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FAQs about Light and Lighting for Marine Systems, Lamp/Bulb Selection 1

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Related FAQs: Marine System Lighting, Marine System Lighting 2, FAQs 3, FAQs 4, FAQs 5, FAQs 6, FAQs 7, FAQs 8, FAQs 9, FAQs 10, FAQs 11, FAQs 12, FAQs 13, FAQs 14, FAQs 15, FAQs 16, FAQs 17, FAQs 18, & FAQs on Marine Lighting: Fixture Selection 1,  Fixture Selection 2, Fixture Selection 3,  (incandescent, fluorescent, MH/HQI, LED, natural...), Lamp/Bulb Selection 2, (See Fluorescent, LED, MH... below), Installing, Waste Heat Production/Elimination, UV Shielding, Measure, Troubles/Repairs, By Manufacturer Make/Model: & Actinic Lighting, Metal Halide Lighting, Fluorescent Lighting, Compact Fluorescent Lighting Small System Lighting, Lighting Marine Invertebrates LR LightingTridacnid Lighting

Initial cost is only part of the equation... what are you getting... for what you are seeking in terms of looks, functionality... per operational and replacement costs? Oh, and there are indeed quality differences twixt actual manufacturers and re-labelers

Kelvin Ratings in the Reef Tank  12/26/05 Mr. Fenner, <Hi Jon, this is Adam, I'll be your substitution for Mr. Fenner tonight.> Thank you and your crew for operating one of the most valuable websites out there for aquariums. <And thank you for the kind words.> It is always the first place I go for answers.  Anyway,  it's the holiday season again, and once again I enter the world of "close but not exactly" in terms of gifts for the aquarium. <Lets see if I can help you out.> I have a 29G reef setup with 2X65watt power compacts.  One of the replacement bulbs I got for Christmas is a 12000K vs. a 10000K I have been using.  My understanding is that the 12000K represents "deeper" light than the 10000K, but I don't know by how much, or, more importantly, what the effect would be on my corals. <Generally speaking photosynthetic animals prefer Kelvin ratings in the 6500K to 10000K range, 12,000K probably has a slight blue tint to it comparison to 10,000K but it should be acceptable.> Is it ok to use, or should I go back for the 10000K.   <Shouldn't be to much of a noticeable difference.> For corals and inverts, I have a Bubbletip anemone (I know, I know...no place if a reef tank, but it's really well behaved:)) <Okay you can slide this time.> , frogspawn, Zoanthids, assorted mushrooms, Ricordea, star polyps, and pom-pom xenia. Again, appreciate the wonderful service you provide with the website! <You are quite welcome, Merry Christmas and Happy Holidays.> Jon Gage <Adam J.>

Lighting/Color Temperature   2/7/06 Good Morning, <Good morning to you, James.  What a nice name.  You must be handsome also.> I have finally decided to jump and recently upgraded from power compacts (130w 10,000K and 130w actinics) to metal halides. The current bulbs on the two metal halides are 10,000K 150w double ended with supplemental lighting of two 96w PC actinics. Would it be possible to use 20,000K 150w metal halides and not bother using the power compacts? <Sure> Shouldn't the 20,000K provide enough of the blue end spectrum? <Yes> From what I understand, 10,000K would provide better growth for the corals (my main concerns are the maxima clam, yellow leather and pipe organ). <I recall reading somewhere that clams prefer the lower color temperatures (6500-10000, but also read that Barry Neigut of Clams Direct uses both 10 and 20K lamps.  Corals do seem to do better in the 10K range, personal experience.> I'm not too concerned with growth as my tank is only a 55g tank, I just want to be sure this would keep the corals healthy at only two 20,000K 150w metal halides or does growth and health go hand in hand?<Definitely> I also would rather use the 20,000K for aesthetics, hoping for a two in one shot with the 20,000K! I may just use the PC's for a dawn to dusk effect. <Bottom line James, if I had your set up I'd go with 14K lamps and you will get the best of both worlds.> Thank you for any assistance you can provide! <James (Salty Dog)> James Color Temperature/Photo-Period - 09/03/06 Dear Crew, <<Hello...EricR here>> The fluorescent ballast on my ARAD 48" fixture stopped working yesterday so my reef tank is now running solely with the HQI lights. <<Shouldn't be a problem>> Until now, my 75-gallon tank had the daily benefit of 6 hours of 2 x 150-watt 10K HQI lighting and 12 hours of 36-watt NO actinic fluorescent lighting. (I never installed the other 36-watt tube.) <<Mmm, you should increase the photo-period for the MH lighting  to about 12 hours.  Daylight in the tropics will average around 13 hours, with a very small seasonal variation.  Though some species are highly adaptable, running such an unnatural light schedule will likely result in long-term deleterious effects.  Please read here and among the indices in blue: http://www.wetwebmedia.com/marlgtganthony.htm>> Without supplemental actinics, what should I increase the photoperiod of the HQI lighting to? <<12 hours...whether supplementing with actinics or not>> Without supplemental actinics, which color temperature should I select for HQI bulbs? <<The 10000K are fine (plenty of "blue" for the corals needs), but if "you" want a bit more blue then go with a 12000K-14000K bulb>> I am considering replacing my current fixture with a SunPod 14K HQI fixture with LED's for twilight viewing.  Again, there is no actinic supplemental lighting. <<And it is not necessary...in most all cases, the supplementation of actinic lighting is for the aquarist's/onlooker's benefit...even 6500K metal halide lamps contain enough light in the "blue" spectrum for most any coral's needs>> My reasoning is that in nature, there is very little actinic solar radiation at twilight hours when the atmosphere is permitting primarily red light.  Am I correct? <<Maybe so...but "twilight" only lasts for moments...not the 6-hours per day you were running previously>> Thanks very much! <<Happy to assist>> Best regards, Paul <<Cheers, EricR>>

Lighting Spectrum Selection - 04/27/05 Hey, I'm about to buy bulbs for two separate set ups and I was had a few questions about which spectrum bulbs I should choose. The first is a saltwater tank that has a harlequin tusk as my center piece. I have live rock but no other inverts. My current pc bulbs are 10k and actinic but I have the ability to add a 6700k bulb along with the 10k and actinic when I replace them all. I was wondering would this accentuate the orange of my harlequin because it is stronger in that part of the spectrum? My main concern is the aesthetics of my fish in other words.  <The spectrum you mention will highlight the fish's color more dramatically.> My other question is about a freshwater tank I have set up for an adult largemouth bass. It's a 220g with four 36w standard florescent bulbs. I do a lot of fisheries work and understand that adult bass prefer deeper waters (10-20ft) away from higher intensity sunlight. so I was thinking that a higher Kelvin bulb would more closely resemble its natural habitat. Do you think that 18000-20000K bulbs would be more natural or better simulate the spectrum that these fish prefer?  <It's hard to say. On the reefs the water is much clearer than in a lake so the lighting in 15 feet of reef water is going to be brighter than in 15 feet of lake water. I'd probably keep what you have. James (Salty Dog)>

