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FAQs about Light and Lighting for Marine Systems 1

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Related FAQs: 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 19 & FAQs on Marine Lighting: Fixture Selection 1,  Fixture Selection 2, Fixture Selection 3,  (incandescent, fluorescent, MH/HQI, LED, natural...), Lamp/Bulb Selection 1, 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

Odyssea Light Fixture  - 3/1/2006 Dear crew. I am setting up a 180 gallon reef tank and am wondering about lighting for it. Since I'm on a limited budget I was looking for cheap light fixtures and discovered at www.aquatraders.com < http://www.aquatraders.com/> they have 72in 785 watt MH, pc fixtures for $400. The fixture has 3x 175 watt MH, and since recently it has 2x130 watt PCs instead of 4x 65 watt, but in the end it has the same wattage. I couldn't find much info at all on this lighting from various other sources. I was wondering what you think about getting this fixture. I'd rather get a higher quality fixture and pay more than getting a low quality fixture cheaply. P.S. would any species of SPS corals survive under this lighting, and if so what species? Thanks for responding to previous questions I had and for this one. Thanks again. Marcus.   <As with most all "gear" questions, I'd look/ask about on the various specialized BB's re actual user experiences in a broad stroke... Reef Frontiers, ReefCentral, Reefs.org... Compare notes re customer service, useful life, energy consumption per function, alternatives, applications. Bob Fenner> Advert., and/or looking for lighting for someone else  11/9/05 Hello, Some of my clients are searching online for custom lighting. My job is to find one place to send them to for specific markets. I'd like to discuss an arrangement with you. <This sort of information is posted/archived on our root web... which is searchable, indexed... Bob Fenner> Please contact me at your earliest convenience. I will be in today (Tuesday) from 8:00 AM EST to 8:00 PM EST. I will also be in tomorrow from 8:00 AM to 8:00 PM EST. You'll need to be at your computer when you call me. Please call when you have a few minutes and I will a demonstrate how you would benefit from what we do and b answer any and all questions you have. Best Regards, Jason Baselice Business Segment Analyst, Star Position <No thanks>  

Marine lighting question 8/28/05 Hello Bob, This site is great and very much appreciated by new guys like me who um....really don't know what they are doing. Anyway I "am" a new guy, I have a 90 gallon saltwater setup with 60 lbs. of live gulf rock, 1 yellow tang 2 false percula 1-6 line wrasse clean up crew+skunk shrimp small group of pumping xenias I am running a pro clear aquatic wet/dry sump 125 w/ a pro clear aquatic in sump skimmer (which is producing about a half a cup of dark muck per day). Also I am using 2 part Ocean's Blend calcium and ph/Alkalinity... about  every other day. Any way my question is about my lighting.. as it stands right now I have (2) 65 watt PC 22 in. and 2 Coralife 40 watt actinic bulbs. I have been taking advice from my local store, and of course I get different suggestions and answers from different employees about how much or what kind of lighting I  should purchase. <Good> Next month a friend of mine is moving quite far from here and  he will be selling me everything he has in his 55 gallon thus including 60 lbs.  of live Fiji, 1 leather, 1 brain coral, a big group of pumping xenias, big feather duster etc. well I want to make sure I have appropriate lighting for   these new corals, I was told I need 2 150 HQI bulbs and 2 PC actinic bulbs. The   setup my local dealer was trying to sell me today was in the mid 700.00 range.   Though it sounds great, I just don't have it this time around, could I possibly  add more pc's or something? Any help is always appreciated! Thanks for listening, Paul <Mmm, could add more boosted fluorescents... but won't have the intensity to "do as much" in the way of growth, color in this depth of tank/water as using metal halides... you don't need the actinics... More on all these choices, issues posted over and over on WWM. Bob Fenner>

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> Water leak in ballast <!!!> 8/5/05 Hey everyone, <Nilesh> A month ago, I had a leak from my external skimmer onto my ballast casing.  I have three 175w MH bulbs with 3 ballasts encased in a box.  One of the lights no longer works.  Over the past month, I let the ballast dry out but it seems like salt is shorting the ballast. <! Unplug this unit! Very dangerous!!!>   What is the best way to remove this salt.  Do you think vinegar and water?  I'm hoping that I can get my bulb working again. Thanks Nilesh <Not likely economically repairable, but you might try sending it back to the manufacturer or distributor (their name, probably address is posted somewhere on the product)... Ballasts need to be carefully protected from water, heat, dust accumulation... mounted somewhere away from such influences. Bob Fenner>

Lighting for 92 Gallon Corner Tank 7/12/05 I am upgrading my 55 gallon aquarium to a 92 gallon bowfront corner reef ready aquarium. My question has to do with lighting. My LFS assured me a 36" light will fit the canopy. I am thinking of going with metal halide lighting versus PC. What would be an ideal wattage as far as the metal halide and power compact combo? Thanks so much for your help. J. Howell <... depends on the type of life you intend to keep, what you "want to do with it"... Please read here: http://www.wetwebmedia.com/marine/setup/lighting/index.htm and the linked files above... till you understand. 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>

A Question of Lighting I have a question regarding lighting for my salt water tank. Currently I do have 3 fish and some corals and they are not looking as well as they should (the corals). Chemicals aside, I think my lighting may have something to do with it. I have 110 W of PowerCompact lights. I have a 65gal flat back hex, so my dimensions are a little weird. 48" long, the flat side is 9 3/4" then it angles again 9 3/4", and it is 20" high. Would you recommend I switch to VHO, add more wattage or what? If I add another light 36" it sits in front and I have to remove the light every time I need to feed them etc.....I am also considering building a canopy for my tank. Does that alter the amount of wattage needed? Would you recommend a canopy or not? Thanks for your help. <Please reply with what corals you currently have and what else you intend to keep. All discussions about proper lighting for photosynthetic inverts has to start with what their requirements are. -Steven Pro> Victoria

Lighting Upgrade Dear Bob, My present tank is 60"L x 24" W x 30" H housing only softies due to angels and BF's lit by 6 x 40W NO fluorescents. <Okay> I have two options of light upgrade, 2 x 150W MH or 8 x 55W PC. Taking into consideration that I do not plan to have SPS, which would be a better option. <A tough one here... both could be made to work. I will opt for the metal halides here though... due to the size, shape of tank, my personal "looks" preferences. Will be spectacular. Bob Fenner> Regards.

