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FAQs about Fluorescent Light and Lighting for Marine Systems, Fixture Selection

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Watts per gallon... is a very slippery measure of how much "light" is necessary, desirable... Real quanta of use-able spectra, ones goals (growth, color, reproduction, maintenance), and costs fixturing, power... all need to be taken into consideration.

I've been told that you can use VHO fluorescents on tanks up to about 24"deep, but more than that you need metal halides. Does it go the other way, too? I mean, if you have a tank that is only 12" tall, can you use regular full-spectrum fluorescents and still have a successful reef? To a large degree yes; though an answer to this sort of query must delve into a few statements of fact, definitions and qualifiers to be of real use. First, let's agree that the intensity of light (number or quanta of photons) is the principal difference between full-spectrum fluorescents (FSF) and metal halide (MH) lighting sources. That is, both types produce adequate amounts of light in necessary and desirable (function and aesthetic) wavelengths to support and showcase captive reef life. MH is more intense, and thus able to penetrate to greater depths and provides more light to shallow ones. Whether this is critical or something you want though depends on two further major considerations: the type of life you intend to keep, and how much you want to "push" it. In aquariums as in the wild, there is a broad range of benefit and tolerance to more light. For example, Corallimorpharians (coral anemones), most of the photosynthetic gorgonians and soft corals (Order Alcyonacea) available to hobbyists get along quite well on FSF and compact fluorescents (CF) in the deepest of hobby aquariums. On the other hand, several of the popular true or stony corals (Order Scleractinia), do poorly unless provided either a roost in a shallower setting (with FSF, CF), or MH in greater depths. The "pushing" issue is a consideration of how much you want to enhance your organisms metabolic rates. Lighting, along with nutrient availability, conscientious filtration, and current are principal inputs to this physiological "driving". Do you want your Acropora for instance to grow about as fast as possible? Maybe it will become more spindly, less colorful, more short-lived as a consequence... Perhaps the cost of water testing, dosing and amelioration is only "worth it" up to a point. Each aquarist must ask themselves this question; "Per the species/specimen and environmental settings, what do I want my livestock to do?"| Obviously all light-affected life needs to be accommodated within its environmental tolerance; hence you must study and provide at least the minimum or at most the maximum amounts of light per that species/specimen in your setting. Such information is invaluable, and often more than just a matter of reading and chatting with other reef hobbyists and dealers. A tried and true approach for new introductions is initially placing them further down or away from the most intense light area, and moving them "toward the light" as they display a propensity for it. One last element of this "how much light will do/is too much" question I'd feel remiss to leave out is the effects of dissolved (mainly colored) material in the systems water. The cleanest of seawater absorbs, reflects and diffracts light; more and more with depth. The presence of suspended solids and various chemicals has an additional, often pronounced effect on diminishing photo strength. In practical terms, and for more than light penetration reasons, you want to keep concentrations of this matter to a minimum; principally through skimming, water changes and possibly the use of chemical filtrants. This is an area of discussion that merits much more emphasis and investigation.

Lighting/Duro-Test Vita Lite 10/3/09
Dear Mr. Fenner
<James with you today.>
I recently read an article you wrote about lighting where you gave your full endorsement to the Duro-Test Vita-Lite full spectrum light as the best overall useful light for an aquarium. I wanted to know since the writing of that article if you still consider this the best type of useful light or have newer technologies and higher Kelvins become the new recommended way to go?
<Frank, I'm thinking that article was written shortly after the Romans scrapped their chariots for a better ride (no offense, Bob).
<Et tu James? RMF>
 The newer technologies, T5's, PC's, HQI, etc., along with the wide Kelvin range available, is definitely the way to go. Although the Duro-Test lamp is a decent lamp, rendering a CRI of 91, and a Kelvin temperature of 5500K, it is not available in T5 or PC format, T8 being the best they deliver with this lamp. Best to go with the high output/high efficiency systems.>
<Cheers, James (Salty Dog)>
Frank H.

Re Lighting/Duro-Test Vita Lite 10/3/09
Yes Bob, can understand Et tu. I was likely riding along side of you, only a little further back.
<Maybe a side car?>
Nothing like a little humor to break up the dailies routine.
<I'll say!>
<And you my friend. B>