Spectrum Selection (Not a big deal...this time!) - 04/27/05 Hey, < Hey Brandon...and for future reference...please use proper punctuation when writing in. > I'm about to buy bulbs for two separate set ups and I was had a few questions about which spectrum bulbs I should choose. The first is a saltwater tank that has a harlequin tusk as my centerpiece. < Lovely fish. > I have live rock but no other inverts. My current pc bulbs are 10k and actinic but I have the ability to add a 6700k bulb along with the 10k and actinic when I replace them all. I was wondering would this accentuate the orange of my harlequin because it is stronger in that part of the spectrum? My main concern is the aesthetics of my fish in other words. < Warmer colors will likely provide the look you're after. While pleasing and even necessary for some applications, the higher Kelvin bulbs tend to skew (or wash out) colors in my opinion. I would '86' the actinic bulbs altogether and go with more bulbs in the 6700K range for this setup. > My other question is about a freshwater tank I have set up for an adult largemouth bass. < Another "neato" and interesting fish. > It's a 220g with four 36w standard florescent bulbs. I do a lot of fisheries work and understand that adult bass prefer deeper waters (10-20ft) away from higher intensity sunlight. So I was thinking that a higher Kelvin bulb would more closely resemble its natural habitat. Do you think that 18000-20000K bulbs would be more natural or better simulate the spectrum that these fish prefer? < Hmm, with proper aquascaping/structure, the fish will find a spot with a light intensity that's suitable. My first inclination would be to keep the standard wattage bulbs but reduce the number to three to dim the lighting as seen in many public displays of this type...but your idea has merit. If you're willing to go to the trouble/expense, four 55w/65w PC bulbs in the 14K - 20K range could well be a more natural look/condition for the fish. > Thanks again, Brandon. < Welcome, Eric R. > 

More SW light on the cheap I currently have a 29 gallon reef tank.  My question pertains to lighting.  Right now I have a 65 watt true actinic blue and a 65 watt 10000k day lamp.  What I want to know is... is there a supplemental light I can add. I don't have the disposable income now to purchase a $300-400 light, but is there a smaller bulb that can be added to the existing setup. My goal is to sneak in at least another 65 watts. <I'd just trade out the actinic for another "white" lamp. Please see here: http://www.wetwebmedia.com/marine/setup/lighting/actinicfaqs.htm Bob Fenner>

Lighting color choice 4/9/04  Hellooo all, Thanks ahead of time for the help. I have a few lighting questions. Right now I'm using 4 3ft VHO bulbs over my tank (70g tall 36x18x24). There are 2 actinics along with 1 50/50 and one 10k spectrum bulb. One of my questions is should I buy more 10k or 50/50 bulbs if I want more usable light? I've read on this site and many others that the actinics don't really have much use to corals at all. Regular "white" spectrum lights have enough blue to provide for all the inhabitants. So, I was thinking to change my 2 actinics for a 50/50 and 10k. Then I'd have 4 "white" lights which I would think would be better for my tank, however, is four 3 footers enough for such a tall tank (24")? I was thinking of upgrading my lights to some MHs but wanted to consult you guys first. thanks again!! Chris aka fishtank.  <The color of the lamps that you choose is mostly an aesthetic choice. Whiter lamps may produce slightly more usable light, but not by a large margin. Four lamps over a 24" tank is plenty for a wide variety of animals, although some very high light animals (shallow water Acroporas and clams, mostly) may not hold their color or grow very fast. If you wish to keep some of these very high light animals, you may want to consider MH, otherwise, choose your florescent lamps based on the appearance that you find pleasing. As a side note.... Unlike with fluorescents, the general rule that bluer lamps produce less output is very true with MH. Best Regards. Adam>

Question on Lighting Spectrum 5/1/04 I just had the opportunity to purchase a rose bulb anemone, E. quadricolor, at an amazingly low price. I decided to go ahead and not pass up this offer. For the occasion, I am going to put it in a 20G tank that is already started until my big tank (125G) is up and running in about 2 months. <good... much better than putting it in a tank with other stinging animals/corals... they fare best in biotope and species specific displays by far. Less room to roam and get into trouble too! <G>> To facilitate this anemone, I just purchased a major light upgrade to PCs, and there will be about 8.5 watts per gallon. My question is this, the fixture has two separate bulbs, both independently controlled. It came with one 10,000K bulb and one actinic bulb. Do I really need an actinic bulb since the depth is only 12"? Or would I be better off going with two 10,000K bulbs? <2 10k K lamps would be more useful by far> Finally, is it correct to assume that 8.5 watts of light per gallon in that shallow of a tank is acceptable? <for this anemone, yes... if acclimated slowly (using screen method, staggered light schedule, etc) to adjust from previous light scheme if lower (merchants tank, wholesaler's tank, etc.> It will be supplementally fed with seafood <very good... a variety of very finely minced meats of marine origin including Mysid shrimp and pacific plankton (tiny krill) would be very nice> and Mark Weiss ComboVital as well. <errrr.... interesting.> Thanks! <best regards, Anthony>

Lighting 2/2/04 I have been reading a lot about lighting, and have been hearing a ton of different opinions.   <not much controversy needed if/when you tale the time to pick a compatible group of corals/inverts and then address their lighting needs. Shallow water SPS corals = bright, warm daylight (6k K to 7k K)... deep water Corallimorphs and LPS (moderate wattage cooler lamps (10k K range)... Metal Halides over 30" + deep tanks... fluorescents are fine over less deep tanks, etc)> I have a 55 gallon tank with a 2x65 watt Coralife Aqualight.  I am trying to do low-light soft corals for now and will eventually upgrade to a 4x65 watt light or a metal halide.  For corals I have some kind of colonial anemone (I think it is Palythoa - the store had it marked as Goniopora but it is definitely not), a green star polyp, and a tiny stalk of non-pulsing Xenia high in the tank.  Is my lighting adequate for what I have now? <It seems weak even for low-med light soft corals unless you can heap all within 10" of the surface> What other low light soft corals would you recommend for the setup I have?  I am trying to find something very colorful.  Thanks, Ken <low light soft corals tend to be brown my friend... because, in part, they do not need the colorful proteins to reflect excessive (not here) UV light. Your best bet for color in this case will be Corallimorphs and Zoanthids in my opinion. For a lighting upgrade, you would not be disappointed to add a single 150 watt double ended HQI lamp to the present outfit. Excellent all-around light. Anthony>

Lighting question 10k K vs. 20k K 1/30/04 Thanks for the quick reply. One last Q....I have 20,000K hi intensity white (fluorescents). What's the major difference between 10,000K and 20,000K...? <the cooler temp of the 20k K bulb indicates that it peaks high/excessively in the cooler (blue/violet, etc) end of the spectrum. This makes some corals look very nice, but is far more "blue-white" than needed by any coral. This color light is produced at the expense of warmer daylight which could yield better growth for you. I recommend 6500-10k K if good growth is a primary goal. Anthony>

Lighting Question III 2/2/04 So 2(Two) 20W 10,000K hi intensity and 1 20W 20,000K Actinic is the best way to go for growth....Thanks Jess <not exactly... quoting from our last e-mail: "I recommend 6500-10k K if good growth is a primary goal." And to be even more specific, lamps with colors over 10k K are frankly excessive it he blue spectrum. Use them only if you want/need them for aesthetics (a good reason... but not for maximum growth). Anthony>

Lighting...question IV 2/3/04 OK...one last time....sorry....What if I changed them to be all 50/50's....I'm looking for growth vs. aesthetics.... <your inexperience is shining through, and that's not a bad thing. But you simply need to do more reading/research before rapid firing questions or making impulse purchases. 50/50 is not a lamp color (as indicated by a CRI rating or a color temperature in Kelvin)... it is a marketing/trade name. For the 3rd time, my friend... seek bulbs in the 6500 0 10,000 Kelvin range of color for optimal growth of most popular corals. Speaking to the 50/50s you have seen... you need to discover if that particular lamp falls within that color range if you'll take my advice. Anthony>

