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FAQs about Metal Halide Lights and Lighting for Marine Systems 1

Related FAQs: 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 Lamp Issues, 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,

Throwing Some Light on Lighting... Hello there crew, <Hi there! Scott F. at your service!> Thank you guys for all the valuable info you've given me!   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).  I've more or less decided on dual 250w 10k Ushios but can't discern what is the big difference between the regular socket type bulbs and double ended HQI bulbs.  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). Sincerely,   Chris  AKA  ~ fishtank ~ <Well, Chris, there are many schools of thought on this topic. Some studies have indicated that double-ended (HQI) bulbs do yield higher par values than some comparable mogul bulbs. I tend to favor the HQI bulbs because they are also more efficient from a power/performance aspect. Double-ended bulbs do need to be run on electronic ballasts, of course, and they need to be kept in enclosed pendants (like PFO, Sunlight Supply, Aqualine, Giesemann and others offer). They are more expensive than mogul bulbs, in most cases. If it were me, I'd go with the 250 watt double-ended Ushio or Aqualine bulbs in a quality pendant-ballast combo. Some people tend to think that the Ushio and Aqualine 10ks are too "yellow" if run "unsupplemented" (i.e.; without VHO actinics). Some of the newer bulbs that are proving popular from both an aesthetic and performance standpoint are the 14k and 14.5k bulbs offered by companies like Giesemann, Hamilton, and Aqua Connect. The AC's are not cheap, but they are beautiful from an aesthetic standpoint. Good luck! Regards, Scott F.>   

Lighting Opinion  11/16/05 Hello All, Just a quick question, I have just upgraded my lights to (2) 25 <Likely 250> Watt HQI Retro kit from CA over a 4ft. 100 gallon tank 2 ft deep. I raised my canopy so the lights are about 10" above the water and have installed fans that keep my water temp. and canopy at or around 79 degrees. The light appears to be a lot brighter but I think it looks nice I went with 15,000k CA bulbs as the 10,000k were just a little too yellow for me. Is this too much light? I have the following: Ricordea (mid bottom of tank) Flower Pot (bottom of tank) Pulsing Xenia (all over) button polyps (top) 140 lbs of assorted live rock 3 inch live substrate Thanks, Paul <Should be fine... I do hope/take it the change was done, is being done over a number of weeks. Please read here re: http://www.wetwebmedia.com/acclimcoralslight.htm.  Bob Fenner> 

MH lights and coral growth 4/14/05 Dear Anthony <Cheers> I am upgrading to 250 watt halides (Arcadia series 3). These are going pride of place over my 130 gallon mixed reef garden setup. I have the following corals 1 Montipora 1 frogspawn 1 Euphylliid (hammer) 1 Montipora 1 Turbinaria several Caulastrea colonies 1 sun coral 1 Pavona various Sarcophytons <Hmmm... overall a moderate (light) needs tank. It will be good/better if the 250 watt lamps you use are 10k - 20k K in color> All are placed away from each other and at heights specific for the genus, allelopathy is reduced by regular weekly water changes and regular preening of the softies. My existing light setup is 5 60 watt VHO lights and 1 T5. My question is really what should I limit the halide photoperiod to? <6-8 hours will be fine here for MH> Water quality is fair and I get fabulous growth from the Pavonas and frogspawn and Euphylliid. Not so much growth from the SPS hence the reason for the halide upgrade. <Hmmm... you are a bit mistaken here, perhaps. Water flow (increase) and feeding (try DTs Natural Diet for your SPS corals) are much greater influences on coral growth. Increasing light alone will not improve growth in many cases> My wattage is essentially doubling so I know I have to go gentle with the adjustment. <For this gentle acclimation, do a key word/phrase search for "screen method" here in our WWM archives :) kindly, Anthony> 

Acclimating to Metal Halides Hi, Love WetWeb but I am little confused as to how I should acclimate a new lighting system. I currently have a 75gal with mostly LPS and soft corals. I am currently running 4 65watt pc lights with one 18k standard fluorescent. I have noticed that the deeper I place corals the worse their health gets. I read over and over lighting requirements for this size tank and I really think the best way to go is Metal Halide especially if I want to experiment with SPS corals. I am looking at getting 2 175 watt 20K metal halides and I am going to run these with my 4 pc lights all actinic. What is the best way to introduce these new metal halides? I was going to start high (about 20" of the water surface) and gradually lower. But then I read that you can start with 1 hour of light for the first day and increase this by 30 minutes every day until you reach the desired cycle time. Which one do I use I am confused. Thanks.....<Terry, either way is OK.  James (Salty Dog)> 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>