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>

20 Gallon Lighting Question Hi Bob, I really have enjoyed reading your words of wisdom on the WWM site. I have finally come up with a question of my own. I have a 20 gallon tank with water volume that measures about 22x16x16. Right now I have 2 maroons, 1 cherub angel and a handful of hermits with about 15 lbs of live rock. I plan on adding some more live rock and would like to add an anemone for the clown and maybe some other "low light" corals. I have been looking at the Custom Sea Life PC 15 inch light hood to add. This would give me about 64 watts of light for the tank. My question is whether this is enough? <Mmmm, is there some way I can talk you into a larger system? A twenty is inherently too unstable... a bad risk for these additions. The kind, strength of lighting per gallon is about right however. Thank you for writing. Bob Fenner> Thanks in advance for your assistance, Tony Jopling

Re: 20 Gallon Lighting Question Thank you very much for your extremely fast response. Yes, you could easily talk me into a larger system, however my wife (and my soon to be born son) might have something else to say about the expense of a new system. <Thought children couldn't talk for a couple of years...> We do however have plans to purchase a new system in the future. Probably something more like a 40-50 gallon system. <Ah good> Something I think I will have to begin working on very slowly. For now we are going to add a Bak-Pak and do some improvements to the lighting of our current system and then we can follow up with some simple corals. So now I have another question. I just purchased the "handful" of hermit crabs I mentioned before. I have 3 blue leg and 5 red leg crabs. I am not sure if there are any additional needs they have as far as food goes. My tank currently develops brown algae fairly well. Does that provide sustenance for the crabs?  <That and "scraps" should suffice> I am afraid I am fairly ignorant on their care. Thanks again for the wonderful resource that you are providing. Have a wonderful Holiday Season! <Peace to you my friend. Bob Fenner> Tony Jopling

I am about to convert my fish/live rock tank to a reef tank and would like your advice on lighting. I have a 150gal which measures 72"x24"x24". I currently have 3x160w VHO's. 2 white, 1 actinic. My LFS has told me my current lighting is sufficient for all coral types. I am concerned about temp build up. My tank currently runs at 82 degrees. I had thought about using a retrofit kit 6x96w PC's or metal halides/PC combos, but don't want to add a chiller unless I really have to because of the noise/cost. I currently have a very nice oak hood from Tenecor which I'd like to keep. If you feel the lighting is sufficient should I consider Ice Cap ballasts and fittings to try to reduce heat ? My guess is more intense light will make my temp problem worse ? Any advice you can give would be great. Thanks. >> Thank you for writing, and providing such complete information... what you have, what you want to do with your system. Switching to the electronic ballasts is one very good possibility... for reducing waste heat, improving your lamp performance and functional lifespans. If you didn't have the current VHO's there would be no doubt how I would go, with the Compact Fluorescents in your case, size, shape of system... and lack of interest in a chiller and all that goes with it. And considering how much the ballasting costs, I would switch to the CF's, with 1/3 maybe as actinics, and at least one third as 10,000 K "whites", maybe the others at a 5,500 K area.  The current lighting is fine for many types of corals (soft, most gorgonians, Zoanthids, Corallimorphs...), but not SPS like Acroporids and not many of the larger polyp stony corals, IMO. Bob Fenner

I have a question about lighting my 90 gallon reef tank. As of now I have 4 standard 40 watt bulbs and one 30 watt over it. As far as corals go I only have a few polyps which I place as close to the light as I can and they seem to be doing fine , even growing and spreading. I would still like to move up to four 55 watt PC's but I am concerned with the amount of heat that they produce. With my standard fluorescents I am barely able to keep the temperature at 79-80 degrees , I am concerned if I put PC's over it, the temperature might go up even more. I know the extra light would give me more versatility with keeping corals but if they heat up my tank too much I don't know if it would be worth it. How much more would the PC's heat up my tank and would it be worth it to get the extra 60 watts over the tank? Not to mention $300-$400 dollars is a lot of money for an extra 60 watts. Any advice would be appreciated , thank you. >> The power compact fluorescents actually won't heat your water much... probably not even noticeably more than your current lighting arrangement... It takes a lot of energy to raise water temperature. If you find that the heat is too much period in your system, I would encourage you to do two simple things about it: switch the lighting regimen to having the lights on more/all at nighttime rather than day, and look into passive and active venting of the hood. A simple muffin fan cut into the electrical supply to the lights (so it runs at the same time while they're on), or just some holes drilled into the top/sides of the top will lower the temperature a few degrees different. Do agree with you concerning the net gain from the proposed vs. present lighting. If it were me, I'd switch to four 96 watters... FFExpress has them on sale now, I think for $421... or thereabouts. If you think you might go with more small polyp stony corals, giant clams, I'd invest in these instead. Bob Fenner

Light fixt. Your Q&A have been an invaluable source of information. I have a 155gal mixed reef with appx 160 lbs of live rock, 1 finger leather, a couple of polyps, cabbage coral, long tentacled plate coral, and two anemones, as well as some fish. I am running two 250 watt metal halides in a custom hood (12000 Kelvin bulbs), and the tank doesn't seem bright enough, what would you add, if anything? >> Hands down choice for me would be retrofitting your system with some compact fluorescents. Take a look at the sort of technology FFExpress.com offers: a mix of lamps of 6700 and 7100 daylight and actinic... separate dusk/dawn controls... this is what I'd get to add to your MH's... I would definitely go this route, and not the upgrade to 400 watt metal halide lamps, or any other type/temp. of fluorescents. This is the best way to augment what you have to get the best looks and function from your system lighting-wise. Bob Fenner

Light Meas. have a question about a light I found in my garage. we've had it for a couple of years and it doesn't get used I think it came from a race track. its output is incredibly white and bright, however I have no idea what kind of light it is. the fixture is large and rectangular (approx 6x10), while the bulb is only a couple of centimeters in diameter with a length of a couple inches. Halogen? If you know about it please advise, if the bulb is appropriate as far as K temp and PAR, might use it on a propagation tank.  thanks again, Chris <Hmm, at this juncture, becoming a culturist, and advanced aquarist all the way around, I would encourage you to buy a PAR meter... Halogens by and large actually don't produce much useful wavelengths of light per kilowatt energy consumed... but about the only way I've been able to convince folks of this is the meter route... At this point, the cheapest PAR can be gotten by way of Compact Fluorescents (up to 24 inch or so depths for most fixtures, lamps) and metal halides (for most deeper systems), not HQI... Bob Fenner>

I have been told that I need special lights for live rock, as of now I have 4 - 48in. from the hardware store, 3 normal warm lights and one blue sunlight light. will these work for now, or do I need to get coral life lights, I plan on getting some new ones later when I go to a reef tank. thanks >> You can use most any bright light source, but full-spectrum fluorescents of a warmer temperature range (measured in degrees Kelvin) of 5,000, and a CRI (color rendering index) of 90 or more are needed for really healthy growth (useable wavelengths of light are at question here)... You don't mention how big, deep a tank, or how much, what type of live rock... Maybe take a look at the Marine Lighting materials stored on my site: Home Page for much more detail, input. Bob Fenner

Hello: I've heard you talk about reverse photoperiod in regards to lighting . Could you please explain this briefly ? Thanks, Jill >> Reverse photoperiod refers to lighting regimens alternating between a main and sub-system like a sump/refugium... One being on while the other is off... the benefits of such an arrangement include a stabilization of water quality, dissolved oxygen, algae reduction... Bob Fenner, who must always remind himself of the enormous amount of cryptic and arcane terminology and verbiage in our interest, and thanks you.

