborate microprocessors to wax and wane a blue light. All good and natural for fishes in particular, I believe... especially for spawning fishes> Thanks for your help once again. Jeremy <best regards, Anthony>

Color Spectrum VS Color Temperature (lighting a 2' deep tank, mix of invertebrates...) Bob, <Steven Pro in this afternoon.> I have a 180 gallon fish/coral setup and I am getting varying opinions on lighting recommendations. I house soft corals only: leathers, mushrooms, and anemones, and need proper lighting for them. Currently I have two power compact systems a four foot retrofit (including two 22" 65 watt Ultra-Actinic and two 22" 65 watt 6700K Ultra-Daylight bulbs) and a six foot retrofit (including two 34" 65 watt Ultra-Actinic and two 34" 96 watt 6700K Ultra-Daylight bulbs), total of eight power compacts. My first question is which is more important to these corals color spectrum or the color temperature? <The most important factor is intensity, then spectrum.> Second question is should I have more actinic lighting or higher color temperatures to keep the corals healthy and growing? <Full-spectrum/daylight lighting is best for corals with some actinic lighting for appearance sake.> Third question is do the reef critters see blue light as high noon? <That is not my understanding.> Should the bright daylight bulbs come on first and go off last while the blue bulbs come on second and go off first? <Most people run there tanks the other way around, actinics first to come on and last to go off.> Thanks, Dave <You are welcome. -Steven Pro>

Color Spectrum VS Color Temperature II Steven, Thanks for the quick response and answering all of my questions. My reason for asking the third question was that I obtained some information from the Pet Solutions' (mail order company) web sight that I wasn't to sure of "To the reef critters, blue light is high noon, so actinic bulbs really should not be used to simulate a sunrise/sunset with other daylight bulbs. The "bright" daylight bulbs should come on first, then the actinic." I always use to have my blues come on first and go off last, as well, until I read this article. Take a look at their web site to see for yourself if you're interested. The information is located in their Reference section under Diving Deeper - Lighting Basics For Mini Reefs. <I found and took a quick read through the article. It does not say much more than your quote. First, most white-appearing lamps for reef aquariums have a lot of blue white in them, many the same as full actinic lamps. It is just that they have a lot of other color spectrums too which gives them an overall appearance of white light. Take the example of the 6,500 K Iwasaki MH lamps. No one is going to say they appear blue, more likely yellow/green, but they have a substantial amount of blue spectrum light and are quite capable of growing thriving corals without any supplemental lighting, although the appearance and fluorescence of the corals will not be the same. Secondly, most aquaria are so shallow you are not going to get a lot of blocking out of the other color spectrums. I think it is at 10 or 20 meters that all of the other spectrums have been completely blocked out. That is a lot deeper than any aquarium I have ever seen. Now many of our aquariums are not as clear as open ocean water, but still. Lastly, waxing and waning is nice, but not absolutely necessary and you could probably wax and wane whichever with the same effect.> Thanks, Dave <You are welcome. -Steven Pro>

Lighting Question Sorry to bother you again guys <No bother, what we are here for.> just wondering what the downside to having too many Actinics on a reef tank? <Actinics add fluorescence to the tank lighting and simulate deep water lighting.> I have a 96 watt compact florescent and four 95 watt VHO Actinics.... I want to replace 2 of the actinics with 10,000k VHO's just wondering what your thought are on this. It's for a 125 gallon tank. Here is some of the preliminary pictures too <I think it would be a good idea. From the looks of it, you house mostly LPS's and soft corals. I generally use a 50/50 mix of actinics and full-spectrum lamps for these animals. Two VHO actinics, two VHO 10,000K's, and a PC full-spectrum sounds good.> Thanks, Scott Allen <You are welcome. -Steven Pro>

Actinic lights...White or Blue? I have a 65 gal reef tank set up and I have MH/Actinic combination lighting on it.  <nice combo my friend> It is about time to change out the fluorescents and I was wondering what exactly the difference is between regular blue actinics and actinic whites?  <marketing and a wheelbarrow full of crap. Actinic Whites are excellent bulbs (I love URI brand)...but they have nothing to due with the blue actinic wavelength or the price of tea in China. You have enough daylight in your MH bulbs I presume. Replace blue with blues (again...I like URI brand very much> Would it change my tank or corals at all? <some for better, some for worse perhaps. Do you have mostly shallow water SPS species? If so, maybe the extra white would be nice. But you will no longer be able to turn off the MH bulbs, leave the straight blues on and turn on Pink Floyd music> Any input would be greatly valued! <stay with the regular blues to compliment your MHs> Thanks! <quite welcome, Anthony Calfo>