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

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>

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>

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>

Acrylic Tanks and MH Lighting We are in the investigating process of the "big tank" (650 gal). We want to leave the top open and use metal halide pendants for lighting since everything except the viewing window will be behind the wall. In one of the quotes for a custom tank the dealer said the tank has to be glass because the metal halides will destroy an acrylic tank. I have never heard this before and we had really decided that acrylic was the way we wanted to go. Is there any truth to this? Thanks in advance for your help and for the MANY questions that will be coming your way in the next few months. Beckie <No truth to it as far as I'm aware... Our old companies installed hundreds of acrylic tanks with metal halide lights in them... Bob Fenner>

Acrylic Tanks & MH Saw the post below about MH and acrylic tanks. Just wanted to add that most acrylic tanks leave a considerable amount of acrylic in the top pane for structural support. A MH placed directly over one of these acrylic struts will likely cause that to crack. <Ahh, yes... Needs to be offset, and even then, suspended per manufacturer's recommendation... per wattage, a good distance above the top> But as long as the bulb is over a cut-out it should be fine. (I'm speaking from personal experience: I cracked one of my struts with a misplaced MH bulb. Others have traded thin acrylic panes on standoffs as heat shields; not sure if this works.) <Me neither. Likely not absolutely> A professional acrylic aquarium craftsman also warned me that the normal practice of polishing the top pane in order to round the edges of the cutouts can result in "crazing": a network of fine surface cracks that can, over time, develop into a real problem. MH bulbs might make any potential crazing worse. He bevels his edges rather than polishes them to reduce the risk of crazing. <Good input. Thank you, Bob Fenner> Marc

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>

Re: 175W v 250W Thanks for the advice, very helpful. Think I'll go with the 175's. <<Greetings, hopefully I can continue the helpfulness trend...>> This aquarium will be dead center in the middle of my house with no easy access to exterior walls, nor do I have access to the attic. Therefore, I am concerned about proper ventilation and the need for a chiller. We are looking at possible temps tomorrow of around 110?F (unusual, but not by much for July & August in Fresno, CA) that means I may see 80?F indoors. As this is already at the limit for aquarium temp, I assume that there is no way that I can add any heat from lights or anything else without running a chiller. <<is a go assumption, yes.>> I had planned on putting all the hardware, including ballasts, in a closet that shares a wall with the aquarium niche. I don't think that there will be a problem with heat from pumps, etc., but how about if I add a chiller? <<That would definitely be a problem.>> Does a chiller of appropriate size for this system generate too much heat to be confined in a 4'X6'X7' space without active ventilation? <<Oh for certain...>> If I exhaust the air from the hood and the closet into the interior of the house, will I be sorry and wished that I found a way to exhaust it outside instead? <<I would think so, yes.>> I can run a duct to an exterior wall but it would not be a small project. If I do run a duct outside and install an exhaust fan ((150CFM split between hood and closet), would there be any need for muffin fans? <<They certainly wouldn't hurt.>> I know its hard to be specific when you don't know the exact layout, but I am just trying to get an overall feel for how much heat is generated by a complete system and whether or not the interior of my house can handle it (2,000ft2 downstairs where aquarium will be and 1,000ft2 upstairs, lots of ceiling fans). Regards, George Nikolich <<Cheers, J -- >>

MH Lighting On my 180 All-Glass reef tank I have 3-250 watt Iwasaki MH lamps with PFO ballasts. From bottom of the lamps to the water 7", from the top of the water down to SPS corals 12", then down to the sand bottom a another 12". Sanjay Joshi's 180 gallon All-Glass reef tank changed the lamps from 250 watts to 400 watts to try a different spectrum. I asked PFO lighting who said not to do this on a 180 gallon tank like I have. In 2001, Sanjay Joshi change to a more open tank like I have. What is right 250 or 400 watt Iwasaki lamps? RGibson <If you are getting good growth and color and are using high quality lamps, I would not upgrade to 400 watt fixtures. -Steven Pro>