New line of questioning....I know I need to upgrade the lighting on my tank again...I should have learned by now that there is no easy way to cut corners in salt water...right?  <A few, but not many> Well, On my 92 gal corner aquarium we have about 110w in Power Compacts and 60w in a regular Fluorescent. (in each 1 actinic bulb, one day). That totals 170w....well, through FFE. I see that they carry a 36" power compact in hood, 384w for $529 and a Metal halide/ power compact prism with 306w for about $439. Could you please advise me on which to go with?  <I'll try> I really don't have the money to spend, but you know all of the trouble that we are having with the mantis, and the Cyanobacteria etc....I don't want to "mess up" again and have to spend even more to fix the new problems. <Agreed... and the amount of lighting is directly tied in...> I have described the top of my tank to you before with its odd shape there is no hood. I have merely a cover glass with the lights in their own hoods (the one has its own fan) on top. When I switch to the new lighting it will no doubt not cover the entire top of the tank. Do I need to be worried about the light escaping around the sides of the ABS hood through the cover glass?  <Not really, unless it annoys you.... there are advantages (functional) of reflecting the light down, into your system though... hoods, contact material you can buy, install... even (for non-MH... they get too hot), Mylar-reflectorized acrylic that is easy to cut/have cut into panels that can be fashioned into light hoods/niches...> Please be honest. Should I hire someone to build some kind of reflecting hood that will cover the whole cover glass? <If you don't have the time, tools, materials, expertise... sure (I don't do much work on my old (Hey, they're paid for) cars)... No worries... Or you can fashion one out of wood... and maybe rig up a trellis-like arrangement for lifting it up, out of the way when you want to get inside the tank...> Not too much light "escapes" right now due to the fact that I have the two ABS hoods up there...but switching to only one may be a different story. Also, one more small question...how do I make the switch less dramatic for the fish and algae problem?  <Phase in the number of new lamps, hours on... over a few weeks time.> Maybe by only turning on half of the lights for a week or so, and then three lights, and then all four? Is that even possible?  <Sure. There are timers, dimmers... or the manual route> Are there four switches on those things? Gee I wish we had some intelligent marine tank specialists out here!!!! Thanks again. I look forward to your response as usual! RT :)  >> <Sure, and thank you for the swimming Tang download. Either the CF's or CF and MH combo will do well on your size, shape tank... I am inclined to suggest just using the CF's as these will do the job and present fewer technical and problematic possibilities (the MH's are HOT, and need to be situated higher above the tank... produce waste heat that needs to be dealt with... And do produce copious amounts/intensity of light... but maybe for types of organisms you never intend to house... like SPS corals, Giant Clams.... If it were me, or you were my customer, I'd stick with the CF's... Bob Fenner>

180 salt fish tank setup, fixt. I have just purchased a used 180 SeaClear tank and am working to set it up. My question is about lighting. The tank will have fish and live rock but no inverts. I have gone to many fish stores over the last week trying to narrow my lighting choices down but have become more confused. Some say that 2 4' fluorescence will do, others say that I should go with the compacts. Then they talk about the blue and white lights and also weather on the compact lights to go with 2 36" with 2 bulbs each or 4 bulbs each. I am totally confused. I am going to have a canopy so the lights can be mounted. And I want the tank to be bright but not blinding. Any help you can give me would be appreciated. >> Good to hear of your going with building/buying a canopy... the hoods that come with SeaClear's tanks are inadequate... Do understand the many different opinions you're getting... Who knows how long you might keep this 180 just "Fish Only"? Also, depending on the setting... two Regular Output (RO) or four might be too dim for your enjoyment... For me, I would look into at least four RO to boosted (High, Very High) output fluorescents... or step up to the plate for the Compact Fluorescents (CFs)... and not worry too much about the "blue" (aka actinic) lamps for now... you can buy them later... or just get one or two lamps in this spectral/temp. range if you intend to start with, or soon add live rock... or any photosynthetic life... In either case fluorescents come in different, specified temperatures... and I would go with lamps that are at least 5k in temp... and likely some in the 5 and 10k ranges... take a look around at retrofitting this gear yourself, btw. FFExpress.com sells the parts for the DIYer. Sorry if I'm adding to, instead of erasing the bloat of information here... Maybe take a look at the Marine Light, Lighting sections stored at the URL: www.wetwebmedia.com Bob Fenner

Lighting, fixt. Hi 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, fixt. My Tank is 72x18x18, and I currently have 2 36" twin tube NO lights for the tank. It is a fish only with about 45 lbs. of live rock ,11 fish( 3 tangs, 2 clowns, nigger trigger, damsels), 2 Condylactis anemones, Feather duster and 2 shrimp (banded coral & cleaner). I would like to try soft corals, but I know that the lighting must be upgraded. I want to go metal halide but I am worried about the heat, (no chiller in budget). I have been told to use 175w 10,000K. Are pendants ok? What about fluorescent lighting? I need help? Also, is it cheaper to build myself? Thanks. >> Hmm, if it were me, I'd leave off with the metal halides ideas altogether, and either add more regular to boosted output fluorescents, or if little room, and/or desirous of more intensity, look into compact fluorescents instead, in addition. Take a look at FFExpress retrofit products for these: yes, you can DIY. Am a bit worried about the Niger Trigger in this mix... it will eventually go after your shrimps, feather duster, and probably your clowns... Bob Fenner

Hi Bob, First of all, I would like to tell you that your column is the best I've ever read. It's too bad that people like my husband, that only speak Spanish, cannot benefit themselves with it, like they would like to. I hope that one day we can be able to find information in our language. I would like for you to take in consideration my constructive critic which will give you the success in being the first in writing a column about this hobby, offering your readers the option on choosing the language they prefer to read it in. <Please do look into a language translation program... they are easy to use, and work quite well> The reason why I'm writing is because my husband plans to set a 55gls (long) with live rock for hard and soft corals. Our question is, which type of lighting is the most adequate for this, taking in consideration that he wants something that is effective and at the same time affordable. <At a minimum four foot (40 Watt) regular output full spectrum fluorescent lamps and fixtures for your four foot long tank... Better would be two to four VHO (Very High Output) fluorescent lamps, or two or four Compact Fluorescent lamps. Make one or two of these actinic types, and put the last on timers to come on and go off before and after the "white" lamps about an hour each way>  Even though we have a 110gl fish only, and we want to be sure that the lighting that we are using for the corals tank is the best. Any help on this will be appreciated... Nibelma and David PS. Excuse my poor English, and hope you understand me >> <Your English is perfect Senora, gracias usted, Roberto 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

