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FAQs about Metal Halide & Halogen Lamps for Marine Systems 1

Related FAQs: Metal Halide Lamps 2, Metal Halides 1, Metal Halides 2, Metal Halides 3, Metal Halides 4, Metal Halides 5, Metal Halides 6, Metal Halides 7, Metal Halides for Small Systems, Metal Halides for 40-200 gal. Systems, MH for 200 gal. Plus Systems, Metal Halide Fixture Issues, Metal Halide Heat Issues, MH Repair Issues, Compact Fluorescents, Regular Fluorescents, Lighting Marine Invertebrates, LR LightingTridacnid LightingSmall System Lighting,

Related Articles: Metal Halide Light, & Lighting Articles, Coral System Lighting,

Wanting to downgrade lighting Hi Bob, << Blundell today. >> I have a 36"L x 18"W x 30"H tank with 5" DSB. Planning to change my 2 x 250W SE MH lights to something else due to the high electricity consumption and heat contributed by the Metal halides. Would like to find out what other alternatives do I have in order to meet the minimum requirements of a 30" depth with mostly SPS at the top and LPS at the bottom / middle portion of the tank. << I wouldn't down grade your lights.  Pricey as it may be, that sounds like good lighting.  If anything I'd switch to 150 watt double ended but I'd still rather have your two 250 watt. >> p/s: I have attached a photo of my tank, hope it helps. Thanks for your precious time, James
<<  Blundell  >>

Ideal halide Kelvin rating? Hi bob, << Blundell here. >> I'm using 2 x 250W 20K BLV now, I love the soothing lightings & colours of the corals shown under it but I notice the PAR might not be strong enough to reach the corals at the tank bottom and also the Acros are not growing as fast. << Yes I have that exact type of lighting and problem.  I really like the 20k look but the amount of visual light given off is just way too low. >> Have tried the 10K before, love the growth and PAR but dislike the bright whiteness of the light and also the corals ain't that colourful when compare with the 20K bulbs. Pls give me your advice. << You asked the right person.  I've been looking into this heavily and have decided (for the time being) that the Aqualine Busch bulbs are probably the best.  But the brand name is only somewhat important, the main key (to looks and growth) I think is probably the new line of 14k's now on the market.  That is what I'm switching to.  However, 10k's with supplemental actinics is really nice as well. >> regards, James <<  Blundell  >>

Kelvin? hi I was wondering how much Metal halide lighting to have on a reef aquarium in Kelvin ???? thanks >>>Hello, There is no answer to your question as stated. Kelvin is not a measure of HOW MUCH, but of color temperature. 10K and 20K are the more common choices when speaking of such. The higher the rating, the more blue the light is. I've recently become a fan of the 20k HQIs after running the 10k's for years. Jim<<<

Light Temp - again. hi I was wondering what is the best Kelvin to run on a reef aquarium??? Without any fluorescent etc. thanks >>>Hello Dana,    There is no conclusive data pointing to a "best" Kelvin range for a reef tank. Besides, there are deep water critters and shallow water critters which are certainly accustomed to various Kelvin ranges. For the purposes of most reef tanks, anything between 10 and 20K is fine. Jim<<<

MH Q's Hello there crew,          Thank you guys for all the valuable info you've given me! <No problem :D>    Once again I'm stumped and need your guys help.  I'm looking to buy a MH lighting system for my 70g tall tank (36x18x24) with a 5-6" sand bed.  I'm looking to keep clams and SPS corals along with a Heteractis Magnifica (beautiful but demanding I know).   <Very demanding, and best kept on its own in a species tank.  These anemones can get to be a meter across, and will feel a bit cramped in your 18" wide tank!>   I've more or less decided on dual 250w 10k Ushios <I'd go with 400W for this anemone if you decide to get it-- it needs a LOT of light.  If you stick with just SPS/Clams 250 should be okay.> but can't discern what is the big difference between the regular socket type bulbs and double ended HQI bulbs.   <In general HQIs put out more light per wattage>   Either way both will run off the appropriate dual PFO ballast.  Both of  them will have reflectors and a glass cover also.  My big question is are either of them more powerful than the other?  I've read that HQI's can have higher PAR values than regular bulbs.  I've also heard they have a bluer output than traditional bulbs of the same wattage and cooler temp.  They also require a digital ballast from what I've come to understand also.  That explains the higher cost of the HQI ballast I suppose.  I like the 10k color spectrum when used alone and just need to know some of the Pros and Cons of the two formats (HQI vs. Standard). <Well for SPS corals just about any of the commonly sold bulbs will grow them just fine.  If you're looking to farm them or something I'd go with a combo of 10000K and 20000K OR 6500K and 20000K.  This is what Steve Tyree has suggested in the past.  But it really comes down to your color preference when choosing what Kelvin you get...>                            Sincerely,   Chris  AKA  ~ fishtank ~ 20K is Ok! Good morning. <Hey there! Scott F. with you today!> My question for today: I am thinking about ordering retrofit kit with MH  2- 250 watt 20000k bulbs. I was told that I could only leave the lights on for 6 hours a day and not 12 hours because of a potential algae bloom. Is this true? The tank is 120 gallon. Thank you. Cecilia <Well, Cecilia- the light spectrum really is not the cause of nuisance algae. It's more of a function of nutrients which favor algae growth, in combination with high light intensity. For example, there are numerous hobbyists working in the field of coral propagation, and they are often growing corals out in greenhouses, with abundant sunlight. With proper husbandry techniques, you never hear of algae problems in these systems. I think that you'll be happy with the results of the 20000k bulbs, when used with animals that utilize this spectrum, and with common-sense nutrient export mechanisms. And the photoperiod? Use what works for the animals you keep! Good luck! Regards, Scott F>

New Book and MH Lighting - 7/7/03 I received the new book the other day and may I say what a wonderful book it is!!! I have learned a lot from it and I have only scoured the first few chapters!!! Can't wait for the next in the series!!! <Thanks for the inspiration <G>!> I currently have an AGA 65 gallon, and have changed (this past weekend) to metal halide lighting. I have a PFO 175w ballast running a AB 10K bulb. I'm not real pleased with the color (kinda yellow) and it's not real bright. Any suggestions? I was thinking about switching bulbs to the Ushio or Blueline 10k bulb. I'm looking for a bright, crisp white color. <The Ushio is a great bulb IMO... but the Blueline I would not personally take for free. Your AB is also a fine quality, if not color, for cnidarians> Again, great book!!!! Thanks, Jim <Much appreciation my friend. Best regards, Anthony>

The "XDE Factor" Hello there. <Hi there! Scott F. with you today!> I was wondering if you Guys got any good dirt on the [XDE 250W 20,000K double ended] HQI form Hellolights. Is it good light? Will the bulb last and burn ok, will it work ok with Hamilton HQI ballast ? Any charts on this light? I can find any. <I don't know about the bulb's compatibility with the Hamilton ballast. You may want to talk to the helpful folks at hellolights.com on that one. I can say that I have seen the bulb in action, and have heard positive feedback from users. It looks to be a bit less "blue" to me than the Radium or Ushio 20,000k's. My friends who have tried them like them and claim good results, although I have not seen any tests or PAR information on them (I'm sure Sanjay Joshi will get around to it soon, though!).   Trying to bring the colors back in my tank the one 250watt MH 10,000k Hamilton bulb is to white and yellowish to me. <I agree with you about the appearance of most 10000k's. I use Aqualine 10000ks right now, and find them to be too "yellow" for my aesthetic preferences...I like Blue!> I liked the VHOs looks two white two blues on my 180 reef. <Yep- a more "balanced" look, IMO Trying to find someone that has used this light and what they thought of it. Thanks for your time. <Do ask around on the WWM Forum, and see if any of your fellow hobbyists have had experience with the bulbs, or can send you som pics...Good luck- and send pics of your tank should you go the XDE route! Regards, Scott F.> Chris

MH lamp orientation 7/19/03 I have a question for you guys, <our pleasure and purpose here...> I have a 75 gallon reef aquarium set up, it have been set up quite some time but I have only managed just to keep a few corals in the tank (haven't been aggressive about adding more stuff). I have recently gotten a reef bug and I am prepared to keep a full tank of corals. My current set up includes 2 175watt 10k metal halide and 2 96watt pc 50/50 bulbs. I currently have a Knop calcium reactor ( for future SPS corals ) and have a ETSS reef devil skimmer( just love those downdrafts skimmers !!!) my question is will this be enough light to keep a variation of corals and clams <yes... easily> and recently acquired Long tentacle anemone <oh, no! please do not mix motile anemones with sessile corals... it is a recipe for disaster in the long run for so many reason. Keep it in a separate dedicated tank. At the very least... isolate it in a refugium to serve as a biotope display> and also just reading some other reviews I am hearing bad things about pendant MH's, which is currently what I have.. and seems to be related to the bulb hanging vertical. is that true... I just need your opinion on my set up thanks. <correct... vertical pendants focus light and do not disperse it as efficiently as horizontal orientation. Best horizontal and perpendicular to the long sides... and with a parabolic reflector for best results. Kindly, Anthony>

MH lamp orientation/color II 7/19/03 ...and also for my set up.. its time for me to replace my MH bulbs I was thinking of having 6500k instead of the 10k... do to the fact that my LFS is telling me that clam and SPS corals grow best under those lamps instead of the 10k and also would the 96x2 50/50 power compacts balance that light as it has more yellow content in it. <I would agree that 6500K lamps are very good for zooxanthellate reef creatures. Many good lamps out there. Iwasakis 6500K are very fine. Anthony>