175W v 250W halides Have enjoyed reading all FAQ's but still looking for the definitive answer to my question. I am doing a custom 68X24X24 installation in my home and have been debating whether or not to go with three 175W or three 250W MH bulbs with or without VHO Actinics.  <rest assured.. an easy question> I am new to reef aquariums, but my goal is to reproduce a shallow Indo-Pacific reef with lots of SPS corals. I'm sure that I will start with less finicky species but I want a system that maximizes flexibility and will have plenty of capacity for more demanding species later.  <even still... you probably do not need the 250 watt bulbs. The tank is shallow enough and the beginnings with less demanding species may be very difficult with 250 unless the tank is hardcore SPS and clams (few or no Corallimorphs, zoanthids, LPS and the like)> The tank will be placed in a wall niche and there is a 3' space overhead that can be used as sort of a very tall hood.  Halide placement will be 9-18" above water. <Around 12-16" is typical> Therefore, I can regulate light to a degree by raising and lowering individual pendants. <not recommended unless you will use a Luxmeter concurrently. Else it is dangerous guesswork with symbiotic animals.> I would also like to maximize the height of the lights to reduce heat transfer and make access a bit safer.  <the heat from a well made pendant or hood is no different for VHO than MH... they all produce heat and can be tempered by an inexpensive to buy and inexpensive to run muffin fan (8-12 watt). Really a better solution than tempering the efficacy of high dollar and useful lamps> However, I don't want to go overboard and generate extra heat and consume watts that I don't have to. <the heat issue is an overblown marketing artifact of people that sell fluorescents... you can easily get burned on VHOs just the same and MH lamps categorically give one more bang for the buck (value) than any other lighting... especially for SPS corals> Is there a good source for information on light distribution patterns for various MH reflectors? Most of the specs I have seen say that they will light a 2'X2' area but they don't say at what height. <Sanjay Joshi has done a lot of great work on this topic. Link to his work on our links page or do a keyword search of his name. Great stuff> How can one make a reasonable estimate of light loss with depth through water assuming average transmission properties (if there is such a thing) for a well kept, low organics reef aquarium. <Luxmeter is a very useful tool to illuminate the efficacy of MH over fluorescent. Also, add VHOs only for any aesthetic preference that you might have. They are not needed otherwise. Good metal halide lamps have enough blue spectrum. Go for Iwasaki 6500K, Aqualine or Ushio 10K> Best regards, George Nikolich <with kind regards, Anthony>

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>

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>

MH lights: mounting distance Hi! Bob, <Anthony Calfo in your service> I have a question about mounting metal halide lights on top of aquariums. I have a 250W and 400W on top of a 240 gal acrylic tank.  <I assume that you have a tank full of SPS coral else you have way too much light. Of course, you may instead be trying to make lava...Hmmmm?> The halides are only 4" above the tank which is covered by glass.  <OK... making lava it is...> Yesterday the glass broke and the top of a acrylic has a major crack in it. I assume the region is getting too hot. <that would be correct, and an understatement my friend> Questions: How far above the water level do you recommend for the halides? <9-16" depending on the invertebrates needs and lamp intensity. You will likely want to be 12-16" off the surface of the water> Does the tank need to be covered and if not will the water evaporate and cause scaling on the bulb? The tank should have some kind of guard at least to prevent jumping fish. This could simply be a plastic light diffuser for drop ceilings (AKA egg crate). And the lamps separately may/will need some sort of UV lens. The topic is debatable regarding it's impact on coral pigmentation. But the closer you are to the water, the more you will need that lens for several reasons... not the least of which is the hot bulb shattering if cool water should be splashed upon it. Do check out the following link for further reading: http://www.reefs.org/library/talklog/s_tyree_060202.html > Thank you. <best regards, Anthony Calfo>

Lighting a 180g Tank Guys, I wrote about a month ago about lighting my 180g tank. Bob encouraged me to look into halide lighting for hard corals and tridacnids. After much reading and talking with lighting guru's, most recommendations point to the use of double ended (HQI) bulbs powered by electronic ballasts. There were many claims that the double ended bulbs are much more intense per watt than traditional, single ended bulbs. I have not found any articles out there, that have done any technical test to prove that claim. <Take a look at the articles written by Sanjay Joshi, a professor Penn State. His website is here with links to several of his works http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/aquarium.html> If any, what are the benefits of double ended bulbs. Would you consider 3 250W @ 10000K (with actinics) be sufficient for the more demanding hard corals and tridacnids? <Sounds like more than enough.> It is also my understanding that double ended bulbs do not have a U.V filtering, outside envelope. <Correct> In a DIY project, how would one come by UV filters. <See if Sanjay mentions it in his piece. Most units I have seen come with the filter built in.> Thanks again for many answered questions. I'd give away my mom's Chitins 'n' Hot Sauce recipe to be able to get the reef lighting right the first time around...JS <Have a nice weekend. -Steven Pro>