Lighting and setup  I work at a pet store and I try to provide as much information about saltwater setups and fishes. I read your section at FFExpress everyday just absorbing the information. Here is my question. At work we are competing with another pet store almost across the street with saltwater fishes and reefs and etc.. We are setting up a 125 gal reef tank. The owner of the store wants it to be the main attraction of the saltwater fish section. He put me in charge of it because I am the only one with any experience in saltwater fish. Anyway, I have basic knowledge for corals , just like polyps and anemones, but not any hard or soft corals especially pretty show ones. What sort of lighting do I need to get for the tank, he wants to use a wet/dry system, so maybe other people will look at it and buy one. What are some easier corals, most likely to live, that are pretty or unusual to look at and what are some good fish to put in there. I want to put some Banggai cardinals, I love those little guys but when I would feed them, a lot of the food would be gone before they got a chance to eat, so what are some other fish I can keep with them that are reef safe. When people come into my store, if I cant help them or don't have a clue, I send them to your webpage to ask you, I have had some nice comments about your response. thanks for the help, Mike >> Thanks so much for writing... And get ready with the big pot of coffee for some "late night" study... Do your store, the hobby, and yourself a giant favor and get/read (they can/should become "store reference copies" Volumes 1 and 2 of Sven Fossa, Alf Nilsen "Modern Coral Reefs", and Charles Delbeek and Julian Sprung's same number of tomes "Reef Aquariums"... and read them carefully....  You are soon to represent not only your store, but the industry's best and brightest information/presentation on what the marine hobby has to offer.... And from these questions.... You're not ready! If it were my shop (spent 14 years "on the floor" retail, started, helped run a corporation that had stores...) I'd set-up the 125 with both Metal halide pendants AND some compact fluorescent actinics... Easier corals? Start with some of the Euphyllias (Anchor, Frogspawn...)... Avoid buying, displaying tough-to-keep species like Gonioporas ("flower pot"), Elegance (Catalaphyllia) Corals....Fishes? Where to start? For when you're on the Net, take a look through the selection articles and family/genera/species accounts I have archived at www.wetwebmedia.com for a quick introduction to what is available, best... and what to avoid... Pay especial attention to the sections: "The Best Livestock... for Your Reef/Marine Aquarium" (unpublished book sections). Thank you for your kind comments, and involvement in "our" interest! 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

Regarding your response to the lighting question yesterday, I too have a 55 gallon tank that is 48" long. You indicated that you like a single MH 175 w with 2 regular actinic bulbs. When I look in your catalog I see the light is 24" long. Is this adequate for a 48" tank? Also there is a fan cooling option. Is this something I should get or does it not really matter? I am not familiar with these lights. Do they hang above the tank? I assume they are too hot to sit on top of a tank with a glass cover / shield. Thank you for all of your information. >> Hmm, the twenty four inch lamps would be okay... if one is positioned all the way to the front right, the other all the way to the left back... and no to a fan if you're going to mount the metal halide high enough, leaving the top mostly open to allow light through... I would not enclose a/the metal halide... and would leave off with as much of a glass or other cover... instead fashioning a canopy type of arrangement with some front and back panels to affix the actinics/fixtures to. Bob Fenner who wishes he could draw an image of this...

Green water I'm having a lot of problems with the water in my tank turning green even with changing the water completely it still turns with in about 72 hours I have no plants in the tank but I do have two large coral rocks and both aeration and filtration. I do leave the tank light on all the time could this be the problem im not sure what else to do Jason >> Yikes, do get a timer and have the light off a good part of the night... regularly... and look into some live rock, and/or a bit of macro-algae... all this should clear the tank up in a couple of weeks. Bob Fenner

Will you please give me a name and wattage on types of light I can retrofit and where I can get it for the RR Oceanic 135g fish only Thank you for your help .New aquarist  >> For what sort of livestock? For what function? To keep them alive, just see non-photosynthetic organisms, like fishes, when you want to? To maximize growth of giant clams, stony corals...? Do a little more digging... take a look at the marine aquarium lighting and light articles stored at www.wetwebmedia.com There are many options... for me, I'd fit in some compact fluorescents in the 135... but the number of lamps/watts, and their types (actinic, different temperatures of the "white" lamps) would vary depending on the types of life and function YOU have in mind...  Bob Fenner

Lighting I have a question I'm starting up a reef tank and I was wondering what would be better on a 30g 192watts or 284watts  thanks, David  >> If you're just starting, I would go for the lower wattage for sure... "Boosting" a system photically is a dangerous and involved enterprise... Everything happens faster: waste heat production, algae problems, injurious interactions between photosynthetic antagonistic species (there's a bunch)... Go with the lower wattage... this is enough light to keep any type of marine livestock... Bob Fenner

Lighting With the high cost of Metal Halide is it possible to light a reef tank with a Mercury Vapor light. I have an old book published by Tetra press that suggest that Mercury Vapor can be used it just needs to be supplemented with Actinic blue lights. Before I switch to a new lighting system instead of fluorescent and it's expense of changing tubes every 6 months I'm trying to explore different options. >> I would not go the mercury vapor route... though these lighting types are in use in some places in Europe... I don't care for them... for the incomplete wavelength issue you mention as well as their appearance... Save up for MH, and/or investigate the next generation of functional/aesthetic winning lighting technology: Compact Fluorescents... all the looks and intense full spectrum... at lower initial and operational cost... with negligible waste heat...  Bob Fenner

Lgt. fixt. Hi Bob I just read your book which was fantastic for a beginner as myself. I have a 67 gallon fish only which I am slowly converting to reef. I plan to keep soft corals but I do not know what the future holds. I need to buy a metal halide hood. I want to buy the hood once so I don't want to spend the extra cash to upgrade in future. 48 long, 16 wide, 20 deep. 2.5 inch sand bed. either 1) 2 175 5500k with 2 NO actinics extra fan plan to upgrade to a 10000k bulb for the look later on. 2) 2 250 6500k Iwasaki with 2 NO actinicsextra fan also can get the 10000k in future. For the moment I don't know my goal but I love clams and soft corals. My worry is that I might not need 250 watters? its 20 deep can 175 watts be good enough, I am worried about overheating the tank with the 250 etc...or spending money that does not have to be spent. might get a 24 deep in future. 48 long, 18 wide 24 high= 90 gallons, will 175 be ok? or should I get the 250 from start. Also all I want is a bright white look to the tank, not to yellow, green or blue. Which combination will do this white color look? Thank you Bob , loved your book. >> Thank you for writing... and if you don't mind, after you've obviously done quite a bit of research already... I'd suggest you reconsider your options... and take a look at the possibility of compact fluorescents for the 20" tank... something in the way of two lamps in the 10k temp. range... which brings up the MH idea... the higher Kelvin rating the brighter white appearing... and if you do go with the 250's you're definitely going to have to get a chiller.... so I would: 1) Get CFs... or secondarily: 2) The two 175w MHs or lastly... with a chiller and the big electric bill and sunglasses for all: 3) the 250w MHs Your friend in fish, 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