Lighting (suggestions) discrepancies Dear Bob, Why does Anthony Calfo say to choose a light with a minimum 6500 K to 10,000 while you indicate that between 5000 to 6200 which is equivalent of our sun. Am I reading incorrectly? Anthony also indicates that below 6500 will allow growth of nuisance algae. I was set to purchase Vita-lite plus but now I am confused. Any clarifications would be greatly appreciated. Chris <Mmm, will have to ask Anthony here as well... my opinion is that most anything above 5,000 Kelvin is fine for most marine aquarium use... higher incandescent temperatures are fine... and though the light-extinction coefficient works against their penetration in water as well, do "look nicer" to many folks... do get more useful (PAR) light/lumens/photons down to photosynthates... One way I might put this apparent difference (if Anthony weren't about to respond), would be that he thinks starting with a higher temperature light source works better. Bob Fenner>

Re: Lighting (suggestions) discrepancies Agreed. The warmer/more natural Kelvin lamps are much better for growing most coral. Aquarists keeping shallow water species report better results with using lamps in that 6k K range. But do keep in perspective, Chris, that you need to choose your corals before you select your lamps (and before you hold anyone accountable for a necessarily generalized statement;)) If you end up keeping a mixed garden reef tank like most folks with (unnatural) mixes of corals/Corallimorphs/Zoanthids from rather deep and fairly shallow water alike, then you will need a more standardized lighting to suit all. And if the Corallimorphs and Euphylliids (octopus, torch, hammer, fox corals), e.g., do not wince under heavy daylight, they at least will look simply awful. They are some of the popular corals that favor a cooler colored lamp.  Add to this mix the too common reality of weak water changes and modest skimming in many aquarists tanks and you get a recipe for accelerated brown algae growth under very warm lights.  So either lighting scheme can work well with some finesse.  My hope is that you plan for long term success and make your list of corals in advance to replicate a more natural biotope (shallow water sps, deep water soft corals, gorgs of the Carib, etc) and do not make your hobby and more difficult by keeping unnatural tankmates.  Its much easier to tailor hardware (lights, water flow, etc) when you do this... and a much more attractive presentation IMO. Best regards, Anthony

Lighting discrepancies II 1/30/04 Anthony, Thank you for your quick response. <very welcome my friend>> I  have been out of the marine aquarium or about 12 years and have now a custom in wall tank of 280 gal. empty. <ah, welcome back my!> Lots have changed, or I guess I should say, lots of advancements since. <exactly... even in just the last 5 years. The commonplace breeding and rearing of seahorses... tangs being spawned... dwarf angles (Flame, Interruptus) being produced commercial/tank-raised, etc> Please do not think I meant any harm. I am overjoyed with the site. What an education you guys give.  <no offense taken at all, my friend... and my concise emphasis was intended to help you and in light of the number of questions we get on this topic. Its easy for one to get led astray. Moreover, lighting technologies evolve faster than most any other in our biz... thus, something written 6 months ago can easily be outdated. 'Tis the reason for evaluating your tank inhabitants needs before pondering what lights to buy. Else its like putting the cart before the horse> I am simply at a loss and wanted clarifications for my own info. I failed to mention that the tank will be a fish only (for now).  <ahh... all good. At this point, make your decision largely on aesthetics (liking more yellow/warm light or blue/cool whites). For like rock health, future  corals and a slight edge on nuisance algae... I still suggest you opt for a slightly bluer color (closer to 10k K rather than 6k K)> It is epoxied plywood three sides with the face side glass with synthetic coral also epoxied to the rear wall of the tank that in my opinion looks quit realistic. <sounds very neat> I hope to be able to keep it this way without having lots of algae cover them. They are colored very realistically. They cost a lot and have come from various sources. I even was even going to use a trickle wet dry filter that I purchased and now after reading about nitrates that result (also adding to algae) I have decided to use a large skimmer (aqua c I think) and in the sump add live rock or live sand.  <yes... agreed... live rock, skimmer, love sand and skip the trickle filter unless you plan to keep rather large fishes> Could I impose on you again? I read that Knop Aquarientechnik has a good air skimmer that supposedly accomplishes better results (that is, removes more bad stuff and less good stuff) than downdrafts and venturi. Is this true? <different styles of skimmer (air driven, various venturis... aspirated, downdraft, spray infection, etc) each do pull different components... each with advantages. My personal experience with many years of air driven 6' German-style skimmers in my greenhouse and personal displays sides with air driven models.  And Knop is an excellent brand> Could you help me with what size and type of skimmer is best? Money is not an option. <simply heed the manufactures advice and size up at least one model for room> Should I also put live sand on the tank bottom and if so how much? <in the display... 1/2 inch or less or over 4" for denitrification. You can also get denitrification from a deep bucket of sand tapped inline below with the sump/plumbing instead of a deep sand bed in the display> I really do not have a lot of room for much live rock in the tank with all the artificial corals. <this is clearly a big disadvantage. Perhaps keep a vat/vessel of live rock inline below with the sump/filtration> Should I put live sand or live rock in the sump.  <either or both. Do get out to see some local aquarists displays for perspective. Find a local or regional aquarium club (keyword search on the net, our WWM links, message boars like reefcentral.com) with forums. The experience and perspective will be invaluable> I am hoping to achieve good water quality with the protein skimmer and live rock/sand. I even am thinking of two skimmers. One for the skim layer of water and one to be placed in a sump. I simply want no ugly algae to form. <the algae is natural and inevitable. Can be controlled with aggressive skimming (two skimmers cleaned alternately are better than one... do consider)> I will purchase a RO/DI. Any recommendations here?  Kent has a model Max60HiS 4 stage that sounds good to me. <I am not a big fan of Kent products for many years. Do check the message boards here for consumer perspective on what's hot and what's not currently. My personal choice is a Kati/Ani 2-column deionizer (no waste water... a beauty). Drs Foster and Smiths are one of the bigger distributors of this model.> Thank you, Chris Drialo. <best of luck! Anthony>

Re: Lighting Question Hi WWM crew, sorry to bother you again but I once again need your assistance.  I only have one question today.  Will metal halide bulbs from home depot suffice in my 180 gallon tank?  Is there any danger to purchasing these lights instead of purchasing them from my LFS?  Thank you. <This depends on the color rendition of these bulbs. Unlikely. The bulbs from your LFS or on-line stores are designed to produce the proper light spectrum and intensity for your corals instead of lighting the garage. These could work with additional lighting to supply the needed spectrum in addition to the output of the standard bulbs. IOW, you won't save a penny purchasing these bulbs instead of the bulbs designed specifically for corals. There is MUCH difference in output/color/intensity/growth rate, etc. between bulbs, do take time to shop around and SEE the difference. Best of luck!  Craig>