Lighting Question (PC v. T5) 8/15/09
Good day,
Thank you for the wealth of information on your website. I am new to reef aquariums and I made some initial mistakes your website is helping me correct and others it has helped me avoid.
<We're glad you are making good use of it.>
The system was given to me and I am working with my current specs and upgrading as money and time allow.
I have read through the entire section (3 of them actually) and I still am left a bit confused on lighting.
<There are a lot of options.>
Here are the specs of my system:
35g bow front (12D X 32W X 24H)
40 pounds of live rock
2 inches of live sand
Deluxe Red Sea Prizm Skimmer
Fluval Canister Filter
2 400gph powerheads
5 Hermit crabs, 5 snails, TR Percula Clown, Red Scooter Blenny, Fire Goby, Blue Green Chrome, 2 Shrimp (Fire Red and Cleaner)
Mostly soft corals (clove polyps, mushrooms, white xenia, Xenia and Zoanthids). I also have a purple tip frogspawn.
My current lighting system is a PC with one bulb (it is actually a dual bulb, one blue and one white; 10,000K/460nm). It began to flicker so I removed it and am currently borrowing a friends TEK T5 lighting system (4 24" bulbs - Pink, Blue and two whites) while I determine the best system to purchase.
I would like to add some SPS (like the Montipora capricornis) and another LPS (a branched hammer).
The tank has a hood that limits the size (only about 4" deep) of a fixture and makes heat a potential problem...this seems to rule out MH lamps.
As I look on your website, talk to guys in my local reef society and LFS owners I get more and more confused as to what my lighting needs are. The responses are so dogmatic and diverse it makes the whole thing sound like a preferential choice. It seems the needs of the different species are too specific to leave it up to preference
<Likely most of the species you want to keep can be kept under T5 lighting.>
Given the limitations of my hood size (and my wallet) I seemed to be left with a couple of options; (I am happy to restrict my species purchases for the sake of staying in my current set up)
1) Upgrade my PC's to a dual bulb system and possibly get my other PC fixture fixed and add it as a third, dual bulb)
2) There are small T5 set ups by companies such as Current (i.e - the Nova Extreme) but the wattage is much smaller and I am not sure any improvement over what I currently have.
<I would recommend T5's.>
3) Something altogether different I have yet to discover.
<However, please consider a T5 Retrofit kit with individual reflectors as an alternative to T5 fixtures. It will be much less expensive, more effective, and generally smaller inside the hood.>
The only other livestock considerations (as I sneak in extra questions). Would this lighting system sustain the same tank if I switched to anemones from the corals down the line? And is it bad husbandry to purchase a fish too small for my current tank (a sand sifting goby like the diamond goby) to allow it to work on my tank until it grows and then give it away via a local reef forum to someone with a bigger tank?
<I would say that is bad practice, they are also surprisingly hard to remove from an established tank.>
Sorry for the length of this. I wanted to make sure I gave all the pertinent information though I am sure I have left much out.<You did fine.>
This has already proved to be a wonderful hobby but with a huge learning curve. Thank you for your help and patience with beginners.
<You are welcome, Josh Solomon.>

Lighting T5 vs. PC -- 02/14/09 Hi Bob, <<EricR here>> I have a question concerning a lighting choice for a 65 gallon reef tank. <<Okay>> I spent a lot of time on WWM and designed a really nice 45 gallon sump / refugium from acrylic and I also learned a lot from past mistakes. <<Excellent'¦good to know>> I don't want metal halide and I am torn between ATI T5 6x39 watt Sunpower fixture $479.00 or going with 4x96 watt pc's. <<Depends on what you 'need''¦the PC fixture will be measurably brighter/more intense than the T5 fixture (384 watts vs. 234 watts), assuming similar Kelvin ratings of the bulbs selected'¦but likely either 'will do'>> I don't have the need to keep sps, but I am very confused about T5. A lot of people say T5 is better, but when I ask if they use them they say no. <<Just differing technologies'¦ The T5s are sleeker, more modern looking, and seem to have a wider selection of bulbs/Kelvin ratings available'¦and with the excellent reflectors available for them, when used, they do seem to have an edge on output over the PCs>> The Sunpower T5 fixture has active cooling and high-end reflectors. Can this produce equal or more light/par? <<Watt for watt'¦it can, yes. But I don't think there is any way 234 watts of T5 lighting is going to out-produce 384 watts of PC lighting'¦as long as both are using bulbs of the same Kelvin>> I understand restrike from pc's and I just want some feed back from a smart person. <<I honestly don't know just how much light is lost from 'restrike' between the legs of PC bulbs'¦but of the two units you have listed here, I'm fairly confident the PC fixture will provide the most output due to its significantly greater wattage'¦again, assuming similar color temperature among the bulbs in the two units>> Thanks for your help. Sap81352 <<Happy to share. EricR>>

Lighting Question, fluorescent clas., use comp.   2/10/09 Hello Crew, <Hello Matt, Minh at your service.> I have a very simple question for you today. I currently have a standard 55 gal tank with some mushrooms and polyps and about 60 lbs of live rock. I am currently running a 2x55 watt power compact fixture. I really want to start keeping many types of corals in my tank so I feel that I need to upgrade my lighting. I was thinking about getting a 4x65 compact fixture. My question is, is there a difference between power compact lighting and compact fluorescent lighting? <No, they are one and the same.> Sorry for the lame question, but I am seeing both of these listed and see no difference between them. Also, does the lighting upgrade above seem to be good enough? One more thing, what about the T5 fixtures that are out there? <Although 4x65W PC/CF fixture is an improvement over your current lighting set up, the better alternative is High Output T5 (or T5 HO) lighting. T5 HO lighting runs cooler, lasts longer, and has a better wattage/intensity ratio than PC/CF lighting. More information can be found here: http://tfivetesting.googlepages.com/.> Thanks for your help Matt <You're welcome. Cheers, Minh Huynh.>