Lighting Bob- I was wondering if you could explain the difference between fluorescent, power compact, VHO and metal halide lighting. I understand that, in general, hard corals need stronger lighting than soft corals but how much lighting is too much (so corals don't burn) and what is the minimal lighting needed to support a basic live rock and soft coral reef tank.  <Well, some basics: the first three are all types of fluorescents... and Metal Halides produce photons by way of a different physical principle... But I don't think this is the information you want... Your understanding re soft and hard corals is the same as mine. Most soft corals can get by on half as much PAR (photosynthetically active radiation, a measure of the strength of useful EMR wavelengths)... But let me stop, or slow here and say that what you are asking is very important, germinal to successful husbandry of light-needing life... but not easy to answer in a short period of space and time... Instead, I have more detailed articles to refer you to at www.wetwebmedia.com on the Net. Read these over (re light, fixtures... for marine aquariums). There are just too many factors to elaborate on here: Dissolved color in the water, depth of the tank, light extinction coefficients for different light sources... to give a fast formula of oh so many watts or lumens per this or that measure... I'll answer more satisfyingly with your specific circumstances listed below> Also, how does each type of lighting affect algae growth (both good algae and bad algae)? <What do you mean? How does photosynthesis work... the same mechanism for each type of light... but more for more of the photonic energy produced by any given type of lighting type... More to the point, in general are issues of whether a given light source will produce how much useful wavelengths for purposeful (desired) photosynthesis... for the most part, the same wavelengths that boost hermatypic corals et al. also boost thallophyte (algal) metabolism... The control of noisome algae is more a matter of maintenance, nutrient competition and predatory control than producing the "right" amount or types of visible light> Lastly, what is the difference between the four types of lighting in regards to how strong they are and what type of spectrum they have. <The MH is "strongest" per rated watt, but most are "less efficient" than most CFs... i.e. they CFs produce more useful illumination per money overall... due to the MH consuming more power than their rated equivalent outputs, fixture and lamp investment, replacement... with the VHO, HO and regular output fluorescents ranking very down... but being highly variable depending on lamp, ballast types employed... The spectral mix has much more to do with the type of lamp than the mechanism of light production... Do you understand concepts like Color Rendering Index, Color Temperature, Intensity and Spectral Shift...? You will soon> I currently use two 36" 30W blue and two 36" 30W white. I would like to support both hard and soft corals and will upgrade my lighting to what you suggest. FFExpress seems to have a great selection. Thanks for your help once again. Rob  >> On how big, deep a tank?  Bob Fenner

Fiber optic lighting bob  have you heard of anybody using fiber optic lighting on reef a tank ?  lightolier corp. has fiber optic lighting coming out on the market Feb./march.  the light generator is available in 175w,250w and 400w metal halide. it will be able to handle up to 10 fiber optic cables. the tips on the cable will be available in various degrees of spots and floods. I am thinking of trying this out on my tank. you can sit the light generator on the floor or inside the stand, place a 12k or 14k bulb in it and run the cables up into the hood. no heat buildup! what do you think? >> Interesting to actually get a unit, hook it up and see how much useful light (as in with a lumen meter, PAR meter) it produces... Something's like this have actually been tried "on the market"... but don't know the particulars of the mechanism of light production (don't think any have been MH)... and these were mainly decor items... not functional light producers per se. As my Mom would say if we asked if we could get ice-cream if we were good, "We'll see". Bob "pistachio" Fenner

Need a light for my 45 gallon saltwater fish tank. I have had saltwater fish for many years and I am looking into keeping corals. I need to know if you carry the correct lighting I need for the tank. Please advise. Thank you, Luis Perez >> For 45's of stock sizes, look into two compact fluorescents... one of about a 10k rating the other an actinic... and get a couple of timers... These will be your best investment for getting you the looks and spectrum/intensity for a good mix of all that's available in reef livestock. Bob Fenner

Lighting Question Hello Bob I was planning on setting up a Fish only tank until I read your very interesting book "The Conscientious Marine Aquarist" now I'm hooked and would like to try to set up a tank with fish and Invertebrate system, with live rock. My question is what type of lighting should I provide for my live rock so that I can grow coralline algae and what ever may be present on the live rock. After I become more skilled I would like to move toward keeping a reef aquarium. I will be setting up a 90gal. tank and was planning on using 4 VHO lamps when I move toward a reef aquarium. I would like to know if I should start with the 4 VHO lamps or wait until I start keeping specimens that need intense lighting. I would rather put my money toward the VHO lamps now instead of buying a strip light now with twin 40 watt bulbs and having no use for them when I upgrade. Also will this be enough lighting for some of the photosynthetic corals I might try to keep in the future. I know these lights will be over kill in the beginning but I thought it would be good for the live rock. Thanks, Ralph >> Ah, the clincher is that you will be moving into more "reef" life sooner than later... and the size/shape of your intended tank (a ninety)... You could get by on just two VHO's in the meanwhile (of full-spectrum fluorescent lighting)... but I encourage you to look into a "double" compact fluorescent for now (the fish and invert. and live rock... with coralline algae) set up... with about a 10k temperature... and add two actinic VHOs when you are stepping up to more light dependent life forms. Otherwise, the four VHOs you have in mind will work... and you can switch one or more of the "white" lamps out for actinic types (and save them for replacing the others when they're old). Bob Fenner

Dear Bob, I am starting up a new tank, but it is one weird shaped tank. Specs: 40 gallons 39 inches deep <!> diamond shaped equipment (so far): 150 watt heater aquarium systems quicksand filter Aquaclear 150 filter (only size to fit on tank) I need some help on lighting needs and species preferences... Lighting - Because the tank is only 16 inches across the top my aquarist friend suggested a MH system for the depth also. I found a good 10000k system w/dimmer (name brand+small price). But I wanted to know if it was a good choice for the species I would like: 5 (A. akindynos, Sebae, or allardi which do you suggest for best candidate?) clownfish, 1 hippo tang, some cleaner shrimp, live rock (pounds?), live sand, and an anemone (E. quadricolor). Your book was GREAT! Please help soon, Chris Anderson >> What do you was? Oh, let's see. Yes, I'd definitely go with the metal halide... Bear in mind you will want to be able to adjust its height to manipulate temperature effect... And all three Clowns you list are great.... but the akindynos is my fave... and both it and the allardi are natural symbionts with Entacmaea, but the Sebae (the real species) is not... though it/they will generally "learn" to live together. Live rock poundage is a function of density (variable feature), and desired look/effect... somewhere... about forty to seventy pounds is probably what you're looking at/for... Check out the "old Acroporid" types sold out of Tonga, Fiji, Marshalls... 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, fixt. I currently have a Coralife SHO 48 inch strip and two 55 watt 6700 k I would like to keep clams, corals and invertebrates i.e. anemones. Is this sufficient.  Do I need to add a blue actinic, the SHO light strips are expensive can I get away with adding a single or double fluorescent fixture for the actinic.  I was looking at a RedSea Phazer IV, with two AquaStar 10k's and two Coralstar Actinic Blues what are your thoughts.  Confused Regards, Lou >> I take it these are on a four foot or so long tank? Depending on depth (as long as it's not over 22", like a show model 55 gal...) the present lighting should be fine, and better with adding the actinics... even if they're normal output fluorescents. The newer lighting system proposed is nicer, but not necessary... for most collections of livestock I would have... unless you intend to push their metabolisms... and have the money, expertise to contend with the induced mal side-effects of doing so. Bob Fenner... who would just add the actinics.