Lighting question: the best bulbs are...??  (02/16/03) Sorry to keep hounding you guys, but I'm going to anyway.  :) <That's what we're here for, just gluttons for punishment... oops, I mean, fun! Seriously, if we didn't like doing this, we wouldn't.> Reading a couple of articles on the WetWebMedia I have drawn the conclusion that you seem to prefer NO fluorescent over any other light source. <For the typical fish-only or fish-only with live rock tank, and most freshwater tanks, yes... but definitely not in all cases.> I need to ask a few qualifying questions.  I have heard that metal halide lights are better at penetrating the water than fluorescent... is this true?   <Yep.> I have a 24" deep tank with 2-3" of substrate... will fluorescent be good enough?   <As always, it depends on what you want to have in the tank.> I'm sure more information is required to answer that question, so here goes: I would like to house mostly SPS and clams and because of my tank's dimensions I would have to use VHO rather than NO fluorescent... 440 watts for a 90 gallon tank.  By the (albeit, rudimentary) rules of thumb, almost 5 watts/gallon should be sufficient for these creatures.   <Hunh. Some SPS's need more light than others. The same is true of clams. The most brightly-colored clams might want more light than that.> This number isn't far off the 500 watts of metal halide my LFS wants to get me into for about $1000 US.  Are watts watts, and lumens lumens, or is there a difference in the quality of the light from each source.   <I'm learning to really dislike wattage as a measurement of lighting. It's how much energy the bulb uses, not how bright the bulb is. That's why you see those fancy fluorescent bulbs labeled with things like "11 watts -- as bright as a 60 watt bulb!" (or whatever the exact numbers are). There is a noticeable difference in the way VHOs look vs. the way metal halides look, not to mention the differences in the way various colors of bulb look.> I really like the affordability of the Ice Cap electronic VHO ballast system (both up front, and in terms of energy costs). <You also need to consider bulb replacement costs. You're looking at several VHO bulbs, replaced at six-to-nine month intervals vs. two metal halide bulbs, replaced at twelve-to-fifteen month intervals.> Related to that:  the articles go on to say that the effective life (not actual life) of all the bulbs tends to be the same, and all should be replaced approximately every year.   <Hmmm. Probably more true when it was written than now, as bulb manufacturers are making improvements and changes... > My LFS sells Coralife VHO tubes at very reasonable prices, and assuming the bulbs all last about the same amount of time, the VHO seems to be the best cost / watt X hour factor of any lighting system (including MH and power compact).  Your thoughts please. <Do some more comparison shopping, particularly at the on-line sources for lighting.> Finally: two articles actually list the effective life of fluorescents at different values;  one says 1 year, one says 2.  What's the final word on this (my instinct says 1 year)?   <I hesitate to give a "final" wording on this... But my gut tells me that effective life over the display tank might be one year, with possibly another year over the refugium....> How close to the surface of the tank could I situate the 4VHO tube configuration I'm thinking about to maximize the light that penetrates the water. <I would recommend metal halides instead, perhaps with VHO or compact fluorescent actinics. The actinics could be situated a couple of inches above the water, as long as you have them behind something to keep the salt spray away from them and adequate cooling in the canopy.> Again, thanks for your input, and know that I made every effort to actually try to figure something out for myself before I came crying to you guys.  :) Jeremy <You're welcome, and thanks for doing the research first. --Ananda>

Throwing Some Light On Things! Sorry to pester you busy folks again. <Never a bother- that's why we're here! Scott F. with you today!> I recently acquired an Ice Cap 430 ballast for the 90 gal. FOWLR tank I'm trying to get set-up.  What bulb or bulb combination would be best for the coralline & macro algae in the tank, as well as make the fish look their best?  I've read about the 10,000K & 12,000K 50/50 bulbs.  Should I use them by themselves, or with actinic? <I like the 10000k/actinic combo, myself> Also, on the IceCap applications page, it indicates that this ballast will run 3  4' 110 w. bulbs, but Champion & other sites say only 2.  Which is right? <Hmm- I always thought that the 430 powers up to four 2 ft bulbs (for a total of 320 watts). Both of your information sources are obviously knowledgeable (Ice cap makes 'em, Champion sells and uses 'em).  Not to take anything away from the good people at Champion (a great source, IMO), I'd talk to the people at Ice Cap in their R & D department. These guys could tell you exactly what this ballast was manufactured to do, and how best to maximize it's efficiency. Should I decide later to turn this into a reef tank, with corals & anemones, how many VHO bulbs will I need to properly light the tank? <Totally dependent upon the types of corals that you are keeping, how far the light source is from the surface, etc. I'd err on the side of conservatism and get a larger Ice Cap ballast> I'm thinking the addition of a IC 660 4 bulb  ballast will work. <Yep- just my thinking! LOL> That will give me 6 or 7 110 w bulbs.  I was sorry to hear that Duro Test went "belly up".  They made a good product.  Used their lights for years in my freshwater planted tanks.    <I loved those Vita Lites, especially the "power twists". Bummer> Thanks again for your time. Neil <Thanks for stopping by, Neil. I think both of those ballasts are great products, so you'll be fine. Good luck! Regards, Scott F.>

A Horse Of A Different Color? Hello! <Hi there! Scott F. here> I've heard about positive reaction on seahorses' coloration to 50/50 pink white bulbs. Do You know something about it. <Not specifically regarding the light bulbs- but these are nice bulbs> In my country - Poland only available seahorses are  H. kuda and I'd really love to have red ones. What can I do? Do red environment (red algae), red background? <Yes, sort of! They will often take on the color of their environment- I'd try to use some red colored artificial corals, plants, etc. to "assist" them> Or add some red light (Fluora by Osram) to 10000K and tl03? to make algae grow ad seahorses turn red? Maybe 20000K light? <I'd stick to the 50/50s or 20000ks. The red light will not look too nice, IMO!> Best regards. Darek <Thanks for stopping by, Darek! Good luck!>

Bulb Color Temp...still misunderstood Hi Crew!! <Cheers, Bill> Thanks to Mr. Fenner for a great book, I am excited about the upcoming release from the 'whole club'!!!    <agreed... and thanks kindly :)  > OK, to my question,  I have a new 100W MH ballast, I was thinking of using it on my 30g FOWLR and converting to reef type plan.  The only decent bulb I can find for a 100W MH is 5500K,  can I supplement a 5500K bulb with blue, probably PCs, and not cause a major issue with problem species growth?    <a fine idea. No worries... 5500K light can grow reef invertebrates well. It is a warm daylight color and quite useful for many shallow water corals and algae/plants. Just be mindful of good nutrient control (fine-tuned skimming, water changes, careful feeding, etc). Warm light is prone to stimulating some nuisance algae growth. All is easily tempered though with nutrient cycling> I know there is no such thing as a 'rule' but how about a 'guideline' or 'starting point' for lighting wattage and color?   <anywhere between 5500K and 10K is fine by me for coral growth. And it is better for desirable plants and algae. Over 10K is too blue and simply an aesthetic preference by aquarists> As always, thank you for the time, effort, care, conscience and energy you put into the hobby.   <best regards, Anthony>

Lighting and corals with tiny little sunglasses Hi again, crew... <cheers> I read the Calfo article on lighting...helpful, but doesn't answer my main question: what's the best way to shift the lighting in the tank a little more blue when the halides are on?  <bluer halogen lamps (20K) or add fluorescent blue (VHO actinics)> Recap: 75 gallon tall (24" deep), 2 250W 10K MH, 4 55W PC actinic. Sounds like a lot of light now,  <sounds like?! It is a lot of light, my friend. Too much for almost everything you will want to keep unless you are keeping only shallow water SPS corals and clams. Even then it is a stretch> but at the time I installed, it was recommended by several sources.  <OK... but do consider that these sources might be wrong or inexperienced (tanks set up less just a few years). I assure you that many corals will seem to fare well for as much as a year before suffering from photoinhibition. Pale colors, mysterious deaths (zooxanthellae shut-down and corals starves), etc. I still haven't heard your complete livestock selection (fishes and corals) but again... this much light lets you safely keep less than 20% of what's on the market>> Very white when the MHs are on, even with the actinic PCs. Should I lower the 2 250Ws to 2 175Ws?  <that would be awesome... and if you really like blue color, do get 20K Radiums... the best of the blue halides> Change the spectrum on the bulbs from 10K to 14K, or even 20K?  <indeed if it suits you. 20K Radiums give a wonderful blue color in my opinion, grow most corals reasonably well and keep most (not all) iridescent pigments from shifting (the sexy colored corals)> And if I change the bulbs, any recommendations on how to break them in?  <the bulbs or the corals?> When I installed the MHs originally, I burned in the bulbs for 100 hours, but I don't have any "spare" ballasts to do that...how critical is the 100 hour break-in?  <not that critical here stepping down from the 250s> And if I lower from 250W to 175W bulbs, is there a way to help the corals and clams keep from suffering in the transition to lower light <regular feedings> levels, or will they even notice?  <they will notice but adapt> A lot of questions, but I'm unsure how to proceed at this point. <no worries at all... I hope we are helping you along!> Again, thanks for your time... Arthur <best regards, Anthony>