MH lamp orientation III 7/19/03 thanks for your prompt response, I will certainly digest that information... one more question... just to be sure I understand, there is really nothing bad about having the pendants, just that they do not disperse light as wide... <essentially true... pendants are best for tall narrow tanks> so for my set up which is 48"x18"x20" is true that a pendant is good for about 2' of tank length and depth and if that is the case then my set up is just fine or is it something that needs to be corrected? <it is not so much "good", per se, for 4 foot long tank but instead has a rather narrow and focused beam of light to deliver. 3 vertical pendants are needed on a 4 foot tank that would otherwise require only 2 horizontal lamps. Anthony> MH lamps 7/9/03 Anthony,   You won't remember me, but to refresh your memory, I have a 75g reef tank with (as you recommended) dual 175w MHs.  Everything looks great, but now I'm wondering about the bulbs I have.  As expected, the canopy came with Venture 5,500k bulbs, and they're quite white, and fairly generic.  Now, here's the thing: because the canopy is so large, I have no room for actinics.  Is this going to pose a health problem for my coral? <good heavens no... most all MH lamps out there have more blue than corals need in them. The lamps over 10K are somewhat of a waste in that regard> Also, what bulb upgrade would you recommend for coral growth/health?  I have been looking at the 10,000k Aqualine, 10,000k Ushio, and 20,000k XM bulb from hellolights.com.   <I have experience and respect for the first two listed> To be honest, I'm hearing great things about the XM bulb.  What are your thoughts?   <don't believe everything you hear ;) Or rather... ABs and Ushios are time tested and reliable. Getting my vote in preference> Thanks a lot--I'm really hung up on this whole bulb dilemma. Sam Minneapolis, MN <best regards, my friend. Anthony>

-250w floodlights suitable?- Hi there fellas, I am planning to upgrade to MH on one of my tanks.  In my research, I have run across some 250w MH 'floodlights' that look very similar to the rectangular pendants sold for reef use.  My question is, can I put a 'reef bulb' in this light fixture and save some money? <If it's the correct ballast with a mogul socket you're good for go! Although it seems kind of straight forward, you may want to try firing someone's old 250w MH lamp first, just in case. -Kevin> Thanks a bunch, Aquaholic

Shedding A Little Light On Bulb Choices Hi Crew, <Hi there! Scott F. at your service!> I'm going to be setting up a 150 gallon reef tank in the next few months and am sure to have a few more questions for you between now and then but, for now, I'm wondering what wattage of Metal Halides to use?  My tank dimensions are going to be 48"x24"x30", 30" being the depth and was figuring on using two bulbs equally spaced across the top.  I plan to make this an SPS tank emulating a shallow reef environment and plan to stock accordingly.  Much research left to do on coral species relating to said niche but have found your site to be an invaluable resource.  Keep up the great work!  Also, what would be a good color temp to use here? Regards, Ron <Well, Ron, in a tank of this depth, I'd use nothing less than a pair of 250 watters...I like DE bulbs, but the choice is yours. I am a big fan and recent convert to Aqualine 10000k's, supplemented with some actinic (for aesthetics) if you want some blue. The colors of your corals will be awesome! I used to use exclusively 20000k's, but coral growth didn't seem as significant. My SPS nerd friends would want to frag vital bits off of my favorite body parts if I don't at least mention that you could consider two 400 watters as well. I think that is overkill, myself, but some people feel that you just can't get enough light for SPS...Hope this helps! Regards, Scott F>

Metal Halide lighting 9/2/03 Thanks for the response.  One more question.  The DE bulbs in 150 and 250 watts. My impression is that they give off more PAR and thus are brighter than the mogul type bulbs.  Is this true and would a 150 DE be comparable to 175 mogul? Thanks, Sam <the point may be altogether moot. Aquarists often get caught up in buying their light systems without considering/knowing their exact species list. Even worse if they want a garden reef mix (unnatural hodgepodge of SPS, LPS, clams, soft corals, etc). It assumes that all such corals have standardized needs for light despite coming from wildly different depths and turbidities. My advice is to make a list of corals first... focus on a niche (shallow water, daylight color like Iwasaki)... deep water as with LPS/corallimorphs (cooler lamp with still high PAR like Radiums)... or run down the middle with Ushio/Aqualines at 10K. Best of luck, Anthony>

Last HQI questions before ordering 10/21/03 I really appreciate you spoon feeding me about lighting but after frying my coral collection with too much light a few years ago, I am scared to death to upgrade my lights.  I've read through all the lighting articles and FAQ's, I have done many google searches for more lighting info, and have visited other online sources and lighting companies.  These are the last few questions I have been unable to find answers for. I've found that an IceCap VHO retro kit with fans is going to be about the same amount of $ as a HQI 150W system.  I am leaning towards a PFO HQI ballast and 10K Ushio double ended bulb from Champion Lighting with a Reef Optix III pendent from Specialty Lights.com (I hope this is not stepping on toes, but I've never ordered from specialtylights.com, do you know if anyone has ever had problems w/them?)   <do keyword search the big message boards for a broad consensus on customer opinion here> Corals grow well under 10K HQIs, but how is their color to the human eye under 10K HQIs?   <very attractive to most people... it is perhaps the most popular lamp color at present> Will they need supplemental actinics to balance out the "look" for the viewer or are HQIs fine as the only light?   <nope> Are the 20K's too blue or are they better for deeper water corals? <both... seriously> Will HQIs over a 50 g 18"H with 2-3" sandbed be too much light for Pectiniid corals? <hard to say... depends on where the specimen was collected. Likely not though> Thank you for all the help you've given me on lighting, this has been a scary thing for me to do what with the bad experience in the past and the output of so much money for a new system.  I am afraid that I will put all this money into something that will only cause more prob.s or after the purchase is done, I'll find out that I should have done it another way.  Your input and experience has not only tempered many of my fears but I never really considered HQIs before Anthony recommended them, thanks so much for "holding my hand". Sincerely, Chris     <wishing you the very best. No worries, the 10K HQIs are excellent all-purpose reef lights. Anthony>

Metal Halide lighting a 60 gallon - 12/7/03 Hi I have some minor lightning problems which I hope you can help me with. <See what I can do> I plan to upgrade to a 50-60 gal, 16-18'' high tank, in which I plan to have mainly soft corals like Sinularia, Sarcophyton, buttons and mushrooms. I plan to cover the tank with a glass cover. My choice is between buying a used 150W single ended MH, in witch only a 6500 K bulb fits or a double ended 70W MH, to which I can get a 10000-14000 K bulb. <are you sure that the 70W is for aquarium use?> The 70W is not originally for aquarium purposes, <Ahhhh> but have been used for show off lightning at a car market. <I guess these are OK but where are the bulbs coming from here?> I have the opportunity to supplement with 2x18W fluorescent. <Not necessary, but could be used for aesthetic reasons if you must> The shape of the tank makes it difficult to have more than 18W fluorescents. Will: (1) 150W 6500K + 2x18W actinic (2) 70W 13000K + 2x18W daylight/10000K/actinic <So are you saying that you are going to use the combination above?? or is it a choice one over the other. The combination above would be pretty good. Why can't you just get 2 250W pendants? Something to that affect?> or both alternatives do the job? <More than adequate for your intentions to keep soft corals for sure> If I choose the 150W MH, will it be possible to have other types of photosynthetic animals (LPS, T squamosa etc)? <Possible, but the Squamosa might be pushing it. Check with Barry at ClamsDirect and see if his Squamosas would be capable of handling your depth and lighting scheme. www.clamsdirect.com I would go for maximum lighting ( 2x 250 or 2x400 if you can afford the cost and electricity) and keep any type of coral and any other light dependant inverts you want! At least that is what I would do if I were Brian Boitano! (random South Park reference) Sorry. ~Paul> Thank you  /Anders

MH wattage and color temperature question Hi, Thanks for the quick answer. <our duty> I meant a choice one over the other, (1) or (2), not the combination. <Oh. Then I would go with the 150W> Did you mean that a 150W 6500K without any additional actinic would be OK for the soft corals? <Yep. We don't use them at the aquarium and I don't use them at home. We have well documented growth without the supplementation of base actinic use with both soft, LPS and SPS. We use a mixture of bulbs 6500 and 10000> You can buy 70W HQI aquarium lamps/bulbs in Europe, I don't know if that's common in the US.  <HQIs are available here in the US but I have little experience with 70W.> If I could afford it I would buy new ones, <Not necessarily new ones but just higher lighting options.> but if I were, there would be just cents left of my aquarium budget. <Understood ~Paul> /Anders

- Halogen Lighting? - Thank you again for your time!! First one:  Today in a fish store I saw a halogen light set for sale.  On the box it showed these lights over a fish tank, and in part of the description the company said.  Fits in wonderfully with metal halide lighting as a cheaper alternative.  These 500 watt halogen lights can be used in conjunction with actinic 03 blue metal halides, or any halide bulb, to create a beautiful well lit aquarium.  Is this true? <It will light the aquarium well, but it's not a good substitute as far as lighting spectrum goes. Would be fine for a fish-only system, but worthless for photosynthetic animals.> Can I go to Wal-Mart and by 500 watt Halogens and use these? <You can... but I wouldn't.> Sounds to good to be true to me. <It is.> And finally what do I feed brine shrimp if when they hatch there are to many to put in my display tank to keep them alive for future use? <That won't work. Brine shrimp need higher salinity water than what is in your display. Would create a toxic, stinky mess.> Thanks again Craig B. P.S. I still would like to help you guys, I want to make a donation to help keep this site up and running, but I have never been given an address or what to have the cashiers check made out to. <There should be an Amazon link on most pages that allows for a donation to our cause. Cheers, J -- >

MH selection - 01/15/04 I was wondering if you could help me choose a lamp for my MH pendent. <Well, we'll see>I was thinking towards an 250w XM 20,000k because they're cheaper,<Not familiar with XM as far as quality and reliability> but the Coralife 250w 20,000k has been more popular and recommended by everyone I've talked to, <I haven't heard a great deal of positive remarks regarding the Coralife MH fixtures or bulbs for that matter. Maybe Custom SeaLife is a bit better from a price point? I personally use the PFO 250 Pendant/HQI ballast with an Ushio 10K double ended bulb. A reliable, functional, and quality bulb in my opinion but a little on the pricey side though.> and they're much more expensive. which one would you use on your tank? <I like Ushio, Aqualine-Buschke, Radiums for sure.> also, is there any real truth that moonlights help in coral spawning? <Well, a lot more goes into the cues of sexual reproduction than lighting alone. It is a reproductive indicator, but foods, water parameters and temp can be said to have an impact on reproduction as well. Nice to have moonlights as a luxury but I would not pay for it for spawning capabilities alone. ~Paul> thanks, Zach.