Halide Lighting Distance Hello, Just wondering about the basis for the suggested minimum distance from the water surface for MH lighting. <Six inches is as close as I would get.> I have just bought a nice AB dual setup but find the spread of the fitting means a lot of spill from the edges unless it is quite close to the tank surface. While the recommendation varies from 20 inches to 10 inches (min.), can you tell me if this is because of potential heat loading or UV emission or something else? <The closer you get the greater the risk of substantial heat transfer and water splashing and shattering the lamp. Also, when you lower the lamp you increase the light intensity, so you must do this slowly. The UV should be taken care of by the shield, either built into the lamp or fixture.> Best regards, Jordon Peters <Have a nice day. -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>

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>

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>

Too Much Shimmering! Hello Gentlemen, I just installed my 2 x 175 watt metal halide with spider reflectors and it is working fine except it is shimmering too much. It is to a point where I almost get dizzy looking into my tank. Is there any way to decrease the amount of shimmering effect? <Not really. Most people consider it a benefit of MH's.> Is this cause by the nature of the reflector or because I have so much water movement on top? <The shimmering is caused by the ripples on the surface of your water. I would not change anything now and see if you do not get used to the new effect.> As always, thank you very much for you input. Cheers, Dan <You are welcome. -Steven Pro>

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>

Water Quality, Air Bubbles and MH lights on too long Hi Bob, <Anthony Calfo in your service> Seems to me that water hardness in a marine aquarium should be high.  <yes...relatively speaking> I didn't realize this at first and was shocked that the water was way off the scale on GH and KH. Is there a point at which this is too high? <11-12 dKH is very fine...approaching 18-20 is scary if you have a reef and you are dosing calcium for fear of a crystalline precipitation> Secondly, I've got a 65 gal tank with 30lbs of live rock, 1" of large crushed coral,  <thin this out if you don't siphon it frequently> some snails, shrimp, and crabs. Its been up for 3 months not doing much. I've had a sump connected, but removed it due to gear problems. I've got this annoying bubble problem. First I thought it was the sump, and to some degree it was, but now all I have is a power head that is submerged 10" from the surface and a heater and there are still bubbles.  <sticking to and emanating from the rockscape? If so... lights may be too bright or on too long> I thought it might be the water quality (see above), <no way> but I've done some large water changes (30% x 2 in 2wks). Everything else water quality wise is good. The only other problem that I seem to have is algae. This started when I put on the Metal Halides over the aquarium.  <hello! There's your answer. MH bulbs closer than 12" (not necessarily bad) or on for more than 9 hours daily (more likely and possibly unnecessary) are often culprits> This in tandem with the addition of some tap water and pure circulation and no protein skimmer.  <Aiee! you're killing me. No skimmer?!? Why don't you just cut one of my fingers off instead...hehe. You will continue to have serious algae problems in all likelihood without a good and functioning skimmer> I've got the skimmer now (EV-120) and waiting for the pump.  <nice unit> I've purchased a 5 stage water RO/DI Unit which should be the cat's meow.  <agreed> I've also purchased a great sump return pump. When it all get here I start up the sump again. <sounds like it will be a nice setup...have faith and patience for it to come together> Any ideas why I've got so many bubbles? Puzzled? <no doubt in my mind that you have your lights on too long... I've seen this with hundreds of aquarists in the past decade. Kind regards, Anthony Calfo>

Making Lava Hi again! <greetings Walter, Anthony Calfo here for Bob... either my meds are wearing off or this is the first time that I've had the pleasure to answer a query from you> My tank size is 48w 24h 30deep, I have 2 400watt 20,000k metal halides and 4 VHO 660 Ice cap fluorescents 2 50/50 2 actinic. <good Lord that's a lot of light! Unless you are making lava in your tank, I'm hoping you are going to tell me that you only keep shallow water SPS corals, because I can't see another reason for 2(!) 400 watt halides on a 30" deep tank. Of course, the other possibility is that you were the victim of a convincing light salesman> My question is ....... I was wondering if it would affect my corals and fish @ all if I had the halides go off and on Twice a day, I currently have them go on 1 hour and a half after the icecaps go on, and they go off 1 1/2 hours before the actinics do. The halides are on for @ least 9 to 10 hours a day. <although hardly natural... I'm sure the fish would adapt. And the corals would stop screaming for a couple of hours. Indeed, 9-10 hours is a bit too long for halides over most systems. All joking aside.. if you've had your system running like this with coral for more than a year, have you noticed a tendency for pigmentation of many coral species to shift to yellow or a like pale color?> I think I would set them to come on for 3 hours and off for 2 and then back on for 4 hours. What do you think??? <it sounds like a better scenario than present. kindly, Anthony>