03 Actinic PC Hello Mr. Fenner, <Good evening> I am sure you have covered this but I did a search to no avail. I have JBJ PC lights, 110 watts, on a 29 gallon tank. I have been reading up on the new 03 actinic pc bulbs and wonder if they are really different than the blue, being they both are rated at 420 nm. I would appreciate it if you could shed a bit of light on the question. <Okay for the pun... they are ostensibly and functionally the same. Bob Fenner> Thanks, Josh

Shop lights I have a problem. I would like to buy some 48'' shop lights. People have told me that actinic 50/50 bulbs burn out faster in these lights than in aquarium manufactured ones. I hope to use these in a reef aquarium. Will they give me enough light? Any info. at all will be very helpful. Thank you in advance. <Hmm, actually "they" burn out about the same rate... and in any length cost less considering the savings on the fixtures... And "enough light" for what sorts of organisms, purpose, size/shape tank? Bob Fenner>

Lighting for FOWLR thanks again for your response to my last few questions... <You're welcome> I have a 125 gal (60X18X24) FOWLR with Amiracle sr200 w/d, Turboflotor t1000 skimmer, two Rio 1100 powerheads, about 100 lbs live rock...I plan to retrofit the existing hoods --two 24 inch abs--with power compacts by custom sea life. they offer a choice of two 65 watt pc's: one ultra-actinic, and either one of 8800K OR 10000K ultra daylight. I may convert to a full reef in about a year or so...which ultra daylight bulb should I buy now, the 8800 or the 10000K? <Hmm, either one will do... the 10K is a bit bright/white for some taste, but would be my choice for functionality> what advantages/disadvantages does each bulb have over the other. Is this lighting way too overkill for a FOWLR system? <Not too much overkill, no real yes/no advantages... the higher Kelvin rating indicates an ability to penetrate deeper/with more intensity... a small degree of difference. Bob Fenner> thanks again for your advice, Knef

Aquarium Lighting Question  Bob, you are indeed helping... most everyone I know who questions the PC Actinic lamp talks about their color... compared to a Coralife or URI lamp... They say the PC Actinic closely resembles a lamp called ?Marine-Glo? by Hagen and not a true Actinic 03 lamp. So, I will be talking to you soon. It is great to have someone consistently return e-mails.  Thanks, Terry  <Glad to be here... am a bit quizzical about the fact and why other folks should find these lamps color differences remarkable... both types "work"... i.e. produce light in "actinism" wavelengths... they just have slightly, but perceptible appearances from slightly different mixes of visible (to humans) wavelength mixes. Bob Fenner>

Aquarium Lighting Question  Hello Bob,  As you can see below, you answered a question of mine a while back... I hope you can help me with this one. 58 gal tank... had two NO URI lamps (Actinic 03 and 6700K bulb... 30 watts per lamp) on my tank. I purchased a PC lighting system with one 6700K and on Actinic (7100K). The PC Actinic lamp has a light blue color and my URI lamp has a deeper purple color. The URI lamp may be 8000K I think...  the PC bulb is 7100K... both peaking around 420nms. Is my new PC Actinic a true Actinic bulb?  <Yes> Is it better than my URI Actinic lamp? <Yes... in terms of the cost per energy consumption, service factor (replacement rate)... overall useful energy per dollar> Does the color have anything to do with its effectiveness? <Marginally... Not appreciably> The company I purchased the lighting system from said the PC lamp is a better, more intense lamp.  <Yes, more useful photonic energy... less cost per unit to produce...> Could you help?  Thanks, Terry <Be chatting my friend. Bob Fenner>

Aquarium Lighting Question  Bob, Thanks for the response... So, you would be comfortable with a PC Actinic lamp? <Absolutely. This would be/is my first choice in formats (currently!)> A few people warn me that the PC lamp, because of the color, will not keep my inhabitants happy and healthy. <What? Nah... the color means nothing to your inhabitants> Also, would different brands of PC Actinic lamps display a different color... for example, Coralife by ESU?  <Hmm, well, by the real manufacturers, yes... as you'll find, these lamps are just relabeled/sold/distributed as/by OEM's... not that many real makers... so not that many real discernible differences in the working of their lamps> Why would my NO URI Actinic lamp have a darker, purple color and the PC  Actinic have a blue color?  <Mix, blend of other apparent wavelengths of light, variances in the glass of the batch/manufacture...>  Especially if they are suppose to be the same spectrum? <These products have a stated "target" wavelength, but do indeed have differing spectral composition... a blend of other wavelengths... You can buy, borrow or visit a lab/college and test for this yourself... along with issues like intensity and energy consumption per...> Thanks so much for the help. Terry  <Hmm, not so sure I'm helping here... look into light meters on the Internet... and we'll be chatting. Bob Fenner> 

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