Double-Ended Metal Halide Bulbs? Hi Bob and Gang, <Scott F. your gang member tonight..> I am going to upgrade my lights to metal halide from power compacts. I have noticed in some of the online retail stores that there is a double ended metal halide lamp that I haven't seen too much of. How effective are these compared to the more popular mogul based lamps? Do they run hotter? Do they use more or less electricity? Have you ever used these type of lights? If you have how, in your opinion, did they perform? And, more importantly are they less expensive? Thank You for taking your time to answer my questions.  John <Well, John- let me start by telling you that I both use and recommend the double-ended halide bulbs. They are quite efficient, provide as much, if not more intensity and PAR than many mogul-type bulbs, and come in an ever-increasing range of wattages and spectra. The bulbs do run at a much higher temperature than moguls, but require electronic ballasts, of which there are many to choose from these days. Electronic ballasts tend to be a bit more efficient than the magnetic type ballasts. They do come in various wattages to suit many applications. Of equal, if not greater importance as the bulbs are the pendants that one employs with them. Many great models are out there for double-ended, by reputable manufacturers such as AquaMedic, PFO, and Sunlight Supply. I've seen a number of studies by serious hobbyists, such as Sanjay Joshi, which confirm outstanding results with double-ended bulbs when used in a well-designed reflector, and paired with a good ballast. Do a little research on various e-tailer's websites to see what models are available. There are a wide variety of prices, but on the whole, I'd venture to say that D/E bulbs and pendants are a bit more expensive than moguls, but worth the difference, IMO. Hope this helps! Regards, Scott F.>

Double-Ended Halide Bulbs (Cont'd.) Thanks Scott, <You're quite welcome!> A few more questions if you don't mind.  Can I take one of those metal halide pedestal lamps and convert it?  If not, why not? John <Well, that's a common question, and a lot of the answer has to do with the fact that pedestal lamps are not designed for aquatic applications: First, they are not made for moist and harsh environments. Second, they do not have reflectors to assure that light is being properly directed into an aquarium. Finally, the bulbs are generally not of any spectral quality that we'd want to use with aquariums. Best to stick with those products designed specifically for aquarium applications! HTH Regards, Scott F>

Bring On The Blues! (Halide Bulbs, That Is) One last question....For Today at least... The bulb my Aqua Medic light came with was a 150 watt 10,000 K bulb made by Aqualine <An excellent bulb!> Does this type of bulb, being that it is the only thing I can now fit over my tank, make corals fluoresce, and will it support the growth of corals and coralline algae...or is there a different manufacturer of bulb that has more blue spectrum in it? Thanks Guys <Well, the Aqualine 10000k is one of the best all-around halide bulbs available, IMO. It has an excellent PAR value, gives natural color renditions, and will definitely grow many corals. It will generally not fluoresce animals. For that, you'd want to either supplement some actinic lighting (VHO or PC is fine), or use 20000k bulbs (In fact, Aqualine just came out with one here in the U.S.). Do  keep in mind, however, that many 20000k bulbs do not create the same level of growth with corals that a 10000k or 6500k will, but the colors are pretty cool! Personally, I like the 20000k look! Hope this helps! Regards, Scott F.>

Metal Halide Bulb Options Hi all, <Hey there- Scott F. here  today!> Thanks in advance for all the answers you have provided in the past.  I am looking for a recommendation between Ushio vs. Hamilton 175 watt MH bulbs. Any insight would be greatly appreciated. Thanks, Andy <Well, Andy- it really depends upon the specific bulb that you're looking at. The Ushio 10000k bulb has a nice color, respectable performance, and a good reputation among hobbyists. Hamilton is better known for lighting fixtures, but does offer a number of bulbs. If it were me, I'd go on the WWM Forum and see what your fellow hobbyists think...Lots of different opinions out there. Enjoy the research! Regards, Scott F.>

Playing With Fire? Hi, I wanted to know if I could put a HQI bulb of any appropriate Kelvin range onto a plain regular regent 300 watt quartz Halogen floodlight. Is this possible. I intend in doing this if so. Because the current bulb is far to yellow and unsuitable for a reef tank.  My name is Ray. Thank you. <Well, Ray- I'd caution against trying any unknown bulb/fixture ballast combos unless you talk to the manufacturer first. You could cause a fire- or worse! Err on the side of caution! Regards, Scott F.>

Metal halogen question Hello everybody I hope all is well. <Hi Chris, MacL here> I had a question about lighting my saltwater aquarium.  I recently got a new job where we use low voltage out door lighting with mr16 halogen bulbs. I was wondering if I could use mr16 for my various tanks fresh and saltwater. <I believe that you can but you run several risks.  Metal halogen can explode if they get wet and I'm not sure they will have the correct spectrum.> Do they make bulbs for such applications? <You'd have to talk to the manufacture about spectrums that they have. I might add though that they did use halogen in Japan but they had them elevated WAY WAY WAY off the tank.>  I haven't been able to find anything out about this and I know you have way better sources of information than I do.  Thank you in advance for any help.  <Hope that helps MacL>

MH lamp newbie thank you very much for your input it is nice to see there are people who still care. <<You are quite welcome.>> I ended up draining the tank removing all the strata and starting over, the pvc glue bled into the tank. <<Oh?>> all the inhabitants are doing great ph is a steady 8.2. <<Good deal.>> I am a marine nut and love this tank more than my wife so she says:). <<Careful, or you may have to sleep in the fish tank.>> I have gone to a metal halide and have a ? about it. <<Ok.>> I got an Osram 175 watt bulb am running and the tank seems to love it but I cant tell the k rating I don't want to hurt them with to low a rating. can u help???? <<I can help only slightly... Osram is a brand of Sylvania which makes street-grade metal halide and high-pressure sodium lamps for lighting parking lots and the like. As far as I know, none of the Osram bulbs are really appropriate for keeping corals... but, similar to your last mail and my last statement/answer... what are you keeping that requires this lighting? Fish do not 'need' metal halide lighting, and neither do most LPS corals - if you are keeping clams and/or SPS corals, then you should make every attempt to procure the appropriate bulb. Lighting isn't really something you should approach haphazardly. Here's a link you should read that will help:  http://www.wetwebmedia.com/marine/setup/lighting/index.htm >> thanks a million again keener <<Cheers, J -- >>

Metal Halide Hey there- I have been reading through the FAQ's and still don't have an answer to my dilemma.  I have a 125 gallon aquarium with 3-175 watt CSL metal halide retrofits.  The tank is only one month old and came with the CSL 10K bulbs. I also have 2-96 watt power compact actinics.  The tank doesn't look very bright and appears too blue for my taste.  I am looking to switch my bulbs. Would you recommend switching to a different brand 10K such as AquaLine or Ushio to provide a more crisp white rather than blue?  Or should I switch to Iwasaki 6500K?  Would that appear to green or yellow in appearance?  I am looking for an overall white with a little blue appearance w/ the actinics. I have mostly soft and LPS corals with a few SPS.  I am looking to get more and more SPS and want the lighting that will support them.  I know many people have asked similar questions, but after reading the FAQ's I couldn't decide. Thank you very much. Josh <<Hi Josh, Thank you for writing, Craig Watson here for the WWM crew at the MACNA conference. I will answer with my own experience, Josh. I have a few 175 watt MH's that I run with VHO actinic, so this will be comparable.  One came with a CSL. I run all three with Aqualine's. For a whiter, cleaner look with a touch of actinic, I recommend Aqualine 10K bulbs. You will notice a marked improvement over the CSL 10K's. They may start and arc intermittently for a while, don't worry about it.  Keep them on and it works out. Champion may still have a special on them. If not check http://www.customaquatic.com Cheers, Craig>>

Metal halide question Hey there- <<Hi, JasonC here...>> I have been reading through the FAQ's and still don't have an answer to my dilemma. I have a 125 gallon aquarium with 3-175 watt CSL metal halide retrofits. The tank is only one month old and came with the CSL 10K bulbs. I also have 2-96 watt power compact actinics. The tank doesn't look very bright and appears too blue for my taste. <<Yeah... those CSL 10k bulbs are crap.>> I am looking to switch my bulbs. <<Do it.>> Would you recommend switching to a different brand 10K such as Aqualine or Ushio to provide a more crisp white rather than blue? <<If I were you I'd invest in the Aqualine 10,000 Kelvin bulbs - much less blue and I think very pleasing to the eye. The Aqualine are "German" lamps.>> Or should I switch to Iwasaki 6500K? <<Another option, but typically needs some additional VHO actinics to add some blue.>> Would that appear to green or yellow in appearance? <<A little yellow, perhaps.>> I am looking for an overall white with a little blue appearance w/ the actinics. I have mostly soft and LPS corals with a few SPS. I am looking to get more and more SPS and want the lighting that will support them. I know many people have asked similar questions, but after reading the FAQ's I couldn't decide. <<Well, now you know what I think.>> Thank you very much. Josh <<Cheers, J -- >>

Halides <sigh> If it's not one thing it's another. Now that I've decided to replace my 2 250W 10K MH with 2 175W 20K MH, to get the nice look of the picture you sent, I can't seem to find 20K 175W MH, Radium or otherwise-- minimum is 250W. Was that to what you were referring? They do sell a 12K 175W MH, which they claim has a nice blue tint to it...do you have any experience with them, in terms of light needed for corals/clams, etc.? I'm also going to have to find a buyer for my 2 month old 250W MH ballasts and bulbs, or my wife is making me sleep in the garage...:) As always, thanks... <hmmm... have you searched the internet for articles and work from Sanjay Yoshi on lighting? Do a keyword search on engines and message boards for his work. He has done recent studies of all of these bulbs. I really must defer to him if you want/need an opinion on the quality of light (PAR/efficiency). My original and best advice for optimal growth is 10K Aqualine bulbs for 175. Almost as good as daylight 6500 K Iwasakis at growing corals, but a much nicer/bluer color. Still... neither are as blue as Radiums> Arthur <best regards, Anthony>