Re: Lighting Question, fluor. f'    2/11/09 Thanks for the quick response. I have one more quick question for you today. Should I consider MH lighting as an option. I love how it looks but I have read concerns about the heat. My tank is an open top and I do not want to overheat the water. If MH is an option, can I place a 36" fixture over my 48" tank to save some money or do I need the 48" fixture? <A 36" MH fixture would work on a 48" long tank. However, consider that MH is a single point light source and as a result, the sides of the tank will be dim. This could be a positive in the sense that it will create a sense of depth and also allow you to set low light corals in these areas.> Also, what type of wattage should I have in the MH if I decide to go that way? <The type of MH bulb is more important than the wattage of the set up. For example, a 175W Iwasaki 15k bulb has more intensity than some 250W bulbs and even some 400W bulbs. Take a look at this site for some intensity data on most popular bulbs: http://www.manhattanreefs.com/lighting.> Thanks Matt <You're welcome. Cheers, Minh Huynh.>

Re: Lighting Question, T 5...    2/11/09 Say I decide to go with the t5 lighting, would it be too much light for the 6x54 watt or should I use the 4x54 watt? <This would depend on the type of T5 lighting you chose. Certain setups, with high performance ballasts, reflectors and bulbs can be extremely bright and 6x54W could be overpowering and push some corals into over-saturation and photo-inhibition. If you intend to keep mostly soft corals and LPS, most proper 4x54W T5 HO set ups would be more than sufficient. For SPS and/or anemones that require more intensity, 6x54W would be a better choice. For reviews on the most common T5 lighting fixtures, go to this site: http://tfivetesting.googlepages.com/.> Matthew Diethorn <Good luck, Minh Huynh.>

Re: Stocking, Questions in general, reef  11/17/08 Scott, Thanks again for your help. <Welcome.> Just one more question. What I'm looking to do is add frogspawn, torch, or hammer corals to my tank. Do you think the lighting I have now would be efficient, if the coral is about 12" from the light, or should I replace the Coralife t-5 with another dual 55watt t-5 light, giving me a total of 220 watts? <If adding light is an option, I would. What you have is on the low end as it stands.> And would this be efficient for this type of LPS? <Yes.> Thanks again, I did read through the FAQs, but it seems a little dated, not much about t-5s, and the ones that do, aren't the same tank size, or are stocking different corals. Marc <Welcome, Scott V.>

Comment on Light Posting, fluo. fixt. choices  11/18/08 Dear Scott, <Hello again Andy.> I was reading Today's Questions and saw a snippet of a post about the TEK vs. Aquactinics lights. Unfortunately, I couldn't find the original post/answer, so forgive me if I'm way off base here. The post/answer was: "Re: Lighting for 55 gallon reef 11/16/08 Thanks Scott. <Welcome.> With bulbs and all, they were very close in price. It seemed that the Tek light was the better deal, but with the Aquactinic rep I wanted to make sure I wasn't missing something. <Nah, same basic thing except the extra bulb.> dean <Scott V.>" I assume the poster/you were talking about the TEK 6 light HO T5 versus the Aquactinics TX5 fixture? <Yes.> I have seen/observed both of these in action, and I can tell you that there is a pretty significant difference between the two fixtures, IMO. The difference in output/light quality/brightness is pretty astounding, with the Aquactinics being the superior fixture. I'm not poo pooing the TEK, which is a fine fixture, but the 5-bulb Aquactinics I've seen produces a much better/brighter output than the 6-bulb TEK. Maybe it's the reflectors, maybe it's the ballasts, maybe it's the bulbs that were being used--I don't know. I've been told that the TEK runs very hot, which I'm also told reduces the efficiency of the fixture/bulbs. Although I don't always subscribe to this way of thinking, I honestly believe there is a reason the Aquactinics fixture is more expensive--because it is hands down a better fixture. My LFS uses both, and the difference really is impressive. I'm sure you/others have a lot more experience with light fixtures, and maybe these models in particular, but I just thought I'd share my impressions/$.02. <Thank you for your input, I do have to say I myself have not seen the difference. There are so many factors to consider: bulb type/spectrum, age of bulbs, fixture maintenance (reflector cleaning), and even the perception of light put out. Both of these fixtures use HO T5 bulbs with individual reflectors. I do appreciate your comments and this will be posted for others to make a more educated choice. Thank you.> Andy <Talk again soon, Scott V.>