Go Steelers! Thanks for all answers! I hope your Steelers will win the championship. Go Steelers ! (In Latvian: Uz priekshu, Stiileri!) Maris <Maris, you are very kind! Thank you... best regards, Anthony>

400 Watt Metal Halides hi there thanks for the response No I am not making lava, Ha HA! And I am not the victim of a clever sales man either.  <Walter, I thank you kindly for your sense of humor!> I had my tank running for about a month now. I have Red sea xenia which has gone bonkers with the open close open close rhythm, <unrelated to lighting...definitely a dynamic of fluctuating pH/alkalinity. I have cloned more than 10K frags of Xenia in my greenhouse in the past decade and found this to be one of the few truisms of reef aquariology> small Acropora frag. that seems to be doing fine  <indeed...better suited to the lighting> a couple of leather corals ( yellow ) A green lobo. piece small <the Lobophyllia will not survive long under these lights...six months to a year max if direct. Do try to shade or filter light with an outcropping> one huge Sinularia one small green finger coral 2 colts one may have be affected by the light, <almost certainly... Colt Corals (Alcyonium) are deeper/turbid water> green Starpolyps about half way in the tank and a green tip torch coral fully open.  <same as Lobophyllia> What can I do to maybe lessen the amount of light so my corals don't get hurt in the future  <do not play with photo period or cycle so much... better to leave on 4-7 hours daily, but screen the canopy with a filtering mesh or like product to reduce but not block all light (like plastic fly screen). You can add layers to get the desired effect> or maybe other thing I may put in there Like clams,, Acropora etc....... Any suggestions from a pro??? <now you are talking, bud... when life hands you lemons, you make lemonade! Clams (Blue maxima and crocea in particular) and shallow water SPS corals would be the ticket. Avoid most all brown pigmented corals (tend to be deeper water). Good coral choices for bright aquaria include Pink/Orange Montipora, Yellow Finger Porites, Goniastrea closed brain corals, Yellow Leathers and colored Porites. Study photographs in Veron's works of shallow/tidal corals and research the availability of ones that attract you. Best of luck to you, Anthony Calfo>

Lighting Shade DIY Thank you, Where would I get this plastic fly screen??? Is it the stuff you use one screen door and windows?? hey thanks for your help. I greatly appreciate it and so do my animals!!! <Yes, You can get this product at Home Depots and other such places. Do be sure to get the, I believe it is called, "vinyl" screen. Sometimes there are copper and aluminum mesh available, very bad for reef tanks. -Steven Pro>

Lighting Follow up ok I went to home depot and saw all the screen things. I bought one that said that it was Made of thick strong Vinyl coated polyester it is supposed to be able to handle it when a dog jumps on your screen door, I hope that was it. <Sounds right.> well I put it on top of my tank and made some holes in it so that some of the strong light hits the Acropora (2 pieces 1 frag and a new addition) The tank is not as blinding as it was I guess I will have to observe the animals and there reactions, I just wonder how much light is getting in I have a small doubt that it may not be enough but I know I am a fraidy cat, what should I be looking for in the coming days if something may go wrong? <You may notice a change over the next month or so. Probably for the better. I think you will see better polyp extension on your LPS's and better colors on your SPS's.> You know when I bought the lights I was thinking to buy the 250 watt halides, but I thought more would be better so I bought the 400 with the 660 Ice caps. Well I guess I goofed it up, If I ever want to simulate the earth getting closer to the sun or maybe the planet mercury In my tank I could use my lights!! HAHAHAHA! <Do not feel too bad. It has been a trend in the hobby that is just beginning to reverse itself. -Steven Pro> Thank you!!

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 (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>

Cooling Fans Hi Bob, I have a mechanical question for you. I am embarking on adding MHs to my hood, and I know the heat will rise considerably. I plan on adding (for starters) one fan to the hood. If need be, I will add a second. <Good idea... one in/out> I was going to ask what I thought would be a stupid question: Should the fan pull room temp air into the hood, or should it force hot air out of the hood? I searched all of the FAQs on the site, and I found where you recommended two fans in hoods -- one pulling in, and one pushing out. So . . . I guess it's not a stupid question. With that, what should I set my initial fan to do -- pull in or push out? <Out my friend> If I get to the point that I need a second fan, are you still of the mindset of having one pull in and the other push out? <Yes> Many thanks! Dale. <Bob Fenner>