Downsizing Halides :) Anthony <cheers, Ralph> have been thinking about changing from Iwasaki 250 watt to Ushio to get the green out <understood and agreed. Iwasaki is a fine lamp but some of the older ones were distinct yellow/green. The new ones are markedly less (they took the unnecessary green component out), but still... the Aqualine and Ushio 10K lamps are handsome blue white colored... actually rather white> and will have to also change the PFO ballasts. I could change to a 175 watt at the same time the 180 gal reef tank has water 20'' deep and 7'' from the top of the water to the bottom of the metal-halide lamp. <considering the wonderfully shallow depth of the display, I do believe 175 watt halides will serve you well and not let you participate in the shameless waster of electricity (if not stress of corals) that the popular use of 250 and 400 watt halides over tanks (less than 30") have seen recently> I hope all is going well. RGibson <and the same with you, my friend! I am keeping busy as always. Two articles a week and working on two books at the same time. It keeps me off the streets <G>. Kind regards, Anthony>

14000k MH lamps Hello all, Anyone tried the 14k halides? ... I can only find them so far through Hamilton but would like to hear some opinions thanks folks. <check the message boards... this company has had their share of customer service and QC issues/complaints. Beyond that, bulbs over 10K have been demonstrated to have excessive blue measures of light at he expense of useful (to corals) daylight. So, if you like the blue color more and you are willing to sacrifice a little coral growth/health for it... perhaps 14000K is good for you. Personally... I am certain that there is no need for coral health to exceed 10, 000K. Even 6500K Iwasakis have enough blue for coral health! (Yoshi 2001/2002). I have said it hundreds of times over: Aqualine or Ushio 10,000K lamps are the best all-purpose bulbs (testing/performance, longevity and aesthetics). Best regards, Anthony>

New Metal Halide Light Guys, I need help. I just got delivery of a new Custom Sea Life 175 w MH/ 2x65 w PC light fixture.  Up until this moment I have only had PC fixtures totaling 225 w on my 72-gallon bow front reef tank.  Well, anyway, I was expecting a very bright light from the 10,000K MH bulb, but it appears quite dim and very blue.  Is this normal?   <Unfortunately for this bulb (custom SeaLife) it is normal. Definitely shop our WetWebMedia.com sponsors for a Aqualine 10K bulb to replace the CSL. I have one I use to hold shelf space....> Is there a break-in period or a specific break-in regimen for a new bulb or ballast?  Or is this fixture defective and need to be returned.  I realize it is difficult to define "dim,"  but the light is definitely weaker than with PCs.  Any advice you can offer would help.  Thanks. Scott Ball <Sorry Scott, the stock bulb is junk. The AB 10K are much better. They have been on-sale on-line lately for decent prices.  Use the CSL as an emergency replacement, it's barely worth that!  Hope this helps you out!  Craig>

MH Bulb Replacement Its about time to replace my MH bulb and as I've been shopping around I noticed there is a considerable difference in price between American bulbs and German bulbs. What is the difference besides the price?  Thanks again,  Josh <there have been several independent and recent comparative studies done on MH lamps. The best perming bulbs/brands were Ushio 10K, AquaLine 10K and Iwasaki 6500k. None need blue actinic supplementation either. For more information, search/seek the work of Sanjay Joshi and Dana Riddle of Riddle Laboratories for starters. Best regards, Anthony>

Re: 250w 20,000k  Bulb HQI Radium Mogul Base <Khanh Do... I noticed your query in the WWM mailbox and have a little bit to add. First of all. The HQI Radiums have demonstrated outstanding performance and longevity among halide bulbs... it is one of the best. Lifespan for most halides (CRI/PAR integrity) is easily 2 years for most... some go over 3 years. For more information on this and all currently popular lamps... do keyword search the internet for articles by author Sanjay Joshi. (look on the message boards for links to his name/articles too). He has done some fine independent studies on bulbs and brands. Best regards, Anthony>

Metal halide bulb situated close to PC's...will they burst? Into Flames! Dear Consortium, I have a 55 gallon reef tank with standard type wooden canopy up top.   <custom made?> Drilled into lid of canopy I have two 96 watt PC bulbs with reflector. I also have a 250 watt Iwasaki Metal Halide bulb mounted in-between the PC bulbs on a model base fixture and bracket. <what?!?! A 250 watt halide on a 55 gallon? Are you out of your mind <G>. Trying to make lava? Stopped doing heroin this week? Or are you simply are that rare aquarists exclusively keeping shallow water Porites and Goniastrea species to need this much light on such shallow water? Sheesh, bud... this is dangerous from several different perspectives not the least of which is photo-inhibition of most of your corals by the time they are a year old if they even live that long under these lights> Due to the halide fixture being a bit long, it used to hang about 2" below the PC's, but I've been having>problems with the return spitting out water and air near the surface, and this caused a splash real close to the fire hot halide bulb. <a problem indeed> Today I noticed that the center brace of my tank is partially melting due to the halide lamp.   <not surprised, bud> IT's because of the darn bracket it's installed in.   <heehee... not the reason> The bracket is too long and hangs too low on the canopy lid, so i trimmed it by about an inch or so, <the story just keeps getting better <G>> so it'd be a little higher from the center brace of the tank, as well as from the water splash and water itself. My question is this. Now that the metal halide is about 1/2" away from each of the 96 watt PC bulbs, <Doh!> will the heat from the halide bulb cause the PC bulbs to burst? <possibly... if the whole fixture does not catch fire while you are at work first for lack of engineering and airflow (as evidenced by the heat accumulating enough to melt plastic> I'm really afraid that this can occur.   <and you should be honestly> I don't have any more room under my canopy to spread the PC's apart wider then they are.  They are pushed as far apart as the canopy top and reflector would allow.   <its simply a bad design from Go> the halide lamp hangs about 1/2" lower (nearer to the water) from the PC's when the hood is down. My MH lamp is about 4" away from the water surface with the canopy shut.   <oh dear heavens...> I know this is close, <actually, its VERY close. 6-9" is recommended for 150-175 watts... further for 250 watt> but I'd imagine that's quite common/standard with tanks/canopy of this class.   <not even in the ballpark of safety. Do seek a professional canopy of approved (engineered) DIY design my friend> I've even raised the canopy up on 1 1/2" wooden blocks to the maximum height (can see the entire black plastic brace that surrounds entire tank top).  I cant raise it any more than it's already raised. Please advise <not sure what to say there Steve... the whole thing is crap. A fire hazard. I wouldn't fall asleep in that house. Do check any willing inj that canopy for dry-rotting from the heat too. Some very serious concerns here. You need to gut and re-configure this lighting system. Please seek the counsel of a local professional and/or aquarium society perhaps. This is beyond our ability/responsibility for advice to be realistic. Best regards, Anthony>

Re: metal halide bulb situated close to PC's Anthony, >Thanks for replying. <no worries... but if you send and more or any longer messages this week we will officially be married in three states <G>> My canopy top is the typical one you'd see at the LFS that comes with all 55 gallon All-Glass tanks. <Yes...made for fluorescents... not MH. A risk indeed> It's a white oak canopy top and stand...pretty standard size.  The stand has two doors on it which houses two acrylic sumps with return pump and pump to adjoining refugium in another cabinet. The canopy top has a 40" long reflector that initially housed just two 96 watt PC bulbs. Exactly> Just so you know...there's only one 50-50 bulb (daylight and actinic) and one double blue (faint actinic fluorescing) bulb, so the PC bulbs themselves aren't all that bright on their own (mostly blue light, and faint at that). <OK> I purposely added mostly blue actinic type bulbs to tone down the yellowing that the 6500 K Iwasaki bulb emitted.   <understood and agreed> Now I have a very nice balance of color.. <and a warm fire to toast marshmallows over <G>> just the right amt of white and blue to fluoresce the small amt of polyps, mushrooms, foxtail coral and a few other lower light species.  Mind you, the MH bulb is in the center of tank, and these low light creatures are on the very edges and at the very bottom of tank, shaded by overhanging live rock. so they are pretty much in the shade.   <OK... if that's what gets you through the night keeping a 250 watt lamp 20" over them...heehee> The MH really only shines bright in the center of the aquarium, and being that I have that crappy black plastic brace in the middle, the halide casts a shadow down the middle to boot, so I suppose that area's prime for a small lower light coral as well. <no comment... would simply like to see LUX readings to agree. Possibly correct> Anyway.. In the canopy, on each end I have computer fans drilled into it, as well as the back of the canopy is about 4" away from the wall and is completely open for air circulation.  I feel that due to the MH mogul bracket I received from hellolights.com, being so darn long, that it made the halide lamp hang a good 2 or so inches down from the PC's.. dangerously close to the center brace, and melting it to a degree.   <Hmmm... are you sure the problem isn't the mogul base, but that the canopy simply wasn't designed for this MH application?> But i caught this in time, and have since trimmed the mogul bracket back so that the halide now is inline with the PC bulbs and not so far below them near the water.  I also raised the canopy up on blocks as high as it can go. <is there a question anywhere in sight of the finish line here? Heehee...> My tank water isn't hot........75 degrees + or - <OK> The metal halide was simply too close to the center brace.  I figure by raising the canopy to maximum, and getting the halide bulb higher from the center brace, maybe it wont get as hot. Do they make any type of fan that I can clamp onto the back of the tank that would blow air straight at the MH bulb?   <there must be something, but I would reiterate my previous advice... buy or build a proper canopy for MH. For your safety at home if nothing else> They make clamps that are super strong, at Home Depot. with rubberized grippers, so I'd feel confident the fan wouldn't fall into the water... <somebody shoot me...> not unless an earthquake occurred in South Florida.   <scratch that... slap me silly> I did all the wiring myself on the lighting.. <back to shoot me please...> used some serious oil, gas, heat resistant wire and covered it with electric tape.   <did the though of using proper wiring conduit ever cross your mind bud?> There are NO wires anywhere near the MH bulb whatsoever...just the two that exit the mogul base and go straight down the line to the PC's then to the ballasts in an adjoining cabinet. <and that brief exposure to heat/light, etc stands to degrade their non-UV stable shielding (original, toed, or otherwise... have seen this> You say that 6-9" away from water is recommended for MH bulbs.   <yeppers> That would mean that in almost everyone's setup with a canopy type top, that the PC bulbs themselves would even be further away than 6-9" <Huh? Dude... buddy. We need to get you out to the conferences and aquarium society meetings to show you all of the nifty products out there. Clips, feet and stand-offs to mount fluorescent lamps properly at no more than 3" off water surface while MH is fixed above 6". Many options here in a professionally made canopy> because they are thinner tubes and would be mounted closer to the canopy top than the halides would be. I'd imagine PC bulbs so far from the water, then having to shoot down 22" or so thru water may really diminish the spectral intensity of the light. <correct if it were so> Ok, so there you have it.......another dilemma. <no worries bud... just need to get you shopping.> Oh one more thing...my MH lights are on for about 6 hrs a day. <good to hear... helpful, but still not safe from photoinhibition with some species> Small 20 watt accessory bulb comes on first for an hour, then one PC pops on the next hr, then another PC the next hr, then the MH bulb the next...and they shut down in reverse order.  All are on a separate digital timer.  All connected to Ground Fault sockets with surge protectors and 16 amp extension cord. Thanks for all your advise. <and sarcasm <G>> Steve <fatigued... Anthony :) >