Inexpensive lighting being a poor reef keeper who can not afford metal halide at this point, would I be better off with 2 -50/50 and 2- 20,000K Coralife bulbs or 4-20,000 or 4 50/50? I do want to keep several different types of corals and know that many need very high-intensity lighting. <with any such fluorescents... be sure that all corals are kept within the top 10-12" of the water surface and most importantly (!) that the lamps are mounted no further than 3" off the surface of the water. With that said... for optimal coral health, use heavy daylight colored lamps emphasizing 6500-10K colors. 20K lighting is too blue for coral health. 4- 50/50 bulbs might be best. Remember to replace bulbs every 6-10 months for best success. See a lighting synopsis here: http://www.wetwebmedia.com/marlgtganthony.htm > thanks Robert <best regards, Anthony>

REPLACEMENT LAMPS I currently own a 100 gallon aquarium with a few soft corals. The lamps are now 1 year old. <Old for any fluorescent lamp. My rule of thumb is replace NO lamps every 9-12 months, VHO's every 6-9 months, PC every year, and MH's every 12-18 months.> Currently, I'm running 1 50/50, 1 actinic, and 1 AquaSun. To cut down on hair algae and to provide better lighting, I am going to replace the AquaSun and the 50/50 with 2 Aquasuns 10,000 K. Currently, the AquaSun is only 6500 K. Is this a good idea? <It may help somewhat with your hair algae problem, but nutrient control is more important. Whatever your lighting is, if you have too many nutrients, hair algae is going to thrive.> Thanks, Dave d. <Good luck! -Steven Pro>

Lighting Question I recently swapped out my 10K 175w bulb over my 30g tank for the 6500k that came with it, and the leather corals I had in their went nuts. rampant polyp extension and I've seen a lot of growth over the last few weeks. So, I'm curious as I had been lead to believe that you'd get better results with 10K being more like the light conditions found in a reef. <Somewhat analogous from going from Grape Nuts to Count Chocula cereal... oh, and yes.> on a whole 'nother topic... one of the things I've observed about lighting is that there's a fair amount of effort to filter out UV from artificial light. <This is beyond you! How to start here... life filters out these wavelengths... plays "a/the dangerous game" of utilization and screening to prevent genetic and developmental changes... that by and large are not advantageous... and so manufacturers of lumination have done about the same> at the same time, corals assume their colors to protect themselves from said UV that occurs in nature. <A principle advantage. There are others> I've seen several LFS's that had black light fluorescent bulbs in stock, but I didn't have a chance to talk to them about it. I was wondering, would a small UV light (I've seen 13w CF socket bulbs for sale on the internet) running for a short duration (say, the equivalent of "reef noon" over the tank, i.e. the midpoint of the light cycle) for 2 hours (for example, on my tank, the VHO actinics come on at 10am, off at 10pm, MH on at 1pm, off at 9pm, put black light on from say 4:30 - 6:00pm) cause the corals to keep their colors and increase photosynthesis? just an idea. PF <A good one, and yes. Such stimulation has been shown to "work"... I hasten to add, in the grand scheme of enhanced skeletogenesis in Scleractinians, there are other factors of much greater import... e.g. steady alkaline reserve, proportion of alkaline earth cation concentration... Bob Fenner, who will stop bugging you as soon as Barb is off WWM> [Cute, Bob! and "Hi, Pinky!" Barb--] btw, you'da been proud of me. at The Reef Tank/Pacific Northwest Marine Aquarium Society yours truly kicked butt at Reef Jeopardy, in no small part to all the reading I've done of your respective works (BoCPV1 and CMA), and all I've read on the board. If I could'a just remembered to always answer in the form of a question...

Red night viewing lights Hello: <cheers!> I have been reading a lot from your site daily, and love all the available information and resources. I am putting together a 180 gallon reef tank. I would like to have two (? Enough) 4 foot red fluorescent lights for night viewing. My difficulty is trying to find them for sale on the internet. <actually...red plastic sleeves for these bulbs are made for this purpose. Else you could just use incandescent red party bulbs> Would you have any recommendations for where I may purchase these, or viable alternatives? I wasn't really excited about using just incandescent red bulbs due to the potential exposure to moisture, and difficulty getting enough across the tank for viewing. Thanks for the feedback. Dr. Mac <agreed, my friend... I cannot remember the name of the sleeve mfg I saw last but I understand they are common. Some photo hobby shops perhaps have insight on such plastics for fluorescents (dark room lighting). Best regards, Anthony Calfo>

Re: 90 gal reef Thanks for the follow up Steven, is there a metal halide fixture out there for me other than the space light that is light and could be hung above the tank? <I am glad you wrote back. I just read an interesting article last night about double ended lamps vs. single ended lamps and I must admit now that I was wrong before. The entire article is based on dispelling myths about double ended lamps, primarily being that they are more powerful than their single ended counterparts. Basically, double ended lamps do not have a built in UV shield and are generally tested with a reflector while single ended lamps are tested without. This gives the data a skewed picture. The article is here http://www.advancedaquarist.com/issues/aug2002/review.htm> I just haven't found any fixtures that can be supported above the tank. I don't think it would be a good idea to place a metal halide unit right on top of the glass. <Correct> Any suggestions? Ideas? Thanks! <This unit will be fine. Keep your LPS near the bottom, though. -Steven Pro>

Lighting and More Lighting So should I go with the Ushio or AB?  <both bulbs are excellent... and the question would be impossible to answer even if not so. One cannot select lighting so specifically without knowing what inverts you will keep and their respective needs (peaking on blue end of spectrum or closer to daylight/red, etc)> Is a AB hood of good quality or is there something that you recommend like the Custom Sealife or other?  <I have no hood brand preference... I'm a diehard DIYer> Does the AB hood come with the ballast? I think I seen that AB doesn't make 175watt bulbs.  <this falls under consumer research my friend... I apologize, but a three member crew spend hours daily struggling to keep up with the e-mail here and serve the greater good of aquarists in need. This I'll have to ask you to hunt down on your own> With the ballasts, if the ballast is rated for 250watt bulbs can I use 175watt bulbs on it?  <many aquarists have asked this.. I personally would not recommend it> I need to know the exact specifics because this is my first time and I do not want to mess up. Please give me more specific and detailed answers. Thank you greatly. <do look up a local aquarium society my friend where you can actually see and discuss the different set ups of several sort many aquarists rather than just take one man's biased opinion. Form your own intelligent and informed consensus from displays that you see that your like. If you cannot find a local club, participate on any one of the many message boards/forms where such a continuing dialogue will be more fruitful to you. Please forgive the brevity, but it honestly is an effort to help as many folks as possible every day through e-mail and this is more of a consumer question and somewhat of a personal preference when comparing two such excellent lamps. Best regards,>