Re: Lighting for 55 gallon reef Further Comment on Light Posting, fluo. fixt. choices 11/18/08 Hey, <Hello Dean.> I was reading the dailies and saw a response to my post. I have comment of my own. <Okay.> Scott and Andy, I did choose to go with the Tek 6 HO light for a couple of reasons. I agree that the Aquactinics TX5 has some performance characteristics over the Tek 6 Light, but the Tek 6 has some as well. The Aquactinics has better reflectors and active cooling, and both contribute to the fixtures performance. From my research, the TX5 can penetrate better. My tank however is only 20" deep, with a DSB also in the mix, so I cannot take full advantage of the reflectors. If my tank was a 65, 36x18x24 it would be a different story. As for active cooling, I saw my third snowstorm of the season today, My place doesn't get that warm, and I can always add a fan. In the end what was the deciding factor was the sixth bulb. Not because extra wattage, but because a sixth bulb give me more flexibility in mixing bulbs and tuning the spectra. <A good point not yet mentioned.> My bulbs are: Back ATI Blue Plus ATI Korallin Zucht Fiji Purple Giesemann Midday ATI Blue Plus UVL 72.25 ATI Blue Plus Front The TX5 may be the better fixture, but the Tek 6 made more sense in my situation as it turns out. I would have had to give up my 75.25 and I really wanted that to pull out the reds in my firefish and coralline. But thanks for the help! This has been very educational for me. Y'all rock. Dean <Thank you for the further input Dean. My stance re has already been posted. Glad you are happy with your choice. Scott V.> The post was: *Comment on Light Posting, fluo. fixt. choices 11/18/08* <Hello again Andy.> I was reading Today's Questions and saw a snippet of a post about the TEK vs. Aquactinics lights. Unfortunately, I couldn't find the original post/answer, so forgive me if I'm way off base here. The post/answer was: "Re: Lighting for 55 gallon reef 11/16/08 Thanks Scott. <Welcome.> With bulbs and all, they were very close in price. It seemed that the Tek light was the better deal, but with the Aquactinic rep I wanted to make sure I wasn't missing something. <Nah, same basic thing except the extra bulb.> dean <Scott V.>" I assume the poster/you were talking about the TEK 6 light HO T5 versus the Aquactinics TX5 fixture? <Yes.> I have seen/observed both of these in action, and I can tell you that there is a pretty significant difference between the two fixtures, IMO. The difference in output/light quality/brightness is pretty astounding, with the Aquactinics being the superior fixture. I'm not poo pooing the TEK, which is a fine fixture, but the 5-bulb Aquactinics I've seen produces a much better/brighter output than the 6-bulb TEK. Maybe it's the reflectors, maybe it's the ballasts, maybe it's the bulbs that were being used--I don't know. I've been told that the TEK runs very hot, which I'm also told reduces the efficiency of the fixture/bulbs. Although I don't always subscribe to this way of thinking, I honestly believe there is a reason the Aquactinics fixture is more expensive--because it is hands down a better fixture. My LFS uses both, and the difference really is impressive. I'm sure you/others have a lot more experience with light fixtures, and maybe these models in particular, but I just thought I'd share my impressions/$.02. <Thank you for your input, I do have to say I myself have not seen the difference. There are so many factors to consider: bulb type/spectrum, age of bulbs, fixture maintenance (reflector cleaning), and even the perception of light put out. Both of these fixtures use HO T5 bulbs with individual reflectors. I do appreciate your comments and this will be posted for others to make a more educated choice. Thank you.> Andy <Talk again soon, Scott V.>

Mercury/CF Lamps -- 07/14/08 Hi Bob, Am wondering how many aquarists are aware of the higher mercury content of Compact Fluorescent and T5 lamps. <Doubtful many> One T5 lamp contains 3mg of mercury and Compact Fluorescents even more. As you know, mercury is a potent neurotoxin and handling these lamps should be done with care to avoid breakage which leads to mercury contamination of the area. There are some states that have made it illegal to dispose of these lamps in normal trash pickup...they must be recycled. Have a nice day, James (Salty) <... Will post, share... B>

Aesthetic Fluorescent Supplementation, Marine Tank   03/23/07 Howdy Crew, quick one for you. <Hello.> I am running 2, 250 HQI 14.5K bulbs on my reef tank, but I don't get the "pop" colorwise without running actinics. <They are "neat" looking....and yes neat is a scientific term....maybe.> Could I get away with adding 2 standard 40W actinics with a reflector? <It's just for color/aesthetics so yes...won't hurt anything.> Will they make a difference visually, even though they only total 80 watts?   <Visually yes, but as you know they won't make a difference par rating wise.> I do have VHO's but I really don't want to use them since its wastes more electricity and generates extra heat, not good. <I understand.> What are you opinions. <N.O. fluorescents are fine, but you can also look into T-5's, and not just the high output versions either but the normal output as well...they are low wattage, don't impart much heat onto the water.>   Thank you for your time.   <Of course.> Paul <Adam J.>