Light Distance Hey Guys, What is the minimum distance off the water for MH bulbs? <6-9 inches for 175 watt bulbs is appropriate... no higher. Slightly more for 250 watt> I recently acquired used fixtures with 250 watt Iwasaki's and would like to mount them in my hood. I can mount them at 5.5 inches from the water without cutting the hood. <its rather close unless you plan top keep only shallow water species (SPS and clams?). Your tank must also be deeper than 24" )pref 30" or deeper) else you likely have too much light for safe coral health in the long run> I will cut if I have to but I usually like to keep things simple. Thanks again for your help. Tom <best regards, Anthony>

Re: Light Distance Finessing an anemone and corals Anthony, I see you're also a night owl. <heehee... yes, indeed. Sometimes there are just too many good old movies on late <G>> About the anemone, is there another less hostile anemone that I can put in with the reef? <because of their motile nature, all anemones are potential disasters when mixed with coral. None are truly recommended. Ritteri is one of the worst and usually moves often> The only other (not including QT) salt tank I have running is a 55 predator with 5" Volitans Lion, 4" Porcupine Puffer, 8" Chainlink Moray, Serpent Star, Choc Chip Star, and Large Condylactis Anemone. <that tank could actually work fine with a MH and without the puffer and other anemone> (The tank will be upgraded to another 125 later this year) I doubt that I could put a Ritteri in that mix as the lights would hurt the Lion. <no harm to the lion at all my friend. A reef fish and nocturnal at that> (not to mentioned overcrowded already). If I were to give up on the Ritteri (LFS is very friendly) should I raise the lights a little at that point? <yes, indeed. Toward 10" would be about right IMO> And again thanks / sorry to be a pain. Tom <no trouble at all, bud. We're here to help :)  Anthony>

Metal Halide Problems I am a beginner trying to get reef system up and running...2 actinic lights and 2 MH bulbs. 1 of the MH will light for a minute. then cause the ballast to flick a few times and then go out. I have tried switching ballast with working light to no avail. This bulb was difficult to screw in as compared to other bulb. I do not know how fragile these bulbs are. Any suggestions? I hate to buy a new one but will if I have to. <Well, here's the deal...There are a number of different bulbs that do not run on certain ballasts (for example-many 20000k bulbs). Also, the difficulty that you may have screwing the bulb in may mean that you have the wrong kind of base for your fixture! There are "medium" base bulbs and "mogul" bulbs, which fit into different fixtures. You need to Contact the manufacturers of the bulbs and/or fixture that you have, to assess what will work. Don't give up- but do read up! Good luck! Regards, Scott F>

Halide Bulb Selection I currently have 2 10k Ushios halides with 2 VHO actinics, the color is good but it is getting at the end of the halides life and I want to go to a bluer bulb. I am not sure if I want to go with 20k as this might be too blue, I like the look of the 12k sunburst although have read some bad reviews. Will the 10k Blueline or Aqualine make that much difference over the Ushio or will they look about the same? I have a mixed reef with LPSs SPS, clam, anemone and Acropora, I know I will have to acclimate slowly to a new bulb but I have been at me whit's end for weeks on what to do. Thanks, Scott 90gallon,48x18x24 2- 175 10k 10inches off water Ushios 2- 110 actinic VHO 6inches off water----I am pretty sure that if I had the actinic closer to the water it would help with color more, but my hood doesn't permit any closer. <If you are looking to go a bit bluer, you might look at the Aqualines. Fairly natural looking light in the 10K's.  Craig>

MH bulbs Quick question. I just want you to clarify the difference in MH bulbs concerning the different wave lengths and practical info for the tank. I believe the 5,500k, 10,000k, etc. are the major wave lengths of light these bulbs put out. A 5,500k bulb would be more in the red spectrum and be a day bulb and the larger the wavelengths the more actinic the bulb, correct? To wrap it up, what do you want for your tank? Does a 10,000k "upgrade" bulb include all a 5,500k bulb would, meaning it is always better? Or do you need a variety of bulbs to get the full spectrum? Thanks, Jonathan >> Hmm, the temperature rating (black body radiation) of lamps is not really that far off described as "wavelengths"... The lower temperature lamp rating's type/blend of irradiation not subsumed by the higher... and a mix of lamps, with ratings of 5,000 Kelvin or higher are of use in different situations (higher with greater depth of water, more "high" light using species like tridacnid clams, SPS corals...)... as well as "for looks". You don't need a mix of lamps to get full spectrum lighting necessarily... Most size, shape, purpose reef systems can "get by" with lamps of actinic and 5 to ten to twenty K. rating...  Bob Fenner

Metal Halide vs. Mercury Vapor Hi Bob, it's me again. Can metal halides bulbs be used in place of a mercury vapor bulbs or sodium bulbs? Thanks again. Aldrin <In place of? Functionally, yes, of a certainty... MH produce the most useful illumination per kilowatt of electricity consumed... most useful format/production for "deeper" (two foot plus) tanks... barring problems of light distribution, heat production... Mercury vapor and sodium are not recommended... due to spectral production...  Can be used in same fixtures? Don't think so... see the manufacturers/distributors of such listed in the Links pages of www.WetWebMedia.com for specifics here for the units you own. Bob Fenner>

Re: Metal Halide vs. Mercury Vapor Hello again. Thank you for your prompt response. The second part is what I meant. I went to Home Depot last night and the guy mentioned metal halide bulbs can be used on a mercury vapor fixture. Thought I'd confirm it with the man (that's you!) himself. <Once again... you can appreciate my alacrity here... I cannot state carte blanche that this can be done (on the internet)... do know of folks who have done so, others who have written pro statements re... but the electrical requirements and heat generated by these types of lighting/lamps is different... I personally would not use the vapor fixtures for the MH lamps... NOT. Do write Perry Tishgart at Champion Lighting, in fact, gladly copy this thread and send it to him and ask his opinion... he's honest and very competent in this field. Their URL can be found in the Links pages of www.WetWebMedia.com> My other question is how far should the metal halide bulbs be from the water surface? I built my own canopy and I believe the cover sits about 6-7 inches high. Farthest distance from the water will probably be around 3 inches once the bulbs are installed. What do you think? <A foot is better... for light dispersal, safety from splash/spray...> Thank you so much. Aldrin <Be chatting my friend. Bob Fenner>

Metal halide! Hi Bob, How are U these days, I was just wondering do you work with FFExpress, because from what I remember you been doing the FAQ's in the past 5 years that I can remember!  <Yes... through all the various manifestations of FFE I (and Mike Paletta) continue to help answer their hobbyist's queries> Anyway you been doing a excellent educating people. My local LFS here in Northern CA mention that there are a big jump on a reef hobby in the past 2 years. I think I can't believe that!  <Me neither... seems to me there are a dwindling number of shops every year...> Anyway my question is why so many people choose German MH vs. USA, besides they last longer and they are smaller in diameter. Do they have better intensity (PAR) in a long run or is it crispier white as some people say or ?  <IMO/E no... strangely enough, in Western Europe, many folks prefer the American and oriental lamps...!> My other question is does MH really burn the fish according to the LFS here in Mountain View CA?  <Hmm, well... depends on what you mean by "burn"... but yes to sudden changes or too-intense lighting causing troubles> Is there difference or advantages in Kelvin besides heating my tank even more/ besides color for better looks on the corals and fish?  <Only to an extent... as you've stated the acronym, PAR and related measures and intensity are what matters functionally... beyond the threshold of about 5k K. in temperature> Maybe this is a better question, Is there photosynthetic Advantages? Thanks in Advance! your a great teacher to all! Be chatting! <Thank you my friend. No photosynthetic advantage beyond what I have stated. Bob Fenner>