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>

Re: Sorry . . . a question about lighting and bulbs Thanks for answering my last questions so quickly and thoroughly. I have one more question and that is it. Previously I asked (and you answered): But what color temp do I want with the daylights? I have no idea. I want to be able to have as many different types of corals as possible. The AH Supply website said to go daylight bulbs between 6,400 - 10,000. <Good advice, or at least I concur> Well there are a few options in that range. Which does what with regard to a) fish and coral health b) aesthetic pleasure of the viewer. <One actinic, the others... one 10,000 for now, and two 6,400 and next switch time go with two 10ks> Taking into account that my tank is 48 inches long and each of the 4 bulbs is only 22 inches long, the bulbs will be se up as 2 on each half of the tank. If I go with only one actinic bulb, it would be one of the bulbs on one half of the tank, will the tank look unbalanced with blue light? <Hmm, it will look a little (masked by the "white light" when both are on) and actually be unbalanced... but no worries functionally or IMO esthetically... Nice to not have an overall uniform appearance> Likewise when the daylights go off and the actinic stays on for awhile without them (you do this right?) will it be as beneficial, aesthetically and purposefully? <In my opinion, yes> For some reason I thought I should have an actinic bulb on each side and a daylight on each side. Likewise, if I go with only one 10,000 on one side and one 6,400 on the other, will one side of the tank look a lot brighter?  <Yes... a bit. I would place a 6,400 and 10k white on the one side (the right...) and the actinic and another 10k on the left> I promise this is my last light question about lighting. Thanks again for all your help. My co-worker/friend thanks you too for the lead to the brackish plant info. <Am out of time today unfortunately... gearing up for a trip... will write, post ASAP on return next month. Please remind me to add more to the brackish section if I slip up. Bob Fenner> Bryan Aalberg

Lighting Question Bob, I'm upgrading my lighting system on my 90 gallon tank. I currently have 2 x 96 watt power compacts and 2 x 30 watt (approx.) conventional fluor. I'm going to remove the conventional fluor. (won't fit with new setup) and replace them with 2 more 96 power compacts. My current 2 pc bulbs are both the CustomSeaLife SmartLamps which are 50% 10000K Ultra Daylight and 50% Ultra Radiant Actinic Blue. I have a variety of light dependent species in the tank from hard and soft corals to a clam. What 2 bulbs would you recommend to add the 2 I currently have, more SmartLamps, 10000K's or some of the lower (5000 - 8800K) bulbs or possible even the Actinic bulbs or would it best to use a mix?? Any help would be greatly appreciated. Thanks Phil in San Diego <For me, the two new lamps I'd make 6,500 or 7,200 Kelvin's... the rest I'd leave as is. Bob Fenner>

VHO or CF? Hi Bob, I am planning a 29 gallon tank for sp corals. I am especially enchanted with Acropora sp. I have a canopy and must make a decision on the best lighting to install. I am very tempted to go with 3 24" VHO tubes by URI. I would definitely use an electronic ballast (probably IceCap). But, in reading through many of your letters/responses, it seems that you might recommend going with CF's. The bottom line is that I want the sp corals to flourish. Please give me your thoughts as specifically as possible with regard to type, wattage, and spectrum of bulbs. Thanks, Trace <Actually (this adverb tossed in here to preface what may seem like contradictory information, instruction sets, but am not paid by the word...) I would like to suggest a 175 Watt Metal Halide for your 29 gallon... this size/shape system, being quite deep and more "square" in top profile than many tank models and your apparent desire to culture SPS corals like the Acroporids... that do best with intense lighting... causes me to make this my number one choice. I know some folks who would even undergo the electric bills and induced waste heat problems/solutions and place a 400 W MH on top of this tank...  And yes to my next choice being a Compact Fluorescent system... not as spectacular to view or as pretty as the MH possibility, but more light for less money (useful) than the VHO's... The MH can be most any temperature from 5,500 Kelvin on up, but wouldn't spend my money on any above 10k.... and do investigate whose lamps are currently longer lasting, and record the inception, replacement dates for same in your calendar/date book.... Guess that's about it. Bob Fenner>

New Lights Hi Bob (AKA Cutie-Pie) It's the newbie again. I know with 200+ Emails daily you probably hate these repeat patients!! <Hmm, no> My 92 gal. corner aquarium (up about 3 mos. now) with about 90 pounds of live rock is doing very well. Beautiful coralline growth and new things showing up almost everyday. I have been using the light fixture that came with the ALL GLASS AQUARIUM hood but with a used 30 watt Actinic 03 and a used full spectrum (Both Vita-Lite) I have wanted to upgrade my lighting since I began and I got the chance to buy two PC fixtures (2x55) this weekend. One came with new lights (ALL GLASS AQUARIUM fixtures) the other without so I ordered 2 55 watt Actinics to go in the second one. My question is this....Given these lights that I have now and with what the new ones are, what is my best plan to change them out?  <One new lamp this week, another a couple weeks from now...> I don't want to fry anything... I have just the 2 yellow-tail blue damsels, a domino damsel, a scooter blenny (he's adorable) and my Hawaiian feather duster that I wrote to you about before that lost his feathers and in fact, a new little guy has appeared. He's very much more shy than the first. Could that just be his age?  <Yes, assuredly...> I'm sorry, I think I might be rambling? <No worries> Oh yes the lights (really I'm not blond...;)...)Thanks for taking the time and Oh yes just one more thing. I bought this cute little live rock from the LFS because it had these cute little anemone things growing on it. Oops!!! Aiptasia!! At first it had about three small little clusters on it and some wonderful little red worms. Now it has about 8 (but still all on the original rock).  <Don't we wish our bank balances increased as quickly?> My question is should I get rid of the rock?  <I would take it out and let it air dry in the back yard a couple of weeks... rinse it in freshwater, and return it to the tank...> I love the little red worms, all my other live rock worms are white. Okay that's it I promise (for now) Thanks for your help and I remain your faithful groupie:)!!!!Joyce <Wowzah! Bob Fenner, the fish star!>

Lighting Questions <<JasonC here...>> Im also looking at a 3x175 halide system with blue actinic pc..... but it comes with has 5500k bulbs should I pay the upgrade fee for the 10k bulbs or is the 5500k bulbs ok? <<I would upgrade to 10K, is the MH that I use, I think 5.5 would be too blue.>> ....and also how high do I mount this set up ,12 inches above the tank?. is that ok? <<sounds good to me. Cheers, J -- >>

Lighting I have a 180 gallon fish and reef tank. It has been up and running for 12 months. I'm still unsure about the lighting requirements for my tank. I have 2 actinic 160 watt VHO and 2 daylight 10,000k 160 watt VHO. All of them are 72' . But the actinic are only on for 3 hours in the morning and then off for the rest of the day.  <Mmm, if it were mine, knowing nothing more than you have stated thus far, I would replace one of the actinics with a "white bulb" and turn the odd pair on an hour before, leave them on an hour after (but on in-between) the other "white" lamps> The only thing on is the daylight bulbs all day until the actinic come back on at night. Should I use more light during the day?  <Yes... all four lamps... with the odd pair on before and after for an hour or so... on timers> I was thinking of 1 or 2 metal halide 400 watt bulbs. I've been having a problem with brown algae and thought it was due to the lights.  <Only in part... Please read over the several Algae files posted on WetWebMedia.com> If you could give me some advice on the lighting and what you would use I would really appreciate it. Thank you very much. <Mmm, perhaps a cursory reading of the Marine Light, Lighting, many FAQs sections would serve you well here. Please: http://www.wetwebmedia.com/lighting.htm follow the linked articles, FAQs along. You will soon know what you want and why. Bob Fenner>