Light ? Hi, I was wondering if you have any experience with the custom sea life prism pendant (175w MH / 2 32w CF)? <A little> I have a 65 gallon tall tank (34x18x24) and I was wondering if this would be enough light to keep anemones and corals like the bubble coral?  <Should be, yes> I currently have the tank set up with a 110w CF with some leather corals and mushrooms and I don't have much room in the canopy for any more CF's. Thank you, Trevor <Make it known how your conversion comes out. Bob Fenner>

HQI lighting I've been reading a lot about HQI lighting and would like to have your opinion on them. Are they lights that would need a lot of equipment to cool the tank? <Aka metal halides... do produce prodigious amounts of useful photonic energy... but as you state with concurrent high energy use, heat production. Please read over the many sections on light, lighting and associated FAQs posted on our site: www.WetWebMedia.com in many sections... starting here for Marine: http://WetWebMedia.Com/lighting1MAR.htm 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 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>

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 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>

175 MH I just finish reading most of you questions and answers on your FAQ section and am very impressed. Maybe you could help me also I hope. <I will try> I have a 75 gallon tank 4 foot by 1 and a half by 3 deep. <Three feet! You must have long arms> And over it I had some hardware store bought MH 175 each Someone told me that those lights were too yellow and so I went and bought some Sunbursts 10k 175x2. Well not only does the tank look purple but a little dark the soft corals went into shock and algae growth was very bad <Hmm, a bunch to state here... 175 watt metal halides are not powerful enough to adequately light three feet of depth of water... If you can otherwise deal with the waste heat, I would look into 250 or even 400 watt units... two fixtures. Temperature is important, as is the brand/maker of the lamps... there are less blue varieties in the 10,000 K range... You need to graduate new lighting changes to your livestock... with timers, shading of new lamps...> Button corals were not doing well and well it looked like a disaster. So I gave in and put the old bulbs back in and it seems that everything is calming down. My question, what lights should I put my money into? I'm confused. I have a couple of fish and some live rock and some soft coral what do I do now? <Please post your "what type MH" question on our Chatforum: http://talk.wetwebfotos.com/ The many fine folks there are more up to date on what's available. Be chatting my friend. 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>

Metal halide lighting good morning, evening... <Or afternoon> if you find some time...could you give me some info on the following... we are upgrading our system and need to get a new metal halide unit to successfully keep clams and hard corals such as Acropora. our new tank will be 5ft long by 22 inches high and 18 back to front. our present unit is a system 2000 double 150w with 2 actinics. I believe it was a mistake, too little light. <Yes... you could easily use two, three times this amount of illumination> So, as I am in UK, all what I have come by are Arcadia and system 2000 units. I've also been informed that apparently the double 250w arcadia light overheats and since causes the unit to melt? <Yikes. Poor engineering... what does the company say to this?> what other brand would you recommend, and if not in the UK, is it possible to order it from the States? or anywhere else in Europe? <Do contact the folks at Tropic Marine Centre there (the link/URL is on our site www.WetWebMedia.com links pages, and ask their input please> let me know what is best. as always a BIG thank you from Stefi in London. <You're certainly welcome luv. Cheers, Bob Fenner>

Cloudy Water Orangetailblenny here bugging you again. (sandy) I read up on the material you suggested, and as much as I want a clown trigger I guess not. I'm real dumb on this lighting thing for the wet pets . Soooooo would you talk to me like a 4 year-old on the light my fish need in a 55 gal. cube shape (square) tank about 1 yd. deep? (Yikes... a meter-yard deep? Probably a pendant or two of Metal Halide... Please read over the Marine Lighting, and Light sections on the www.WetWebMedia.com site... the sections are simple enough that even I understand them...!) I gotta tell you bob:::::::you do every thing I dreamed about doing when I was young. my hero + john Wayne. ha :::::::::::::::::::ta and see you in the sea-lol:::::sandy (Hmm, wish you were here (visiting in Baja's end the last few days)... cold, surgy, not so fun for diving, pix... but manana is another day. Bob "Duke" 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>

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 lighting Robert I currently have a 110 gal fish only tank with 1x48in 50/50 florescent, that I would like to turn into a reef tank (i.e. live rock, corals etc). I have a 400 watt metal halide lamp that I am planning on adding when I make the switch over. I will be using a fan to dissipate heat from the tank and I have about a dozen snails to take care of at least of some of the microalgae plus I have recently added a refugium (built out of a 5 gal bucket). What other factors might I have to worry about when adding this dramatic increase in light, and possible remedies?...Thank You.... Nick <Very good question... and a shame you don't have two 175 watt units instead... very hard to get much spread over the size, shape of this system with a single pendant. By increasing photosynthetic rate via increased light intensity, you need to concomitantly elevate alkalinity and biomineral content (or do what needs to be to keep elevated...), guard more critically against pH swings... likely add Carbon Dioxide in some fashion... be more diligent, regular about testing, supplementing, cleaning in general... More specifics as your system develops and the situations arise. Bob Fenner>