10,000K or 12,000K Hi Bob, Before I start with my questions, I just want to let you know how wonderful it is to be able ask a person of your caliber and reputation questions. As usual, thank you for the quick replies. <Glad to be here> On to my questions... if I use 12,000K metal halide bulb, do I need to supplement it with any actinic bulb. <"Need"... hmm, likely not... some types of organisms do benefit from the extra intensity in the wavelengths these produce... depending on the sorts of life you have, their placement/depth in the system... probably only a few percent advantage...> If I need to use it, most likely, I will be using fluorescent tubes. Can fluorescent bulbs (VHO or not) withstand the high heat of the MH bulb?  <Mmm, not directly... as in the MH placed above, near them... but with parabolic reflection... you can set the actinic/s back, front...> My last question, if no supplementation needed, which one do you prefer, 10,000k with actinic, or stand-alone 12000k? <The 10K> Thank you. Sincerely, Aldrin <You're welcome... Perhaps you can/will write a definitive article on the subject of the utility of such light/lighting for the hobby? All the background you would need is available currently on the Net. Bob Fenner>

Lighting Hi Bob I would like your opinion on a 250 watt metal halide bulb. I have 65k"s on my reef tank at the moment but would like to use 10k"s instead. The color I am looking for is a bright white blue color. Out of these 3 manufacturers which one would give me the greatest white blue color? Aqualine Buschke, coral life ,or blue line? <Mmm, in order: Aqualine, Blue...> I am ordering from champion lighting. almost think that the Blue line is there product. I also want to thank you for your excellent site. I know it has to be a pain answering all of the questions from here and FFExpress try to look over both sites before I mail you so I don't look like an idiot for not trying to resolve my questions from these sites. Thank you once again! Take care. <Thank you for your participation. Bob Fenner>

Lighting a very deep captive system Mr. Fenner, I am in the process of purchasing a rather large aquarium. One 84" in depth.  <Wowzah, this is a TANK!> The company supplying the tank, Reynolds Polymer, claims that it is impossible to maintain live rock at such a depth and wants to sell me a fiberglass reef. <Hmm, well... my or an actual rebuttal might be that "live rock" is found in the wild at much greater depths... But having another tank tied in... is a good idea> My question is, what type of lighting, what K and wattage, and what spacing is necessary for the successful maintenance of a Fiji Rock reef. No corals etc, will be part of the reef. Any help will be greatly appreciated. <10,000 to 20,000 K for the very deep system... something above 5,000 Kelvin for shallower... wattage for the big tank in the 1 kilowatt size... the smaller, down to 175 watts, to 250 to 400... Much more to talk over my friend. Please take a look on our site, particularly the articles and FAQs on custom tanks: http://WetWebMedia.Com/tksstds.htm http://WetWebMedia.Com/dessysart.htm Bob Fenner> Re: Lighting a very deep captive system Mr. Fenner, Understood so far but what spacing should I do? Does a light cover an area 4x4, 6x6, etc. In effect I am trying to estimate how many lights will I need, and how bad is the electric bill going to be. Thank You very much, George <Hmm, yes to the light covering a given space... best to set nearer to each other (like two feet apart) on the very deep tank. The electrical consumption can be calculated by the watts consumed per fixture/lamp multiplied by the number of such fixtures/lamps which will give you the watts consumed per hour, multiplied times your kilowatt hour charge (likely about ten cents... unless you're in California)... you can get from your electrical bill... and then multiplied times the number of hours per day, week, month you intend to run them... Ex. one 1 kilowatt lamp run an hour uses about 1 kilowatt hour of electricity... costing an estimated ten cents per hour to run or at ten hours a day, about a dollar per day, thirty dollars per month... If you pay thirty cents per kilowatt hour (for ex.) you'd be charged near a hundred dollars per month for this one light. If, when, where in doubt, call the utility company. Bob Fenner>

Halide bulbs Hi Bob Hope you are doing well today. I would like your expert opinion on 10k halide bulb's since I don't have any experience with the different companies. I have a CSL 2 250watt halide ,pc actinic hood. I would very much like to use 10k bulbs but I don't know which company to buy from to get the best bright white and a tint of blue for my tank. FFExpress sells the CSL bulbs, champion lighting sells, blue line Aqua line, and Coralife, Can you tell me which company will give me the nicest color I am looking for?/ <Hmm, well stipulated that the actual manufacturers of lamps are none of these companies, and that they can/do very quickly at times switch to "other brands" themselves... At this time (8/01) the CSL ones are my choice> Also, if there is a better company that I have not listed, please let me know. As always, great thanks. Don't work to hard, I know that is easier said than done. Take care, thanks again <This can, could get very involved... Again, know that the companies in the hobby interest "re-label" their lamps... they're made by other people... My best advice is to use the various BB's and Chatrooms (ours: http://talk.wetwebfotos.com/) to ask other hobbyists for more specific, timely advice here. Bob Fenner>

Lighting upgrade, changes Hi Bob Sorry to bother you with another boring  <Hey, are you calling me a pig? Boar or boring!> lighting question. I have been using 65k 250watt halides on my tank. I am going to be changing them to the 10k"s.The 10k bulb's put out less PAR than the 65k"s I believe. <Mmm depends on make, model.> Should I increase the photo period from 8hr"s to 10hr"s to compensate for the lost PAR??  <Ah, a good idea> My tank is a Berlin system. It is stocked with all of the usual SPS, LPSs and soft corals, swell as 200 lbs. of Fiji rock and 150lbs of live sand. As always great thanks. <Do take care to "grade into" the new lighting/lamps, perhaps by shielding part of the area with a "shade cloth" or elevating the fixtures initially... easy to burn your livestock with these changes. Bob Fenner>

20'000 K halide bulbs Hello Bob, one question regarding 20'000 K metal halide bulbs. I'm at the moment using three 250w( two are 20'000K and one is 10'000K) metal halide bulbs and 4 actinics tube and I'm still getting that yellowish shade in the tank (it's not that terrible, though...), I'm tempted to replace the only 10'000K with a 20'000. <I would try a bit of activated carbon first... in your filter flow path... then look into another brand of 10K lamp...> how bad would this be for the corals? <Not bad... but do "phase in" the new lamp in case of replacement... like an hour a day for the new one...> They do not yet sell any VHO bulbs here in the UK, so it would mean using 5 or 6 actinics tube to get that blue effect and it gets somewhat complicated. <Mmm, do ask on bulletin boards (our chatforum: http://talk.wetwebfotos.com/ about makes/manufacturers... Perhaps give TMC (Tropic Marine Centre: http://WetWebMedia.Com/tmcpropc.htm a ring and ask them whose lamps they suggest for your electrics. Bob Fenner> let me know, thanks Stef.

Lighting (switching out temperatures for MH lamps) hi bob I have a question on lighting I have a 150 gallon tank dimensions are as follows 26inches high 6foot long bob I currently have 5 175watt metal halide pendants above the tank I enjoy keeping stony corals Acropora and so on I was wondering what would be the best bulb set up in the pendants I currently have all10k bulbs in them should I go with some 65k in some pendants thank you bob for taking the time to help keep up the good work your books are fantastic. thank you Todd <Mmm... a bunch to say/state. I would change out at least two, if not three of the lamps to the 6,500 Kelvin temperature... more for looks on my part... Keep the old ones if they're still good for re-use. Bob Fenner>

MH bulbs Hola Bob <Hi there. You have reached Steven Pro, as Bob is out of town for awhile and he asked Anthony Calfo and myself to pitch in and help.> Edgar, from Mexico again :) I'm getting ready for buying my MH bulbs to replace the ones I have. Right now, I have 2 250 watts, 12 000oK sunburst bulbs and I'm really happy with them. However, I'm wondering whether I should try with other bulbs and I was thinking about either a 10 000 K German or Aqualine(?) <Aqualine Buschke, very good bulbs> bulbs or the 20 000oK German bulbs. So, here are my questions I thought I read somewhere that the 20 K require a special ballast? Is it so? Have you heard something about it? If not, do you suggest me to go for them? Do you suggest to get and try the 10K bulbs or should I stay with the 12K?. In case you suggest me to try the 10 K, which brand do you recommend? <Of the brands and color choices you spoke of, I would pick the 10,000K Aqualine Buschke lamps. I have seen these used on several tanks with very good results. Do read up on the various spectral output comparisons by Sanjay Joshi, Dana Riddle, and Richard Harker. Check out the site, http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/aquarium.html and Marine Fish and Reef 2002 Annual by Fancy Publications.> thanks a lot Nos vemos Edgar

Lighting Do you know where I can get the perfect hood for the halides that has 2 sockets built in or do I have to get 2 separate pendants? <There are various manufacturers of canopies that have MH socket with NO, VHO, or PC actinics. I know Champion sells some, look around for others.> Wouldn't the Ushios bulbs give me a blue tank? <Bluer than the Iwasaki's, but not blue.> I rather have a look that people describe as shimmering like a shallow reef or does the Ushios give me that look. <All MH's have that shimmering effect.> I really appreciate all the help you are giving me. <You are welcome. -Steven Pro>