Metal halide, prob. halogen... Dear Bob, I want to add a metal halide fixture to my 30 gal. reef tank. My question is this. What kind of bulb? I have a fixture that was given to me that was used as an outside security light. I can purchase a bulb from my local electrical supply store. Is it the same bulb that can be purchased from aquarium supply stores? What's the difference? If the bulb from the electrical store can be used; what is the correct application? Besides cooling the fixture is there anything else that needs to be done? I've been told that UV needs to be blocked by adding glass or Plexiglas between the bulb and the tank. Anything you can do to help would TRULY be appreciated. Thanks >> Hmmm, be careful here, I suspect what you HAVE is a halogen fixture, not a metal halide... very different animal/source or propagation mode for generating photons. How much re these differences do you want to know... the physics? the practical outcome? The one you have makes lots of light (and heat) but very principally in the warm end of visible spectra... not very useful for aquarium use. The fixtures and lamps that are MH (metal halides) either come ready equipped with UV (and splash) shields... or are intended to be fitted with lamps that are coated in manufacture. There is much more to say... maybe take a look at light and lighting for marine systems articles I have archived at the wetwebmedia.com site. I will try to quickly get around to posting more, including jumps to useful sites. Bob Fenner

I need to get 4 bulbs (36" each) to go over my 125g fow/lr tank. but the choices are over whelming. There is Life-Glo, Power-Glo, Marine-Glo, 50/50 and on and on. The ads all speak highly of each bulb. Could you offer any suggestions? Thanks for your help. Michelle >> Gosh, I probably should just encourage you to keep investigating, or send you to my website (wetwebmedia.com) for archived articles on light and lighting for marine systems. As usual I have all sorts of suggestions: look for a mix of lamps, one or two actinic (the bluish looking lamps, when turned on) to run before and after your "white" lamps... which should be a certain temperature (5,000 K or higher), Color Rendering Index (CRI), 92 or higher, and do take a gander at "boosted" lamp and fixture technology... if you're going to keep the system a good long while, especially look into electronic ballasting. A real savings in the long haul (a few years). Do take a look at those articles on the WWM site, and the ones archived by various folks on AquariumFrontiersOnline and write back if you still are unclear about your options. Bob Fenner

I have a 170 gallon Tidepool reef which is running well; my question is if I change my 400 watt metal halide from the present 10k bulb to a 20k what effect will it have ? Also I am having trouble distinguishing the types of my Tridacna clams, any reference books or web pages that could help me identify them would be great. ROBERT WHITE >> Re the lighting switch... be careful here... if the system is shallow... which I'm sure it is... you may well "burn" many of your sessile animals... Either move the fixture up, shield some of the light output, or turn it "down" intensity wise for the first few weeks... and of course: keep an eye on your (esp. photosynthetic) organisms. Tridacnid clam i.d.... Daniel Knop has several worthwhile articles on the family of "giants" archived on the aquariumfrontiers.com site and my fave single article on i.d. and general bio. is Bruce Carlson's back in 4/91 in FAMA... and a nice rundown and pix can be found in Gosliner, Behrens, and Williams 1996 Coral Reef Animals of the Indo-Pacific... and unless my memory fails me, the folks at FFExpress have some of my pix of these bivalves in their site catalog and print ads... Bob Fenner, who says, give me specifics and I'll try to answer more specifically?

Help with metal halide lighting Hi Bob, I was hoping you could answer a question about this type of lighting. I recently came upon a 175 watt hanging type metal halide fixture with ballast etc.. I was planning on hanging this light above my 55g. I want this to keep some hardy soft corals, mushrooms and some pulsing xenia. I figured that this light would be good along with the large amount of natural sunlight the tank gets because of my girlfriends plants in the same room, I was planning on running it about 9-10 hrs a day. My main question is how far above the tank should I hang the light, I was thinking 9", and what spectrum bulb should I get, 5000K, 10000K etc., which would be best for these soft corals. I know this light wont' cover the whole length of the tank but I figured the corners would be a good place to start some mushrooms out. Thanks for your advice, Ehren Crumpler P.S. Thanks for getting back to me regarding my questions about the recent bill in the senate. >> Hmmm, well, first off, I'd like you to consider something other than the MH you have in question. Boosted or even regular fluorescents in number or better still a compact fluorescent would be fine functionally for the animals, depth of system you have in mind... But if you "must" go with the 175w pendant, do hang it a bit higher (a foot to a foot and a half) over the system for safety and use sakes.... Higher will give you less "punch" or photonic strength to the bottom, offset with better spread of signature, but you really want to discount the heat given off by the light and the likelihood of splashing the lamp.... and/or burning yourself while tooling around your tank... and Yes to the use of overhead sun... very good idea in many respects.. Just, do look into the other lighting possibilities. Less money to rig up and run, and better, more consistent results. Bob Fenner

I'm finally putting together the tank that I've always wanted. (50 gallons) I have one last concern though. I've been receiving various dissenting opinions on whether to get Dual 175's or Dual 250 watt MH lamps. The tank is 48" long. The lights will be mounted about 7 inches from the top of the water. I do not plan any actinic supplementation because I plan on utilizing 10k lamps. The bulbs will be mounted in polished aluminum reflectors. The Tank will house a few reef building stony corals  ( i.e. Acropora ) and a few of the more colorful tridacnid clams. So, in your opinion, would I be better off with the 175's or the 250's.  Thanks, Jeremy Keim >> If it were me, I'd definitely go with the 175's... and, of course I'll tell you why. First off the twin 175's will generate enough intensity... Second, they won't cause the water to boil! Really, the 250's at 7" away from the water will be dangerously hot... and the 175's by themselves will probably require that you use a chiller... Almost lastly, the 250's will boost metabolism too much... shortening lifespans, granting you too small margins if something should go wrong (like a pump or chiller going out). Then there's the cost of electrical power... not worth the extra watts consumed in my opinion.  Your clams and Acroporids and other photosynthetic life will do fine on the 175 watt Metal Halides... without frying. Bob Fenner

Duro-Test Vita-Lite Supreme lights I read your article on WetWebMedia where you recommend Duro-Test Vita-Lite Supreme lights. Do you still believe these are the closest lights to natural sunlight? Are these power compacts or regular fluorescents. And if they are regular fluorescents do you have a recommendation for power compacts? Thanks, >> These are regular (T-12) fluorescents... and they "were" the best available, most appropriate technology... no longer... Compact Fluorescents are the current winners of that title. Producing the best (functional) amount of useful radiation per kilowatt hour energy, including initial and ongoing fixture costs... and producing little waste heat. Bob Fenner, who agrees that he should go back and place a "written date" on each of the pieces on WWM...

Hi Bob, I've recently found www.ffexpress and your column. Too bad I did not find it sooner, I would have spared the lives of many, many fish. I have a 30 gallon tank (12X16X36), live sand (very recent change) and am currently building up my live rock collection. My filtration system includes a US Aquariums protein skimmer, Whisper 3000-wet/dry trickle hang on filter, and two power heads for additional circulation. I use RO/DI water in my tank (another recent change). My question revolves along lighting and live rock. Up until reading your column, I was unaware that live rock needed strong lighting. I now believe that my current 18' 15-W 50/50 light will not be strong enough to sustain the live rock. I am contemplating upgrading my lighting system to a dual strip, 36' fixture that would provide 60 W of lighting. Is this enough wattage for the live rock? If so, what type of bulbs would you recommend. I am saving my pennies for a 100-125 gallon reef tank in a year or so, and don't want to spend mucho dinero on lighting for my 30 gallon. Thanks Bob!!! David Hacker <Thank you for sending this well thought out and personal note. Yes to more lighting and if you're going with conventional (T-12) lamps... the two 36 inchers... do make one a higher full spectrum white (temp. of 5k plus), and one an actinic variety... and if I may kibitz, have the actinic come on and go off an hour before/after the white (on a timer...). If I may go beyond your query (okay, just try to stop me!), I'd encourage you to even consider another type of lighting system entirely... the power compacts. They produce more useful light per kilowatt power, are cooler, and brighter then other fluorescents... more on light, lighting of marine systems at www.wetwebmedia.com Bob Fenner>