Overdriven fluorescents and anemones -- 03/17/07 Hello. <Hello Mark, Brandon here tonight.> I have a long tentacle anemone, probably a Macrodactyla doreensis, but possibly a Heteractis crispa in a 30 gallon tank with two small maroon clowns and a couple of torch corals. <For either of these species of Anemone this is too small a volume.  Please consider an upgrade.> Water quality is good, except for 2-4 ppm nitrates.  I've had the anemone for six weeks, and after staying put in the first month it's now  taken up wandering aimlessly. I fear for the corals and worry about the anemone's well-being. <This is common with all anemones.  It is recommended to never place an Anemone with other Cnidarians.> Might the lighting be a problem? <This is always a good possibility.> I have four 20 watt NO, two 10000K and two actinic, all of them 2X overdriven.  I haven't been able to find anything definitive about light output from overdriven NO vs. compact fluorescents. <I will be honest with you, I would not keep an Anemone of any sort under PC or overdriven NO.  The minimum I would use would be four, four foot 110 watt VHO lights.  Two Actinic 03, two Full Spectrum 10000k.  Better still, (and what I currently use) would be HQI double ended 10k MH.  All of this is rather dependant on the size of your tank.  I will assume that you have a normal 100 gallon (by this I mean rectangular.)  In this instance I would use one 150 watt HQI MH fixture.> Just from eyeballing, it looks like I get the same light output per watt from both, so I'm guessing my 80 watts 2X overdriven is about the same as 140-160 watts from compact fluorescents. Is that adequate, do you think? <You can't guess by eyeballing.  Light levels can be deceiving from outside the tank.  The only sure way to tell is with a Lux Meter.  But at a guess, no it is not the same, and I would not think with the Anemone moving like this, that the light is adequate.  Additionally with the overdriven NO's you will have a very short bulb life, say one - four months, as opposed to six - a year with the PC's or MH.  Please do some reading here, http://www.wetwebmedia.com/marlgtganthony.htm.> On the assumption that its a doreensis, I've had it on the sand bed, 3-4 inches deep, with live rock surrounding a bare area 2-3 inches in diameter. According to the usually reliable LFS,  it will dig its base into the sand and probably attach itself to a buried rock. Is that true? <It should dig into the sand yes.  It would help if you could send a picture, as this will lend to a positive ID.> It doesn't seem inclined to attach itself to a rock anywhere. There is a nook currently occupied by a torch at the top of the aquarium. Might it be worth a try moving the coral and putting the anemone there? <I would not move it.  It will go where it wants to.  Right now it is looking for an area that suits it's needs and is not finding one.  I would seriously look at upgrading my lighting in the next few days or so.  If you decide to go higher in output do try to slowly acclimate your critters using a piece of screen over the top of the glass or a shortened light period.  Much more on this on WWM.> How likely is a doreensis or a crispa to attach itself to rock, as opposed to substrate? <See above Re: picture.> Thanks so much. Without  forums like WetWebMedia, I don't think reef aquaria would exist, even with the hardware and technology of the last decade. <Thank you for the kind words.  I am proud to be a part of an organization that allows this much free exchange of ideas and information like this.> It means an awful lot to me that at the end of the day I can leave the rat race and chill for a bit with a hundred gallons of Nature and beauty. Sort of gets me centered again. <Agreed.  Good luck with this.  Please try to send an image.  Brandon.> Mark

Re: Stacking fluorescent lighting 12/20/03 Crew, First off, a big thanks: WWM and TCMA have been indispensable sources of  information.   <Glad to hear you have benefited!> I'm researching possible lighting solutions for a 120 gal reef tank.  I'd like to keep tridacnid clams (derasa, gigas or Squamosa) and compatible soft corals. <The clams that you listed are the least light demanding, so read on for what will probably be a pleasantly surprising solution to your dilemma.> Is it possible to stack fluorescent lamps within a canopy?  (provided I solve ventilation and lamp support issues)  I am assuming this isn't  advisable since I've only seen canopies that feature lamps flat on a single plane parallel to the water's surface. <Stacking the lamps will lead to almost no additional light reaching the animals in the tank.  An unlit lamp is nearly opaque, and although it isn't intuitive, so is a lit one.  The lower set of lights will essentially shade the tank from the lamps above them.  But on to the good part....  If you get four full length lamps over the tank, you can keep any of the three listed species of clams if you keep them in the upper half of the tank.  If you can jam six lamps in (shouldn't be too hard), you can keep them anywhere in the tank (assuming all of their other needs are met).  Don't expect outrageous growth rates, but they should remain quite healthy.> Thanks in advance, <always a pleasure!  Adam>
Jon (drawing attached)

Reef lighting How many watts of lighting does a reef tank need per gallon. I have a 75 gallon tank. >> The watts consumed or rated is not much to go on when guesstimating needed/desired illumination for aquariums... for a few obvious and maybe a couple of unknown reasons... Turns out, different means of producing light are more/less efficient in terms of apparent and actual (useful) light yielded per watt (kilowatt hours actually) of electrical consumption... Further, the wattage-required if you will varies in the way of depth, other qualities of system water... And importantly, there is a wide range of what sorts of light/wattage-required depending on the types of light, and what you want it "to do" with a given system... Fish Only systems can be barely lit, SPS Corals, Giant Clams require intense lighting... Now getting down (finally) to some sort of answer... for your 75... probably somewhere in the 160 to 500 watt range... depending on... Just lighting a FO system on the low end... to midway for Fishes with Live Rock and maybe some low-light-using life to the Corals and Clams mentioned on the high end...  Could you "use" even more "wattage"? Yes, to drive photosynthesis, growth, even reproduction of some life forms... are you willing to put in all else that this "driving" requires? Manipulation, testing of water, addition of biominerals... Bob Fenner, who will gladly help you develop an algorithm to explain this answer mathematically