What Size/Wattage of MHs? Hello Hope you can steer me in the right direction. I am going to purchase another lighting system for my tank(48x24x24.The lighting I currently have now is the 4 96wattpc"s. When I purchased these last year , they said I would be able to keep SPS corals as well as clams with no problem. As I am finding out you can't. The watts per gal. is only 3.2.  <And the tank quite deep for CF lighting use...> Needless to day I am not happy , so I am going to purchase a halide , actinic system. custom SeaLife). I am a little confused about the bulb wattage though. Some folk's say that I could use 2 175watt halides and be able to have all the maximas and Croceas my heart desires with no problem. On the other hand , I am told to purchase the 250ewatt halides because my tank is 24inches deep. Can you please clear this up for me? <The 175's would work, but the 250's would be better... there are even people who would encourage 400 watters... and I've used 1kilowatt fixtures on two foot deep culture units... The balance of waste heat production, electrical consumption, driving photosynthesis, algae problems, matching biomineral, alkalinity, CO2... All have to be figured in, dealt with> I am hoping to purchase the proper lighting (this time) , and don't want to screw it up ,as you know these halide systems are very expensive. The set up I want is a little shy of $ 1000.00.Hope you can help me with this , because I can't afford to do this AGAIN. As always thanks, and take care. PS. I can't wait for your new books! <Me neither... and do go with the 250's... IMO these are the best choice for you, for the organisms you want to keep, what you want to do with them, and how much trouble you're likely to cause yourself. Bob Fenner>

What Size Metal Halides? Hi Bob Hope you are having a fine day today. I have a question on lighting. My tank is a 120gal the size is 48Lx24Hx24W. My present lighting is the 4 96watt pc's. I am going to purchase a halide set up so I can have a few SPS corals along with a few maxima clams. As for the dimensions for my tank should I get the two 175watt halides or the two 250watt halides ? I will also have the proper actinics added. once again, thanks for your time, take care. <If it were me, my system, I'd go with the two 175 watters... some folks would opt for the higher wattage ones for sure, but they're unnecessary, will elevate your tank temperature and electric bills too much...  Bob Fenner>

Boring lighting questions Bob, Sorry to keep bothering you with banal lighting questions-but I value your opinion a great deal!  <Glad to help> Alright, contrary to my previous metal halide stance, I have this question. Will a 250 Watt MH pendant (the hanging one in the bell shaped pendant) work for my 40 standard acrylic tank. It is 36 inches long and about 16 inches wide, and 18 or so inches deep. Thanks a lot for the help. -Josh <Yes, a likely choice... perhaps a bit low intensity on the "edges of the tank... but a nice choice, good appearance... Would cost about forty dollars a month to run electricity-wise in California currently! Bob Fenner>

MH lighting vs. PC lighting Bob, I have just finished reading the articles on lighting posted on your website. I still have a couple of questions relative to this subject. I have a 300 gallon fish/invert system. The tank measures 96x24x24.  <This is more a 240... a stock shape system in the trade... about 231 cubic inches per gallon...> I am currently using 2-400watt MH and 2-175W MH bulbs to provide lighting for the fish, leather corals, mushrooms, polyps, anemones, and some LPS corals. Of course I have the usual problems of excessive heat, and ultra high utility bills. <I do understand this!> Could I successfully convert my lighting to PC's and still have my animals thrive?  <Yes, in all cases... even if you have high-intensity light species like tridacnids, many SPS corals, they will do fine, some better under CF lighting... in a twenty or so inch depth of water system> Would it save me on my utilities and heat gain?  <Absolutely, on both counts> And is there a table or matrix available to determine how many PC's and what size (wattage) they should be? <Maybe somewhere... haven't looked for recently... Take a look at the links to lighting manufacturers on the www.WetWebMedia.com site> Thanks for your input. Bob McCook <You're certainly welcome. Bob Fenner>