Lighting? Lamps and fixtures Hello Bob, I have a 30 gallon tall setup w/ eclipse II and I was wondering what lighting would be best for propagating the growth of my live rock and inverts? I do not have the ability to use VHO, metal halide or power compacts. What do you think would be better? 10,000k and 03 Actinic, 20,000k and 03 Actinic or 10,000 k and 20,000 k fluorescent? thanks a bunch, Ben >> In my opinion... and you know many other folks will state otherwise, the first choice, the 10k and O3 are best.... for looks and function overall... Now that bold statement being made, there are "live rock and inverts" mixes that would quickly change my mind. If/when you find yourself more interested in small polyped stony corals, tridacnid clams... or perhaps boosting the growth/metabolism of other less-light demanding species... But for now, and overall... the 10k and 03. Bob Fenner

Hi Bob, what is the difference between 10,000 daylight and 20,000 daylight? >> Let's see if my old High School teaching of Physics abilities are still with me here: the "color temperature" of a light source is an approximate measure of it's relative emittance relative to a heat source of Hydrogen burning at that temperature... Hmm, well, how about this analogy instead? If you could "look" at the Sun, with a filter that would only allow you to see the gasses there combining/falling apart at the 20,000 Kelvin temperature, this is the light a similarly rated lamp would look like... Any better?  Bob Fenner

Aquarium lighting I have a 125 reef tank with lots of corals and fish. For the past year I have used 4-40 watt fluorescent lights on the tank. (2-actinic, 2-10,000k) I have been given a VHO ballast from a friend and am thinking of setting it up.  My plans are to use the VHO along with my fluorescent lighting. I only have room for 4 lights in my canopy. Should I use 1-VHO-10,000k, 1-VHO-actinic, 1-40watt-10,000k, and 1-40watt-actinic or 2-VHO-actinics, 2-40watt-10,000k?  Or do you recommend another setup and how much better will my corals and fish react to the new lighting? Thank you for your help. Kris >> Thank you for writing... If it were me, I'd go with the first configuration... and if you don't invest in a dimmer mechanism, do consider leaving off the regular output lamps for the first month... and/or covering the VHOs with some strips of aluminum foil to cut back their intensity for about a month... You're smart to ask this about the lighting change... many people literally "burn" their photosynthetic life consequent to these upgrades. Bob Fenner

Substrate cables (again!). also bulb question Hello again Robert! Thanks for your reply to my messages. So, in a nutshell, regarding reef tank substrate heating... would you or wouldn't you? I don't mind being labeled "experimental," but on the other hand I'm certainly not made of $, either. Thanks! <Likely not... too much money I'd rather spend elsewhere... not that much perceived potential gain for me> Now for a more technical, less theoretical question (groan...please bear with me)--- Am thinking of the best way to illuminate my Corner 92 (this is a triangular tank). For my planted discus tank (also a triangle) I use various CF striplites arranged across the top, longest in front back to shortest (12") @ rear (all 6500K) and also a simple NO plant bulb (8500K) that is run longer than the others for a sunrise/set effect (the cardinals appreciate this transition greatly).  <Neat> All this is mounted to a brace on pulleys that can be raised/lowered to allow access into the tank, and it works very well, but (and please bear with me)...... <Okay, good idea on the pulley... have even seen electrical-motorized ones on big, rich folks set-ups...> I want a halide for the SW tank! So here is what I plan to do- run a 65W CF down each side in an inverted 'V' (I will construct a custom brace for this), and have a MH pendant (spot) in the very center of the tank, above where the clam will live someday. The two fixtures will be hung separately, so I can adjust their heights independently. So far so good, but here is where it gets technical... Firstly, I want a sunrise/set effect using actinics, arranged in the 'V'. I could use CF bulbs for this but that sure seems like a lot of watts for just actinics-- maybe NO tubes would be better here (what do you think?). <I would maybe make one of the lamps an actinic...> This setup would have only a 65W above each side (plus actinic) <Mmm... where are these other lamps coming from?> above where most of the LR will be. As I hope to someday have an anemone at the rear corner up relatively high, would this be enough light (as the halide won't shine here)? Or should I use two 65W each side (I guess then I could have one each be a 50/50 for the transitions, but 130W doesn't seem like it'd be too subtle!)? Or two 65W each side plus NO actinics (YIKES! How many bulbs/timers is that!?!)? Plus the halide! <I would double the 65 watt fixtures... and have at least one of the lamps an actinic variety... (Have that odd-pair come, stay on and go off an hour or so ahead of other lighting)... and place the anemone thereabouts.> --(deep breath)-- Secondly, with all these different bulbs, the possible color combinations are huge! Of course, I'm looking for the most attractive one without having to actually purchase the bulbs to play around, so... A) What color halide would you recommend (this probably won't hardly be used until the clam arrives, but still I want to have a plan)? I was thinking 6500K or 10K. <Me too... or anything in-between these values> B) What CF temps would you say down each edge (maybe 1@50/50, 1@8800) Please have a good think about this--but don't drive yourself mad like I'm about to. <No need to drive any further. Am parked. I like the 8,800 K's> --(whew!-that feels better)-- Thirdly, should I run a nightlight somewhere over this thing (or will the residual photons be enough-ha!)? <If it's dark in the area, a night light is a very good idea> This tank will have a tempered glass "lockdown" lid to contain an eel, so this will decrease the lights' penetration some. Now, yes, I know that I'm probably making this harder than necessary by wanting a halide, that I could simply re-do what works on the discus' tank with all CF strips, but Bob- I love those little MH light ripples! (but to the point of insanity?...YES!) Thank you very much! from Erik (did I write all this?) Nelson <Yes... do "practice" with how hot the MH will make this top... keep it clean, wiped down regularly. Bob Fenner>

Re: substrate cables (again!). also bulb question WOW! Now that was a fast reply! So, it sounds like you're advising-- no to the NO actinics,  <Actually yes to one actinic lamp (the "odd pair")> yes to two pair to 65W CF, each pair consisting of a 50/50 & a 8800 (the 50/50's being used as the transitory), and a (175W?,250W?) <The 250 Watt should go... wouldn't try any higher> MH? Good!-- I know of a retrofit that includes those two CF temps, plus individual cords for ea. bulb-- sounds like that's just the ticket for my situation! Thank you! P.S. Do you think that halide shining onto the glass will be a big temp problem i.e. w/o surface evaporation (both the eel and my little kids necessitate the tempered glass lockdown-----I am sure they don't mix). <Will be very warm... Would go with your glass-shop's recommendation. Bob Fenner>

Lighting The Way!  7/10/03 Hello,<Hey, you've reached crew member Phil tonight!> I have a 75 gallon saltwater fish only tank with no live rock.  I would like your suggestions as to a fluorescent bulb that will bring out the colors in my fish and dead coral.  Something to enhance it so to speak. <I would say something in the bluish color, an "actinic 03" bulb would be nice.  IMO, it will really make the tank/fish look great.>  Thank You.<No problem, good luck!  Phil>

Lighting 8/9/05 Hi Crew     I was wondering which of these fluorescent bulbs are visually brighter the Coralife RO 10,000K or the 20,000K? Thanks <The perception of most folks is that higher incandescence (K rating) appears brighter. Bob Fenner>

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