Lighting  Once again I seek knowledge... I read your article on wetwebmedia.com about lighting in the aquarium and did some research on the web. I checked out the Dura-test webpage and couldn't really find a way to order just a few vita-lite bulbs for my tank.  <They're manufacturers... who don't sell to the end-user...> It seems everything that could be ordered was in mass quantity. Also in the area on their page where it talks about use with pets, the bulb it recommended was 20 watts. Is this really enough for a 125 gallon tank, even if I used a couple?  <No, but they do sell larger lamps, larger wattages, power twist (tm) types... The statement you saw probably referred to small mammals, birds...> I know that the spectrum of light is important, but I also thought that wattage was as well. <Yes, as interpreted as intensity... lumens... and per kilowatt energy produced...> I was thinking about using metal halide bulbs, but the cost and the heat factor seem to be keeping me from going that way.  <These are downsides> Plus, you didn't rate them too well in your article.  <MH are appropriate, even the best available, most appropriate technology for very deep (relative to hobby use) systems... with high-intensity light using organisms like SPS corals, tridacnid clams... but the modern Compact Fluorescent light technology can outdo them for function, cost of installation/use, safety.... in almost all cases... most public aquariums are switching to CF's or have done so...> I suppose a disadvantage too would be to have no top on your tank whatsoever when you hang the light from the ceiling. Even so, these bulbs seem to be less expensive than the compact fluorescent bulbs. Sheesh! Talk about forking out a lot of cash!!! I want to have more power than the two standard 30 watt 36" fluorescent bulbs I'm using now, but the choices seem rather confusing. I do plan to get an anemone down the road, and there does seem to be some coral growth on my live rock (it looks like two brown hairy flower buds that haven't opened yet, with tiny circular red mouths) so better lighting seems like the right way to go. Will 20 watt vita-lite bulbs actually work better than compact fluorescents?  <No...> How many would I need? How would I get them? Uhh... my brain is about to explode again, so I guess I should stop. <Don't explode... take a look at the CF retrofit kits FFExpress.com is offering... save up, and install these... this is the best route to go for your 125>  Oh yeah, one more thing. I'm trying to get my 3-stripe damsel out of the tank, but having 90 pounds of live rock in there doesn't help. Do you suggest any special way of coursing the fish into the net? Or should I use 2 nets? Any advice would be helpful, and thanks again. -Matt Lindstrom >> Always use two nets... one to drive the animal, one to lift it from the water... but good luck... maybe training this animal to eat above a "permanently installed net" might work... Bob Fenner

Fluorescent lighting: Best type? Bob, I Have gone through the FAQ's and other responses and have a couple of questions for lighting. I am planning on a having a heavily stocked reef only system. (maybe a few clowns and smaller fish). 1. I understand that I should use 3-5 watts per gallon. But is 3 watts per gallon like Microsoft saying that WindowsNTserver will run on a 486 with 24 megs of Ram? (yes it will but it kills the system operator and it really sucks) I already have 2 units 48 inch with two bulbs each (total 4 bulbs) at 40 watts each. Ready for my new 55gal(std aquarium size here) reef tank that has recently matured. Will this be enough? or is it really a trying to run a fortune 500 company on a 486? I have thought of changing them to the CF but did not fully understand the cost benefit of changing. <Like your comparison, and yes, it is quite apt on a few counts... more, much more to this "story"... The CF's would be better, even at par comparison of watts consumed or produced in lumen equivalence... the useful light produced by these different formats is not the same... sort of like the Intel CPU's with limited cache...> 1. In ranking the least to greatest beneficial usable light output where do CF's fall when comparing them to normal fluorescents, then HO and last VHO. I get different stories from my LFS. <CF's are at the top in terms of production (by watt-production, kilowatt consumed, overall cost per lumen/useful photon... of all these formats> Thanks, Sean Warren Could you respond back to this email so that I may read this while I am traveling. We must decide what we will do in the brightness of day before the night falls and the storms set in <Bob Fenner, who feels like he's in India with the above stmt.>

Still unclear on lighting?  I am still in need of a little help on the ACTINICS lights. I usually think of them as only as for looks only but in your response to another you recommended them are they of any real value in a FO tank or Reef tank? Here is the case were you recommended them. Pasted from your site. <Actinic lighting refers to certain wavelengths ("life-engendering", embodying "actinism", if you will) that are more specifically supplied by "actinic fluorescent lamps"... Are these useful to hobbyists, culturists? Minimally... as enough intensity/lumens/photons of this EMR are provided by most all other lighting modes... For some, mainly deeper-water (collected) organisms that hobbyists utilize, such specialized light production can be worthwhile... but is it "cost effective" relative to "higher Kelvin rated" light sources? Almost always never. Put another way, for the cost of acquisition and operation, neglecting esthetic considerations, actinics are by and large a waste of money for home aquarists. Why are they sold may be your real question? To make money. Why would I (or anyone) reply in a general way to a home hobbyist that they might/should add this sort of lighting? Because I/we have no idea of what they might now or later add to such a system... and yes, some animal groups (tridacnid clams, some Acroporids, Pocilloporids, Faviids...) do demonstrate discernible improvement with accentuating these wavelengths... plus a few other "reasons"... Bob Fenner> > We have just purchased a 110 gallon aquarium, with wet dry filter, protein skimmer and an additional power head. We have also just purchased live rock uncured and cured from FFE. My question is two part (we are novice) 1st I eventually want to add lighting for soft coral, etc. what would you recommend for this size tank. > <If only live soft corals, VHO fluorescents, possibly VHO and Compact Fluorescents (some of actinic, some whites of 5k, 10k temperature)... to Just CF's... If you might go the SPS coral and tridacnid clam route, possibly the addition of two, or even three Metal Halides in addition to some CF actinics...> > #2-The live rock will be coming today, since the tank has been running for over a week, can I cured the live rock in this tank? Please give me your opinion. > <Yes, do cure the live rock in place... see the articles on this and related topics stored at www.wetwebmedia.com> > Its great to know that their are professionals who are there to help > Thank you, Connie > <You're welcome! Bob Fenner>