I have some data in http://www.aquabotanic.com/lightcompare.htm. The tablelists just one CF, the Osram Dulux L 55w/850. Its PAR/watt efficiencyfactor is about 20% higher than equivalent (CRI ~ 80) but normal-output fluorescents. I have additional, non-published results for the Philips PL-L 55w/950, a higher CRI CF. Its PAR/watt factor is about 10% larger than other high CRI but normal output fluorescents (typically a C50 full spectrum tube). I also have non-published results for the Philips TLD/950, a very high CRI full-spectrum T8 tube, that indicate its PAR/watt efficiency to be about 20% higher than normal full-spectrum fluorescents. Based on these very few but hard data points, I would say CFs and T8s are somewhat more efficient than normal output fluorescents.  <Oh yes! RMF>

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

Lighting for invertebrates Hi bob, I have a 105G tank with a depth of 29", (1) actinic 48" 10K bulb, (1) daylight 48" 10K bulb, and Tangs and Angelfishes. I'm thinking about having some anemones and certain types of invertebrates.  Please let me know which invertebrates can tolerate this light conditions and the existing fishes.  Also, what do I use to increase the light condition with low heat dissipation because the tank is in a cabinet ? Thanks, jt >> Hmmm, lots of things to say... and not much time/space to do so. For one, I would look into adding more light: either a compact fluorescent or two, or a Metal halide... but the latter does present heat problems... and the next consideration I'd throw in is to build up your live and base rock structure to support whatever photosynthetic life you settle on to place it nearer the limited (currently) light. And then I'd encourage you to start with the easier "corals" (stinging celled animals) like Zoanthids/polyps, Corallimorphs/mushrooms, soft corals like the leathers... and leave off with anemones et al. till you get some more experience "under your belt". Bob Fenner

bob....we have had our tank about 2 1/2 months with fish. I studied for about a month before setting it up. more, many articles from FAMA and a bunch from the internet. just read your comment on VHO lighting. we went from 1 actinic and 1-white (40w) to 2-40w actinics and 2-110w VHO. anemones love it but no one said we were going to be cleaning the green algae from the glass daily and the gravel weekly. actinics stay on 12 hours and VHO's are on for 6 hours. how do I provide the needed light for the wildlife without the algae? we have four turbo grazers and 5 Astreas but they are fighting a losing battle.  thanks, Jim nix >> Ah yes, the eternal struggle: providing enough light energy for photosynthetic reef life, without over-growing undesirable algae.... Well, there are a few ways to go: the easiest/best? Grow some algae you do want! With live rock and/or macro-algae that you're attracted to... compete for light and nutrients in the place of the "green".  You could even rig up a separate sump and grow this stuff there. Next, do consider "raising the bar" on your algae eater front. A fish or two like a lawnmower blenny, Ctenochaetus or Zebrasoma Tang (see an assortment on articles of the same names on my wetwebmedia.com site if you'd like).  Lastly, there's the possibility of enhancing the removal of chemical foods that are boosting your problem algaes proliferation: Beef up your skimming, use activated carbon or other chemical filtrants... Best of all, adapt/adopt all three of these strategies. 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

Mr. Fenner, I've been reading tons of articles on the proper lighting for a reef tank and have found that there seems to be no clear "best" choice. Metal Halides work, but they're very expensive, have widely (and difficult to determine) levels of quality / suitability, etc. Normal fluorescents can work, but you'll probably need a lot of them to provide enough intensity. VHO lights can work as well, but certain regions of their spectra fade quickly with time. Compact fluorescents have been called by some "the best possible solution," since they're efficient, are small (many can be used), can provide the correct spectrum, and don't lose their spectrum quickly with time (I don't know how much these cost). The general principles seem to be: 1) You must have sufficient wattage 2) You must provide this sufficient wattage in the photosynthetic region (about 400 to 700 nm wavelength) My additional requirements are: 3) the cost of the lighting can not break the bank (no more than about 200 bucks) 4) I don't have to run out and buy bulbs every 4 or 5 months 5) the lights don't get so hot (7" from water) that they cook my tank inhabitants Now, I currently have a 55gal fish only tank, which happens to contain a maroon clown. I would like to add a bubble anemone for the clown and maybe a few hardy corals..... I'm planning to buy the necessary equipment to install four 48", 40watt 50/50 (actinic white) bulbs. Will this be enough for a bubble anemone and a few hardy corals?? If not, what's the minimum setup I need. If my setup is sufficient, is there anything better, but only slightly more expensive? Thank you. Cordially, ENS William James Yavelak >> What a joy to receive such a well-thought out and well-researched query. Do agree with much of your assessment and observations. For function's sake (versus simply looks) there are a few ways "to go" in lighting a marine system... and a range of incidental costs. Metal halides are great, given the depth of system, some way of disposing of the waste heat they produce, and their initial high, operating and maintenance costs...  The number of watts is not as useful a measure of supply per gallon as is PAR (photosynthetically available radiation), and there are (I don't want to hear anyone groaning) actual PAR meters...  The four lamp scheme you mention should be fine for your 55, but I would still consider the compact fluorescents for the non-actinic light... Bob Fenner

I have a 125g tank that I set up a little over 3 months ago. I've got a few damsels and I just added 45lbs of live rock. My tank came with 2-36" light fixtures and I've got 1-20K Actinic and 1-Blue in the fixtures. I'd like to add additional lighting but I'm totally lost on this subject. I will eventually be adding more fish along with a few corals.  Lighting seems really expensive but my current lighting leaves portions of the tank somewhat dim. Do you recommend DIY or buying fixtures ready to go? Are all lighting systems expensive ($300 - $600). Can you recommend the most affordable way I can upgrade my lighting. Thanks >> Gosh, good question... Well as you know and will concede, this field changes very quick (lighting of aquariums)... but I would definitely look into adding a compact fluorescent "regular" full spectrum of about 5,500-6,500 Kelvin temp. rating to your existing set-up (125gal. with the lights you have)... as the very best (current) choice. And I would look into the DIY possibilities as well as the store bought fixtures, from just buying components and putting them in yourself standpoint... There are big "home chain stores", and a few pet-fish frontiers of this gear... Bob Fenner