Lighting Hey, I want to convert my fish and live rock tank to a fish and invert. tank. I am going to buy a wet dry filter and put my existing protein skimmer, heater, and UV sterilizer in the sump that is attached to it. I plan to buy 50 more lbs of live rock (to make a total of 85lbs) and get rid of my coral loving butterflies. My main problem is lighting. I plan to keep clams, algae, and maybe some soft corals. I have a 54 gallon corner tank with 40 watts of lighting. The problem I have with power compacts is that I can only fit in a 24 inch long fixture. So if I got a power compact like the one from all-glass it would only add 15 watts more of lighting. I am pretty sure that would not be enough lighting. What do you think would be the right amount of lighting? <For the mix of life you list, size, shape of tank... about 150-200 watts... and this is possible with retrofit kits and some clever installing... do look at the parts for sale here and there on the net... FFExpress.com, the many good company's listed in the hobby magazines like FAMA> So I am left to VHO and metal halides. I have read about two kinds the normal and some sort of mercury filled kind which seams to be more economical as far as replacement bulbs go. I figure a 175 watt or 250 watt bulb would be enough light. The VHO lights would put me at 150 watts with 2 bulbs in a 24 inch fixture. Please send me your recommendations on what you would use in my dilemma. <Dilemma? This is a tremendous opportunity for growth Jonathan!> Thank you, Jonathan Pac <A metal halide along with some actinic power compacts could work here, and be very attractive... and yes to seeking out cost savings... Do make provision for alleviating waste heat problems... Likely having a splash tray arrangement with your sump/wet-dry, maybe with added air (from an air pump) and steady/daily make-up for evaporation will do. Bob Fenner>

MH Fixture Placement Hi bob, I just emailed you and forgot to ask 1 thing...I told you I have a 55 gallon high tank, so its not as wide as a normal 55 gallon but higher. I was thinking about getting a metal halide instead of the additional 2 55watt pc, but the tank has that strip of plastic down the middle, which is where I would have to hang the metal halide above, directly in the middle, in this situation, I thought that too much light might be blocked, am I correct in assuming this?...would the metal halide combined with the 2 55 watt pc I have now be that much better than just adding another set of 2 55 watt pc?...sorry for emailing you twice.. and thanks again....Jeff >> You could place the MH or two off to the side(s)... no need to completely illuminate the whole system the same... functionally or aesthetically... Bob Fenner

Lighting - VHO vs. MH Hi Bob,  We currently have a fish only 110 gallon system. The tank is 30" tall x 48" long and I am interested in improving the lighting of the tank. Although, changing the lighting is not required for fish, we are considering going into corals in the future. Currently, the tank is lit with (2) 40 watt fluorescent bulbs. What is your opinion of a (4) 96 watt bulb VHO system versus (2) MH bulbs at 175 watts each.  <The VHO is better all the way around... Compact Fluorescents would even top the VHOs...> What do you think the economics will be for running the four VHO tubes versus the two MH bulbs. <Cheaper to run in the long haul by far... likely no need for a chiller...> Using only the MH bulbs, will the full required color spectrum be available or must this system be supplemented with other fluorescent lights? <Better to supply some actinics via fluorescent> Thank you for taking the time to answer my questions. Jim H. >> <You're welcome, Bob Fenner>

I have two questions Bob. First, would 6.0 watts be to much light over a 29 gallon tank; I would plan on using 1 Coralife 175 watt 20,000 K metal halide bulb only over this mini reef setup? My last is could you recommend some easy corals to keep in my reef tank. I have about 3.0 watts of light. Thanks for the help. Adam P. >> A curious question (at least to this feeble human)... six watts "per gallon" you mean? No not too much, many. Easy corals... see the many articles, input on the stinging celled animals posted at www.WetWebMedia.com for much more... but of what folks call "corals" the zoanthids, mushrooms, some soft corals (leathers, pulsing), "polyps" and of the stony/true corals some of the Faviids/brain corals, and Euphyllias would be my first choices. Bob Fenner

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 Lighting Bob, First, I need to thank you, as my tank has flourished under your sage advice. I've progressed from a FOWLR to a true reef tank with anemones and soft coral.  I've just recently added a sump (what a great addition, it took my UV filter, temp monitor, and thermometer out of site!) and a 175W metal halide fixture and ballast. My LFS is still awaiting a shipment of metal halide bulbs.  My question to you is this. I went to home depot where they have in stock 175 watt metal halide bulb (the Philips lighting co). There is no specification as to Kelvin. I was wondering what the difference is between this bulb and those sold at FFExpress or the LFS? Your input would be greatly appreciated.  PS. I have read every archive on FF express and have learned more about reef keeping than I would have ever imagined! Thanks, Jim  >> Wowzah, high praise indeed! My friends compare my cooking skills to sage-brush, but I always imagined this was different... Well onto your MH query... it may well be that the HD unit is of service. Get the "stock number" of the product and take an e-mail stroll over to Phillips website... all will be revealed... or better put, awakened to your consciousness, by your efforts. Bob Fenner


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