Lighting?  We're the fish men YEAH! Bob I have read your book and carefully the section about lighting. My questions is this. After finishing I thought that the blue Actinic were of no value except to the human eye. However in the following response you gave you encouraged actinic. I have pasted it here. I am a little confused. I have a 125 (standard measurements.) and a 55. I'm planning the 55 to be a reef tank. Will 4x 48inch reg. 40 watt bulbs and the name brand recommended most in your book be fine for the 55?(the name slips me now but you really spelled it out very clearly). <Probably Dura Corp. (RIP) "Vitalites"... and time marches on my friend... these were the best lighting (to my knowledge) when the section was penned, later published in CMA (in the mid-90's)... compact fluorescents are far better functionally, aesthetically now... and in a few years? Beware of linear thinking and logic in this universe> Also the 125 is fish only with 60lbs of Fiji live rock. would 4 of the 40 watt bulbs be enough. (of course the name and model that you mention in your book. <Not in my opinion... look to the CF technology> Your humble Acolyte, Sean Warren PS. I would hope that this does not appear that I am being anal in taking what you say below here and using it to compare to what you say in the book. It is just that I have tried to consume every thing I can with your name on it, paying attention to every detail that I can. On a funny note I refer to you in virtually every sentence and I start out every part of a conversation with "BOB says ....." and my LFS said," Hey he is not GOD and does not know everything". I disagreed. Lighting <You are seeing things not there my young friend. I am only another struggling human. Of limited capacities, understanding and vigor. Life to you. Bob Fenner>

Fluorescent Lighting Hi Bob, I have a 72 gal bow front marine aquarium. It is a fish only tank with 2 standard fluorescent tubes. 1 - Hagen Power-Glo 48" 40w T10 ( Lumens 2200, Lux 180, Kelvin 18000K) The other is a Hagen Marine-Glo 48" 40w T10 Actinic Blue (Lux 105) <Okay> Is this lighting adequate? If not, what in your opinion is a better choice? <Adequate for? A fish only system? Yes... for one with live rock? No, you need about two-three times the amount of intensity (useful illumination) as stated. For most of the types of photosynthetic life folks keep? No, you need about three to four times the amount... For the higher/est photosynthetic life like many of the SPS corals, tridacnid clams...? No, you need at least four times this amount and five or six more times would be better/optimum... Please read over the "Light", "Lighting" sections on the marine index on our website: www.WetWebMedia.com and all the associated FAQs files here... You should come to understand the underlying science and technology and your options for getting the intensity and quality of light energy you're looking for such a size, shape system and purposes you intend, with what livestock you're considering...> Thanks always for your help. Ed <Study my friend. Bob Fenner>

Lighting for reef tank Bob, I am interested to maintain a 36 x 18 x18" tank with live rocks and under gravel filtering system. I plan to keep a wide range of mushroom corals, shrimps and macroalgae and clay fish also. <Clown?> As for fish I like the flame angel or African clown fish. <One's from Africa?> But I AM concern about lighting and the LFS only offer 2 type only. 1) 3' Coralife High Intensity Purified Super Daylight Lamp ( 10,000 k ) 2) 3' Solar Nature Full Spectrum Color Lamp ( 6,000 k ) from Germany. My question is which is most appropriate for reef tank and how many are needed for my case??? Thank you in advance. David. <Hmm, both would work... In fact I would use both, maybe one of #1 and one or two of #2 myself for the anemones that you may end up trying. Also do look into compact fluorescents for your new system. Much more on your lighting options can be found on the site: www.WetWebMedia.com under the "Marine Index". Be chatting my friend. Bob Fenner>

Marine aquarium lights Hi Bob, I have a tall 27inches high 60 gal octagonal tank with three 15 watts fluorescent lights, one full spectrum, one Actinic and one 50/50. There is no room for more lights so I hope this is enough. Is this the right choice or should I have 2 full spectrum and one Actinic instead? I have a few fishes and I would like to get a few anemones if it is possible. <No to the anemones (if the popular photosynthetic types... you don't have near enough light). And the lighting you have is fine for fishes... if you wanted high-light need livestock, you might consider a single 175 watt pendant type metal halide... but I wouldn't do this in such a shaped system... very hard to control heat-wise> Also there is a glass between the lights and the water I know you suggest removing it but doesn't it protect the lights from corrosion? <Yes. Many folks use water-proof end caps over their lamps in such settings> or maybe it helps keeping the heat from the lights away from water, it's hard enough keeping the water temperature constant I'm worried that if I remove it the temperature changes will be greater when the lights are on then off. thanks so much for your help. Marc <Methinks you're ready for a larger system my friend... Bob Fenner>