Aquarium lighting Dear Bob, Enjoy your stuff. Have a question. We have a 150 gallon tank. Dimensions are 8' long x 21" tall x 19" wide. Filtration system is wet/dry. Substrate is 1-1 1/2 crushed coral; with other natural (not live) coral pieces. Also have two - "Aquarium Systems, MJ-1000 Maxi-Jet" circulation pumps inside the tank. The lighting is 2-black lights; with 2-full spectrum aquarium fluorescents; all of which set approximately 18 inches (full-length) above the tank. Water tests are good. Our current species are wrasses, damsels, clowns, gobies, 1 fox-face, etc. Just a couple of each; not over-loaded. No problems with algae; fish doing well. Tank set-up was February, 1999. We are currently October, 1999. Need to know if we should upgrade the tank flow (by adding more maxi-jets) and lighting. Eventually, we would like to do "reef". What do we need to upgrade? Thank you, The Moons >> Thanks for writing. Yes, I would increase both the lighting (by about twice) and circulation. Do you have a protein skimmer? You'll need one of these as well. You might want to look into compact fluorescents to replace the full spectrum fluorescents, and use the "old" fixtures for more "black lights" (actinic lighting). And maybe consider a sump (outside tank) that you can use as a filter et al. container and the pump for returning the system water as part of your added circulation. All of this ahead of "going reef". Bob Fenner

Metal halide 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

Hi Bob. From my research I've noticed that a majority of corals (at least those I've looked at) prefer medium to strong lighting. I've come to terms that my 125 gallon tank has a low amount of light (180 total watts) for these corals but I've also discovered (well, found them in a book =) several corals that do not need require, or even like, a high amount of light. Could you recommend some of the less obvious (like Tubastrea) that I may have missed that should do well with my light arrangement? >> Yikes, just the type of query I like (involved and thoughtful), but can't hope to answer in a short response... Well, first off I commend your personal search/research re your potential livestock's' living requirements... and the look/investigate before you buy approach. And I do concur with your observation. Of course, relative to what we are accustomed to farther away from the equator, it's very bright in the tropics, even under shallow water. And yes, there are many non-photosynthetic stinging-celled animals (even in the true coral Order, Scleractinia), some are even reef builders though being ahermatypic... Now, about simply listing the families, genera, species that have no, lower, least light intensity requirements... I'd rather refer you to Veron's or Nilsen and Fossa's books... not simply to save me time (there are MANY, though not that many that are currently commonly found in the resale trade), but to not "paint" a too-simple picture (you can imagine the damage you and I could do with such a posting being read by new reef keepers... "let's see, this is probably an easy species to keep, because that knuckle-head Bob Fenner said it doesn't need much light..."). To repeat, there are many true/stony corals (and many other stinging-celled animals that are lazily labeled as "corals") that don't need much in the way of light. There are references that detail this, among other essential husbandry notes... I'd study these. Bob Fenner MH nec. for Scler.? I would like to first thank you for the past information you have passed on to me. I am going back and forth with the lighting issue. The two retailers that I do business with both use MH for light on their livestock. They both have told me that if you plan to keep stony corals (Acropora sp.) I should us the MH. At the present time I have no interest in keeping this type of coral, but if my tastes change will VHO or power compact be enough light? In your opinion which is better VHO or Power compact in relation to performance, and operating cost? How many watts should I use on a 36 X 24 X18 tank or 58 gal? And what name brand would you recommend. I know that you don't recommend MH for reef keepers, but if there is one plus that would pull me towards MH what would it be and is it worth it in cost and performance. Thank you, AJB >> I appreciate your support and your query. Hmmm, let's see. It wasn't till too long ago (a year or two) that MH was not only the best, but close to the only practical way to get intensity and quality of light for all eventualities. Additionally, as you might surmise, for the retail, the appearance of livestock is extremely important: MH lighting (often with actinic fluorescents) show off the organisms on offer like nothing else.     To answer your second paragraph, Power Compacts beat VHOs in set-up, operation and replacement costs (per PAR, lumens, even appearance). Ah, Brand Names... I rarely "do" endorsements for a few reasons. I'm good friends with many people in the business side of our aquaristic interests... the players and their products change much more frequently than posted, printed information... and in this case, there are many makes/models that are so close, that there really is little difference. I would take a stroll through the hobby magazine, Freshwater and Marine Aquarium (I'm sure you're familiar with this publication, but for browsers I'll mention they do have a website).     And I do suggest MH lighting for deeper, larger systems. Here, these fixtures reign supreme. Not only is MH illumination gorgeous, it "punches" to depths with strength ahead of all other types of lighting. In my opinion if you either have a tank that is two feet deep (or more) or can make sense of the added electrical cost, waste heat, potential burn and even explosion potential versus the beauty and photosynthesis driving ability of MH's, go for them. For larger systems, I'd actually incorporate both MH and CF's... Bob Fenner

Question: Hi Bob, I had just purchased a 75 gallon aquarium and 1- 45 lb box (FFE Special) of live rock. In this tank I had put about 2 1/2 to 3 1/2" of 'Seaflor' Aruba style which is one of the chunkier types of substrate. I am not wanting a total reef set up, as I love to watch fish rather than polyps. I have a protein skimmer and a CPR900 wet/dry filter and a 48" 40 watt 50/50 bulb. My questions for you are: is the substrate I am using too "chunky" and how much more light ( without using VHO or MH) do I need for the LR and its' inhabitants. Also, any suggestion on what would be the best fish for this aquarium? I do like tangs and triggers, but not sure if they are compatible. I do however, have a Raccoon butterfly that won't eat anything except what little algae is on LR in my 30 gal., would he be good for the tank?

Bob's Answer: Robyn, I would add another four footer or two of the 40W fluorescents, if you can afford it up-front, with electronic ballasts. At this point, unless you really are probably going the big reef scene, I'd stick with the less than VHO route as your live rock will accommodate to the amount of luminosity the 2, 3, 4 other output fluorescents will provide. There are tangs, triggers and that raccoon B/F that will get along, and do place that last in the new tank and provide some sort of meaty food (Raccoons are toward the nighttime zooplankton feeders in the wild).

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.

Question: There is a brown crud in my 55 tank that turns to slime when I take it out of the water. It looks hairy, but seems to not have any rigidity or form. Sort of like string, but less than 1/8 inch long. Sort of fuzzy. Someone told me this was a dinoflagellate plague. The water quality parameters are fine. We recently installed new VHO bulbs, which caused the tank light shock, but then tried just using half the bulbs for a while. I think that had something to do with the bloom. Maybe accidentally killed off the good algae and the bad stuff moved in. I just put a phosphate bag, Kent carbon, and nitrate remover bag in the trickle filter. Should I go back to using full lights? I figured that maybe by turning the lights off for 24 hrs that we could starve it if its photosynthetic. Also I did a 50 % water change. I have 150 lbs-200 lbs of live rock with a live sand bed. The tank has been set up for 2 years. I plan on adding calcium hydroxide by IV drip tomorrow to raise the ph (now is 8.1) Any ideas on how to get RID of this brown slimy stuff? I do not want to use antibiotics unless it is a last resort.