MH or no? Dear WWM Crew, I want to thank you for your previous precise/quick responses. You guys are doing a great job!  <thank you for your kindness in saying so!> I have a few questions regarding switching my lighting application with the intent to incorporate it for a bigger tank in the near future. I currently have a 90 gallon reef tank for 3 years that is powered by 520 watts of retrofit power compacts (PC). My livestock are mostly LPS, soft corals, and one bubble tip anemone. I am currently considering switching to 2x-250 watt 6500K or 10,000K metal halides (MH) in conjunction with 130 watts of PC actinic.  <forget watts....not even a fair comparison in this case... a Luxmeter at 12" will show you that the difference between 520watts of fluorescent light and 500 watts of metal halide light are night and day!!! MH penetrates deeply and that is why it is such a great deal (bang for the buck). However... 250 watt MH will bleach many of the present and accounted for LPS without a lot of work in acclimation for you. Not to mention adding the other 130 watts of PC actinic (cool looking but not necessary with even the 6500K Iwasakis other than aesthetics. They have plenty of blue for symbiotics on a spectral chart> I am also planning to buy a 180 gallon tank in a year or two, so the MH will be incorporated with the entire 520 watt PC. I have some questions and concerns with the change to MH. <so far sounds like this set up will be more harm than good for your livestock... still, it would be a very nice outfit> First, I am afraid of the 2x-250 watt MH will burn my corals because some are placed very closed to the top. What are some method(s) of screening the MH light to allow the corals to adjust? Or is this too much light for the corals?  <yes... the latter my friend> Can I buy a 250 watt ballast, but use a 150 watt bulb for the 90 gallon tank now, and later switch to a 250 watt bulb when I buy a 180 gallon tank? The reason for buying a 250 watt ballast is because it offers greater flexibility/versatility when it will ultimately use for a 180 gallon tank, but I want to try MH now. <even later... if the 180 gall that you pick is not deep or packed with SPS, it is still too much light. A standard six foot 180 gallon tank would be better served by 3-4 175 watt MH for sift corals or LPS which are most popular. I have no knowledge of the bulb switching although it sounds unlikely or at least scary> Secondly, with regard to MH, I am undecided between the Iwasaki bulb vs. the HQI bulb. Are there any distinct advantage(s) between the two bulbs? <I have seen one study that pegs the Iwasaki as far and away the best choice for reef inverts in general> Furthermore, is there any ballast brand (PFO, IceCap, Blueline, etc.) or type you can recommend? I am researching through the differences between the standard core and coil ballast vs. the electronic ballast.  <the benefits of electronic ballasts are a figment of marketing imagination. And I have a distinct preference to avoid one of the above named. I will say that despite early R&D difficulties, Icecap has always enjoyed an outstanding reputation for customer service. I personally have had very good experiences with them> So far, the electronic ballast is much more efficient in terms of energy, heat, and bulb life.  <not even close to being true by one expert I am aware of (unbiased, unpaid and very convincing> But, I have heard some people mentioned that the electronic ballast is not a perfected technology yet. A lot of the electronic ballasts have a tendency to break down and/or not work properly. Is this true?  <I have heard an overwhelming amount of criticisms in this line... too much to discount it. yes> I saw IceCap have the electronic ballast that would fit my needs and I was wondering how reliable they are? Thank you for your time. Cheers, Dan <this is one area that I am content to say if it isn't broke don't fix it. A standard MH ballast costs $45-60, add a harness and ceramic socket and you have a workhorse that just might last more than ten years. It is old, tried and true technology). I wouldn't put my money on an electronic ballast to do that just yet or for some of those companies to be in business that long to back the warranties. IMO>

Re: MH or no MH--Follow up in stereo Hello, <right back 'atcha, Bub. By the way... the latest report of Bob's zany trek across Australia has placed him running amok in an enormous clear plastic hamster ball through the streets of Downtown Sydney... he says there's no better way to travel.> It always amazes me how quickly you guys respond...the entire WWM crew's dedication to this hobby deserves much praise!  <Grazie> To recap our last correspondence, you are in favor of the Iwasaki 6500K MH and a standard ballast.  <exactly... a very good all-purpose choice> I have follow-up questions in terms of wattage for MH, a reliable ballast, and acclimating my corals to MH. <for acclimation tips also look at my article on WWM: http://www.WetWebMedia.com/acclimcoralslight.htm> In terms of my 90 gallon reef tank, I want to include clams to my microhabitat, thus the reason/need for MH.  <would be nice, but not at all necessary... even the most demanding crocea and maxima species would live nicely in the top 10" under VHO and the like> Would adding 2x-150 watt 6500K Iwasaki bulb with 130 watt of PC actinic be more reasonable/applicable?  <actually sounds very nice and would satisfy most popular inverts (great for many Zoantharians, soft corals and LPS)>  What are some ways to allow my corals to adjust to the 2x-150 watt MH?  <all spelled out in the above listed article> Lastly, can you recommend a ballast brand that can operate the Iwasaki bulb (all I have seen are Ice Caps, and PFO---which I think makes Ice Caps)? <hmmmm... I'd have to look into that. I'm a bit out of the loop on all brands to comment> Again, thank you very much for your time. Cheers, Dan <kind regards, Anthony>

Hello, It always amazes me how quickly you guys respond...the entire WWM crew's dedication to this hobby deserves much praise! <Thank you very much!> To recap our last correspondence, you are in favor of the Iwasaki 6500K MH and a standard ballast. I have follow-up questions in terms of wattage for MH, a reliable ballast, and acclimating my corals to MH. In terms of my 90 gallon reef tank, I want to include clams to my microhabitat, thus the reason/need for MH. Would adding 2x-150 watt 6500K Iwasaki bulb with 130 watt of PC actinic be more reasonable/applicable? <That sounds like a good mix. Iwasaki's for photosynthesis and actinics to improve the aesthetics.> What are some ways to allow my corals to adjust to the 2x-150 watt MH? <You can temporarily have the lamps raised and then slowly lower them. Also, keep the MH's on for a short time period, say only two hours and add two hours every week until you have reached a desired photoperiod, about 10 hours. The PC's can be kept on for 12 hours daily. And lastly, you could try shading the tank with several sheets of vinyl window screen to cut back on intensity, removing sheets later.> Lastly, can you recommend a ballast brand that can operate the Iwasaki bulb (all I have seen are Ice Caps, and PFO---which I think makes Ice Caps)? <They are two separate companies as far as I know. You should be happy with either. I would refer you to various articles written by Sanjay Joshi in which he compares ballasts and spectral outputs, http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/aquarium.html> Again, thank you very much for your time. Cheers, Dan <You are welcome. -Steven Pro>

MH Lamps I was wondering if you could please answer some general questions for me. In plain terms, what is the difference between MH bulbs made in the US, Germany and Japan? <Not so much the country of origin, but the companies in those countries that manufacture/market the lamps.> Are some better than others? <Yes, just like anything else, some better than others.> How and why are they different? <Different spectral distributions for the most part.> Are the spectrums the same? <For some yes, others quite different even though many have the same designation, like 10,000K.> The prices are different so what gives? <I am going to refer you to the excellent works of Sanjay Joshi. He has done some pretty nice examinations of the various lamps by manufacturer.> Thanks! -D <You are welcome. -Steven Pro>

Metal Halides Too Close to an Acrylic Tank? Hi guys, I have to tell you that WetWebMedia.Com has been an excellent source of information so far. <Thank you. Be sure to tell your friends.> I think I may have been taken in by the guy at my local pet store, though. I'm moving up from a 65 gallon to a 180 acrylic, rough measurements 70L X 24H X 18W. The oak canopy he sold me is only 6" high, though. I'm concerned that mounting 3 metal halides under this canopy will put them entirely too close to the acrylic tank top. There will only be about 1 1/2 - 2 inches of clearance from the metal halide bulb to the surface of the acrylic. Isn't that too close? I'm concerned about possible damage to the acrylic itself. <Damage to the acrylic and to the animals is a very real possibility. MH's lamps are generally mounted 6" to 12" away from the top.> Also, I intend to place a lot of hard corals in this tank. Would you recommend 3 250W MH's, or 3 175W MH's? <If hardcore SPS, go with the 250's. If more of a mix with LPS and some soft corals, the 175's will do fine. SPS will grow well also under the 175's. Invest in quality lamps. Aqualine-Buschke and Ushio are excellent in 175 wattages. Those two along with Iwasaki's in 250 watts.> How about 2x6500K and 1x10000K? <For the 250's, I would use 3-6,500K Iwasaki's with supplemental actinic. For 175 watts, I would use the 3 10,000K Aqualine-Buschke's with or without extra actinic.> I will be using supplemental PC Actinic lighting, also, probably 2x96W. Since I am still early in the planning stages, any help/ideas at this point is GREATLY appreciated. Thanks for any advice you can give me, Will <Do read through the files and FAQ's for lighting for additional information. -Steven Pro>

HQI lighting Hello, I currently have a 120 gal reef (48 x 24 x24) with a variety of SPS, soft corals. Due to my 430 dollar a month electric bill (Thanks Gov. Davis!!) <$430...whew! Consider a cheaper hobby... like drug abuse> I recently removed the two 250 watt MH bulbs from the tank and replaced it with a 4 x 96 watt Power compact hood ( 2 actinic and 2 10,000 k bulb) and also have 2 110 watt VHO Actinics. .  <Hmmm... perhaps not a great savings all things considered. 400 watts of MH light compared to 400 watts of PC light are not the same. MH is far more intense=more bang for your buck. Your corals are getting MUCH less light (easy to confirm with a Luxmeter at the surface and even more so at 12" water depth> I also have a 300 gal marine fish only tank and had an outside 60 gal grow out coral tank which had the power compact set up I just mentioned. Anyways, by getting rid of the 500 watts of MH from the 120 in addition to breaking down the outside 60 gal, I lowered our electric bill by over 200 bucks!!  <excellent... but has less to do with the lights... perhaps as much or more with pumps/heaters removed> The corals in my 120 include: star polyps, colt, pink Button Coral, mushrooms, green finger, hammer coral, Fox coral and green pin leather. Anyways.... Some of the green corals (star polyps, green finger) have turned a little brown since I took of the metal halides. I have been told that I may have too much light which is why some of the corals are turning brown?  <yep... predictable. Lower light has stimulated the zooxanthellae (brown dinoflagellates) to increase their resident populations in symbiosis. a common and perhaps harmless change> I think that under the metal halide the green corals looked their best (had 500 watts MH, 220 watts VHO actinic and also 80 watts of regular flourescent)800 watts total now down to the 384 (pcs) and 220 VHO which is just over 600 watts. Now for the question. I would like to go back to metal halide supplemented by VHOs but want to go with a much lower wattage, like two 150 watt HQI dbl ended bulbs? <the double ended bulbs have got some great reviews> I am researching the HQI ballast/bulbs because it seems to be kind of new still and now a lot of info is known. I am still looking for the article by Sanjay Yoshi but have not found it yet.  <a keyword search of Sanjay's name on the Google search engine for WWM and abroad comes up with many hits for his work all over the net. Please explore the first link for his general homepage and the second link for one of his very good studies/articles. More o be had if you will explore: http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/aquarium.html http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/ballast%20comparison/ballast-comparison.html> Anyways.....is there a difference between a dbl ended bulb versus a screw type? I saw a 150w HQI ballast (made in Taiwan) it takes a screw type bulb. I have read and heard that the dbl ended bulbs burn brighter?  <they do have a great early reviews> I would just have to worry about the U.V lens? <usually necessary> I am considering going with the 300 watts of HQI metal halide supplemented by the 220 watts of VHO actinic and maybe additional 80 watts of actinic. I realize if I put back the 80 watts of actinic plus the 220 watts of VHO actinic I am back to 600 watts of light,  <hmmm... so many lighting choices, but I am content with tried and true solutions. All of the better rated "regular" MH lamps have been shown to have enough blue/actinic light and require NO supplementation. If you want a simple solution, choose 2 or 3 6500K Iwasaki 150 watts (or 2 250 watt lamps) or the same number of 10K Ushio or Aqualines if you like a bluer colored daylight. Extra fluorescent lighting will only be for aesthetics if you like> If I don't I am cutting back about 80 watts. But would the intensity from two 150 watt HQIs put out more lumens than the 4 x 96 PCs?? <yes... MH type bulbs in general are far more intense... better deals> I will be searching for some HQI ballasts (Champion Lighting, Hamilton etc....) to compare to the Taiwanese made one I saw at my local fish place. If you have any opinions about the HQI ballast/bulbs versus the electronic Ice Caps MH ballasts or standard coil/tar ballasts could you please share your opinions with me. <fine with cap and coils.. I am strongly against electronic metal halides based on published and yet unpublished reports I have seen. Misleading and inaccurate marketing of these products> Again, I am very concerned with my electric bill so I am thinking that by using 300 watts of HQI instead of the 384 watts of PCs may help and also make the tank look a little brighter and some of the green corals get their intense greens back? <correct> Thanks for your time. Kerry Kanno <best regards, Anthony>