Re: marine aquarium lights Thanks Rob, so you would say even with my system it's much better to remove the glass between the lights and water? <Yes, almost always the case> as far as heat from the lights you mean it makes no difference with our without the glass? <Makes some... actually in the vast majority of circumstances, this improves overheating... from evaporation> you seem to think that octagonal shaped system is difficult, why? -Marc <The "foot stamp" or surface area versus volume relationship... relative to more "stock" rectangular shaped systems... harder to aquascape, keep filtered, gaseous distribution hindered... Bob Fenner>

Shop Lights?| Have a question about lighting. I want to add more light to a 100 gallon tank. I'm thinking about using a shop light that you would get at the hardware store. I have a large oak canopy that covers the tank so the lights are not visible. I want the light for fish only and some live rock do you see any problems with going this route. <nothing dreadful, although the fixture is not designed or warranted for applications near water. Although many folks safely use them, they can be a bit of a hazard. Rather than buy three new fixtures in two years because they keep rusting out or shocking you... take a little time to look for a good price on a proper normal output (SO) fixture new, or even search locally for a used one in the paper or the LFS. Did you look online at some of the vendors in the links and beyond?> Thank You, John <regards, Anthony>

Reef Lighting  Aloha, <Greetings.> I have a 75 Gallon tank. I am not wanting to take a shortcut on lighting. I want to keep some SPS and clams. I keep my house cool (about 70 degrees) I will have 4 - 4" fans in my custom enclosed canopy over the tank (hanging pendant- style out of the question unfortunately). My canopy will be about 8 to 12 inches over the tank. I plan to purchase a sheet of polished aluminum and line the entire inside with it. <I'd get it at least coated with something... aluminum and saltwater don't mix well.> On to the lighting... I would like to retrofit 2 - 175watt 10,000K metal halides.  Complementing that, I can either buy an Icecap 430 and run 2 110watt actinics, OR I can purchase a 660 and run 2 110watt actinics PLUS 2 110watt 10,000K bulbs along with the halides. Is this overkill? <Hard to discern... you probably don't 'need' the extra 10K fluorescents.> Again, I would like a T. maxima or T. crocea in the near future. But I don't want to burn the SPS corals. <Make shady areas with the rock work OR drop one of the metal halides and light with the other on one side of the tank only, and then perhaps use the 10K VHOs on the side that doesn't have the MH lighting.> OK, if you're still with me, back to the MH. I have heard about UV rays, so I assume I will have to build some sort of UV lens for my MH. <That is correct.> Is this a special type of material or could I use a piece of acrylic? <I would use glass - acrylic will likely melt being that close to a lamp. Glass is available with a UV-filtering coating.> I could build a " box" over each bulb with it. Not sure if the bulb would melt it though. <It would.> I really don't want a piece of glass or acrylic over my entire water surface. I want evaporation for Kalk top-offs and cooling factor (with the fans blowing across the top of the water). <You might need to rethink this, with fans sucking hot air out of the canopy.> I am trying to come up with a plan to where I do not have to use a chiller, but get sufficient lighting. <I'd skip the canopy and instead light from above with adequate space for more fans. You will soon see that the canopy becomes a trap for heat, and you largest problem will be getting the heat out of the collector.> I have so many ideas in my head so if you could blindfold me, spin me around 15 times and point me in the right direction, that would be super cool groovyrific!! <Again... if SPS is part of your goals, then skip the second MH. Light that side with only fluorescents. You will still have issues with heat... you may need more fans or you may even need a chiller. Time will tell.>  Mahalo, Jason <Cheers, J -- >

Lights for a FOWLR Hi Guys, First off, your website is awesome!!!  Most informative, especially for the novice marine aquarist, but sometimes since I'm a novice, it makes my decision making difficult, so I'm going to ask the pros.  Anyway, I've got a 46 gallon bow-front, that is 24" deep and 36" wide.  I am currently using the factory bulb issued with the aquarium hood.  I'm interested in getting a couple of pieces of live rock to provide some natural grazing ground for my Kole Tang and Yellow Tang.  I also have a couple of clowns and a Brazilian Gramma, and will eventually be adding some cleaner shrimp and hermit crabs, etc.  What are the lighting needs to just support live rock?  << Well basically none in terms of biological filtration.  But the more light (and I think the more blue light) you have the more you can grow.  So if it is for herbivory then I'd say as much light as you can get. >> I would like to continue to use my factory hood (which only supports one bulb), but which bulb should I be using?  I was looking at a Zoo Med Reef 50/50 Bulb, but it's only 25 watts.  Your advice is much appreciated. << Well that is a fine bulb, but I'd consider taking apart the light and gutting it out to hold either a VHO light or multiple pc lights.  If not, you are really limited on what the live rock will grow.  However, even without light, live rock is excellent to have. >> Once again, love your website!!! The Novice <<  Blundell  >>

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