Bob's Answer: I agree with your diagnosis re: the apparent cause - it probably was the light changes (good to change slowly, like one bulb at a time over a period of weeks). By the description, it is not dinoflagellate. Probably some other mix of algal, and aufwuchs and will be soon out competed by bringing more of your lighting into play. So start phasing in same and leave off adding or changing anything else for a good month or so until you start to see the system "return to center".

Question: I am in the process of setting up a new tank and have a lighting question for you. I will have a fairly deep tank in my opinion at ~30-32" depending on water level and want some help to understand what it will take to light it. Is there a standard method for determining how much light a tank should have? In my case a fish with some live rock tank. For example maintaining a certain watt/gal. ratio. Or is it simply the more the better. Also, how does the depth of the tank come into play? Any help you could be on this would be enlightening!

Bob's Answer: Hey Michael, hardy har har. Yes there are some useful "rules of thumb" re: lighting matters and depth. First off, the usual declarations re: the range of photo-adaptability by species and individuals of types of marine life. To some, being in the light or not matters little. To those that it does, there exists a HUGE range of suitable (maybe read that tolerable) light intensities, qualities (like CRI, PAR, temp. rating) and duration.... Beyond these considerations, dissolved color in the water makes a BIG diff. as well (chemical filtration, adequate skimming, etc all help here)... but all that being written (and ahem, getting down to brass tax), historically (here it comes), coming to grips with light extinction coefficients (Maxwell-B pls forgive me), absorption, diffusion and reflection of light (no wonder underwater photography is so tough), you're down to a few practical choices in mechanisms of light production for your (and greater) depths. For photosynthetic org.s requiring or your desire to boost/accommodate the metabolisms of same, metal halide (MH) or power compact (PC) fluorescent lighting. Both these will give you useful amounts and kinds of light at three feet... otherwise you should study up and select life forms that don't have specific light requirements... there are many soft corals, Zoanthids, Corallimorpharians and much much, mucho more that fit into this category...

Question: I have a question for you. I am going to be updating my lighting on my reef tank, and I was curious to know what your opinion would be if I bought a metal halide pendant for my 55 gallon aquarium. I was looking at a 175 watt pendant with an electronic ballast for dimming to simulate dawn and dusk. If you could give me your opinion on this situation, I would greatly appreciate it.

Bob's Answer: Hey Tony, thanks for writing. Actually, for the shape (most 55's are 48 X 13 X 20,22 inches), volume of your system and whatever you desire to keep in the way of livestock and induce it to do (let's say at the zenith, pushing SPS like the family Acroporidae for maximized growth and fragmentation), I'd strongly urge you to consider compact fluorescents number one and some type of VHO fluorescents secondly. Both can be dimmed, will produce useful lighting quantities/qualities (and much more evenly than a single pendant over a four foot reach), produce much less waste heat (do you really want to buy and run a chiller?), and cost less to procure and operate than the MH. Take a long look around (particularly through the Reef listservs that you can find through your Internet search engines) on the issues of alternate lighting sources for captive marine systems, and do it yourself vs. store bought fixturing. There's a lot to investigate, but isn' t that one of the things that makes this hobby so much fun?

Question: Hi, Bob, I currently have an 85 gallon hexagon aquarium. I am purchasing a 10,000K fluorescent bulb, and also an actinic 03. these bulbs are both 24 inches long, roughly the width of the tank. It is a tall tank, and I was wondering if this is enough lighting. Do you think this will be sufficient lighting for my live rock to thrive, and also grow a bunch of coralline algae? I am putting Kent Tech-CB in the water to maintain calcium and alkalinity levels for good coralline algae growth. I also was wondering what your suggestions for fish would be. I want a community with some Chromis, clowns and a tang or two. What would be two tangs that I could have together without much fighting between the two.

Bob's Answer: You can always add some more light to the top or sides later, but this should be enough to start. A Zebrasoma and Ctenochaetus tang species of your choice should do fine...

Question: I am fairly new to the hobby and am interested in setting up my aquarium in small steps. We currently have some damsels, snails and blue legged crabs. If I add live rock now will it kill all of the current occupants? Also can I add small amounts of live rock until I arrive at the desired amount? Lastly, If I do not currently want to support inverts that would call the live rock home do I need the suggested amount of light now or can I add the high intensity lights when I decide that it is time to add the inverts? Thanks a lot and I really appreciate your column.

Bob's Answer: Don, you can add very small amounts of CURED LR a little at a time, but it is far better to make sure and cure it yourself and introduce it all at once. Do you have another tank or safe container to effect the cure? Or to move your current livestock to while you're curing the rock in their tank? Good query re: the light. Some decent intensity and quality of light is necessary. You don't state the size or shape of your system, but need to investigate thoroughly what your options are... in the short term (initial cost) and long term (electrical, lamp replacement)... Look into compact fluorescents first.

Question: I am in the process of converting my 55 gal tank into a reef tank and I have a few questions. First of all how many watts of light do I need? I know the rule of thumb is three per gallon but I want to keep some hard corals and would like the opinion of a pro! Second, I have around 90 Pounds of rock (some Fiji some Florida) and right now I'm just running a Skilter 250 and a Berlin Skimmer no carbon on the Skilter, just once a month), I'm thinking of converting to a sump and some have suggested a Fluval!?! I'm a little confused but determined. Your advice, please.

Bob's Answer: Hi Chris, don't get me wrong, but you are on the brink of great personal revelation! Don't get bogged down on watts per gallon notions. You do want enough PAR for your buck as you (and your livestock) can stand... so instead I'll encourage you to investigate compact fluorescent and boosted (high and very high) output fluorescents (for the typical 55 gal. 4 foot long, twenty two inches deep the MH crowd is easily aced out in terms of initial and ongoing costs...). Re: needed/ancillary filtration/circulation, I'd set-up the sump and power it whichever way... my preference is for an Eheim way over Fluval or anything else for water movement

Question: I am presently having a house built and will be moving at the end of March. I have a reef tank which has been set up for 3 years now and is well established and stable. The new house will have a perfect spot for display, however, direct sunlight will be a factor from around 2:00pm until dark. I have been advised that this is not the way to go due to the fact that this will cause an algae bloom. I thought that this might encourage reef growth with less artificial lighting. The sunlight can be suppressed with a blind. What do you think of my situation and what would be your best advice for me?

Bob's Answer: Don, I wouldn't be set off by the incidental sunlight one bit. If indeed the intensity and wavelengths of natural light become a problem you can shade it later. BTW, many public aquariums and culture facilities utilize as much natural light as possible.

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