MH Lighting I would like to know your opinion on Metal Halide lamps 175w. I am starting a 55 gallon reef tank and want to know what kind of lighting I should buy. <I would use some sort of fluorescent lighting, normal output, power compact or VHO depending on corals housed.> I want to put lots of mushrooms, polyps, soft and hard corals (a wide variety). I wanted 175w 14000K but champion lighting does not sell it because of some technical problem. What do you think about 10000K? <These color temperatures are mostly marketing.> I noticed two different kinds, Ushio and Aqualine. Any opinion would be greatly appreciated! <Both are very good, but I would not use MH's on a 55. MH's produce a great deal of light and can cover a 2' x 2' area quite well. Your 55 is only 12" wide. You will end up lighting a lot of your floor.> Also someone advised me to buy 2 175w 20000K for my 55 gal reef tank, what do you think about this? I want my tank to grow, grow, grow and to be beautiful and healthy! Any advice would be great! <Four normal output 40 watt lamps would serve you well for mushrooms, polyps, many soft corals, and LPS corals. For SPS corals, I would use four 55 watt PC lamps.> Thanks, Nattalie <You are welcome. -Steven Pro>

Affordable Metal Halide lamps and some questions Dear Mr. Fenner, <Actually, Steven Pro here taking his turn at bat.> First and foremost, I would like to congratulate you on your website. Very elaborate and detail oriented! I am on it everyday, trying my best to digest the plethora of information readily available. <Glad to hear it. If you ever have anything to share, please send it along. We always welcome other input and experience.> I have been in the hobby for approximately 8 months now and have been very upset with the general pricing on the lighting aspect of the hobby. Which made me research for deals and steal on the internet. Then, I chanced upon an "enclosed mini ballast system" called Sun System IV from a discount hydroponics store. Here are the specs: The Sunlight Supply Micro-Mini systems are complete lighting systems in which the reflector and ballast are integrated in the same metal housing. They are referred to as Micro-Mini systems because they are very small in size and only use 100 watts of electricity, but put out the high light output which H.I.D. lamps provide. The Micro-Mini systems feature an 8 foot grounded power cord, wire mounting hangers, and a powder coated housing. They come complete with a backlit on/off switch. They measure only 15"L x 13"W x 6" high. All lighting systems come complete with bulb. And the cost...tadaaa...$129.95 ! Pretty reasonable for a MH lamp. <Not too bad, but it is only a 100 watt fixture, which is not at all common in aquarium lighting. It will be difficult to find aquarium spectrum lamps.> Question: I spoke to the gentleman and he told me that the spectrum on the bulb is 6,500K which is a yellowish-greenish light. I tried looking for 10,000K bulbs but they cost approximately $85. <Fairly standard pricing for lamps.> I was also told that the 6,500K could actually stir up an algae party in my tank by members on Nano-reef.com. <Not true. 6,500 K Iwasaki's are becoming very popular with SPS keepers. They do appear yellow-green, but have a very impressive PAR value. Take a look at Sanjay Joshi's homepage for some excellent data on MH lamps and ballasts, http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/aquarium.html> Here are the specs of my tank: 1) 20G (24" X 13" X 12") <Only a 20 gallon tank. MH is a bit much for so little volume. You are going to be better off with spectrum selection and intensity by using a fluorescent style of lamps; NO, PC, or VHO.> 2) Hang-over-the-back Penguin Bio-wheel filter 3) Penguin 155 gph powerhead 4) 5" heater 5) 1 X 15w 18" 10000K strip lights 5) 25 lbs. Fiji LR 6) 2" thick LS 7) Inhabitants: 1 spotted hawk (2"), 1 green open brain coral, 1 colony of brown button polyps, 1 Astrea, 3 Turbos. I am very slowly and carefully adding livestock to the tank. I intend to build a reef tank, hence the question about lighting. Please advise and thank you in advance. <IMO, you are going to be better of with 4-20 watt NO's or 2-55 watt PC's. Much cheaper, easier to get replacement lamps, better selection of color temperatures, etc.> Best, Mimie <Have a nice day! -Steven Pro>

Re: Affordable Metal Halide lamps and some questions Dear Steven Pro, Thanks for the prompt reply. Could you please point me to an online dealer with reasonable pricing on 2 X 55 watt PC retrofits. <I would definitely compare prices, but do check: www.AHSupply.com and www.ChampionLighting.com> My fluorescent housing is approx 21" in length and is removable without having to remove the hood. Thanks in advance. Best, Mimie <Have a nice day. -Steven Pro>

MH Lighting Hi, I am planning on upgrading my tank size from a 55 to a 120 (48x24x24). I currently have about 15-20 frags of SPS and assorted LPS. I am stuck with the decision between 2-250 watt 6,700K Iwasakis w/ 4-96 watt actinics or 2-250 watt 10,000K lighting with actinics. Can you make a recommendation on which combination you think will be more effective in maintaining colors in the SPS while having a crisp non yellow coloration. <Really, with actinics, either should be fine.> Can you also make a recommendation the best ballast for Iwasakis and the MH I am interested in, and the best manufacturer of 10k bulbs. <Please see here http://www.WetWebMedia.com/marine/setup/lighting/mhmarfaqs.htm and here http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/aquarium.html> Please feel free to let me know if there should be any changes in the combination of MH and PC color temps. <Seems fine.> I would greatly appreciate any information. Thank you, David PS: If your ever in Miami, FL look up Aquariumart (my place of employment) <If we ever get down there, we will try. Thank you for the offer. -Steven Pro>

Metal Halide Hi guys, can I use a standard Hibay metal halide ballast and reflector for aquarium lighting, if so how many watts is too much, my aquarium is a 125 gallon reef and I have two 400 watt units. Thanks, jjk <I would never recommend to for most any aquarium, although I favor MH lighting. 400 watts is an obscene and potentially dangerous amount of light for aquaria less than 30" and for anything there except for some SPS and clams. A few hardcore aquarists have lucked out with these lights but most aquarists struggle with stressed animals under these lamps. Even 250 watts if too much for most systems. There have been some complaints too about the industrial fixtures exploding some aquarium designer lamps or not firing them at all. Despite all of this, the light you pick ultimately depends on the livestock selection. You must pick your intended corals before you know how to light them! I personally wouldn't take this fixture for free... too many hassles. If your tank is simply 24-30" deep and you want good lighting... buy a 175 watt 10K Aqualine MH lamp for every 2 feet of aquarium length. You need no other bulbs/actinics, etc. Best regards, Anthony>

Lighting choices - 07/09/03 Hello there, <Hi Sam, PF with you here tonight> I'm not sure who this will be routed to, but here goes: I have a 75g reef w/ dual 175w 5,500k MHs.  Now, I'd like to replace the generic 5,500k bulbs that came w/ the canopy, and I'm wondering what to use.  I'm thinking 10,000k Aqualine or 20,000 XM.  I know color is sort of a personal preference, but coral-health-wise, what would you recommend for my setup?  I have star polyps, leathers, Montipora, frogspawn, elegance, mushrooms, and fox coral.  Note: (someone on the Reef Central forum mentioned that his greenish coral die off when he uses 10,000k MHs....unique experience I hope).  <Never heard of a die off before. I'd say go with the 10K's.> But, my question doesn't end there.  Since I have no room for another canopy, I'm going to install another set of lights in my MH hood.  I'm leaning towards dual 55w PC actinics to compliment the MHs, but what would you do?  I'm really interested in your opinion.  I know there are few right-or-wrong issues in this hobby, so I'm looking for the advice of someone with experience.  All I'm looking for is healthy coral and decent-looking light for my own visual benefit.  Should I be using 10,000k MH w/ dual 55w PC actinic, or 12,000k MH w/ regular 55w PCs, or 20,000 XM w/ regular 55w actinics? The combinations are overwhelming.  I will be eagerly awaiting your reply.  Thanks!  Sam Sundberg  <Well, actually I'd advise using VHO's, generally they're regarded as the best choice if you're adding actinics.  This is just my $0.02, there's as many opinions on lighting as there are reef keepers, but the consensus is the 10K's and the VHO's. Hope that helps, PF>

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