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FAQs about Metal Halide & Halogen Lights and Lighting for 40-200 Gallon Marine Systems 3

Related FAQs: Metal Halides for Medium-Sized Systems 1, Metal Halides for Medium-Sized Systems 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, 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,

Gorgeous but a big coral eater. An Acanthaster where they "grow up" on the reef flat.

Back in the game; lighting for a 75 reef       1/14/16
Hey Bob, we last spoke probably this time a year ago. Fiancé and I bought a house over the summer, needed the for the sharks, I mean attorneys, and had to sell my seahorses tank and fish only.
It's been 8 months, and I have been looking to get back with another tank, although on the cheaper side.
A friend of mine who I've helped with his tank over the years, nitrate issues, moving tank, changing rock out etc, has a 75 gallon tank at his office he no longer wants.
He wants to give it to me for free. He's awful with names, so he doesn't know what components it has or species it has other than "coral" and a purple tang.
I am assuming it has cheaper, off brand LEDs, which would be fine for low light stuff, but my goal is sps.
<I'd be checking (with a PAR, PUR meter).... am a cheapskate.... to see if the present LEDs would work>

I got a price on a t5/halide combo of 860 for 48 inch tank (yikes). So I found a local guy on Craigslist, who has a 48 inch Aquactinics , halide t5.
He wants 100 for it, not sure how old it is, but it works.
<Can only tell by.... testing>
Only issue I see is it has two halide bulbs, 400watts each, and it has two t5 bulbs. (Always thought you needed at least 4-6 t5 bulbs)
Is 400 overkill for a 75?
<IMO, yes; can be... will have to fight, adjust for heating>

I like the price, buy will it nuke the tank, and in your experience, how dangerous are halides in regards to fires etc?
<Can be trouble>
Thanks Bob, bob
<Welcome. Bob Fenner>
re: Back in the game       1/14/16

Thanks Bob. Just to further clarify, if I can save 700 by going with this 400 watt halide, would the only concern be heat?
<Mmm; no; not the only concern. Actually overdriving photosynthesis is more important; secondarily keeping up w/ testing/monitoring alkaline reserve, Ca, Mg.... >

I ask because the tank will be going into a finished basement, with central air, and on the hottest day this summer in August, the basement hit a high of 67.
<Mmm duo... expensive to pay to heat the air then cool it. IF it were me, mine, and I HAD to have/run MHs, I'd go w/ 250 watters.... IF it were me/mine I'd check the current fixture for utility. IF you measure 100 or more PAR or PUR at the depth you intend for SPS, I would stay/try this>
I understand the 75 is not deep, buy could I compensate by hanging the light 15 inches off the surface, as opposed to 7-8 inches?
<Helpful to some degree/s>
This light is obviously used , and is coming off an sps 90 gallon tank, which is 4 inches taller than the 75.
And just to clarify, you mentioned, "can only tell by..testing". The light def works from a electrical, mechanical standpoint (the four bulbs and fans etc)
<I meant bio. function wise; but yes>
If its more than a heat issue using this light, I will ditch it and wait for a 250 watt
to come along used. What makes the decision even tougher is the guy with the light lives 3 miles from me!
Thanks again Bob
<Welcome. B>
re: Back in the game       1/14/16

Thanks for that, makes all the sense in the world now.
I could use it, and hang it high, but your wasting heat and power and now have to subtract it with air conditioning. Never mind not being able to utilize the potential of the 400 and the stupid high electric bill.
Thanks for the explanation. I had a feeling, just needed it driven home
<Cheers, B>

MH Over 55 Gallon     2/1/12
I have a question about putting a MH pendant over my 55 gallon.
I got an awesome deal on a Current Sundial 250w DE HQI pendant that has 2 32 watt actinic power compacts as well. If I get it I will only be paying $100 for it.
My question is, I can't find another one because they are discontinued, so would this single pendant be enough over the 55 gallon?
<Mmm, should be... if you don't mind (and I certainly don't) shaded, less lit areas to either side... I'd position the light hanging several inches over oft-center... have less-light-using livestock in the nether regions either side>
Thanks in advance.
<Welcome in real time. Bob Fenner>
Re: MH Over 55 Gallon     2/1/12

Would I be able to keep higher light corals (clams, SPS, things of that sort)? Obviously not at the edges, but towards the center?
<Yes; in shallower water. B>

Lighting and Sump Confusion... MH choices and sump/circ. rdg.     1/4/12
Hello there,
I am purchasing a 150 gallon tank as an upgrade to my 75 gallon saltwater tank. The tank dimensions for the 150 gallon are 72Lx18wx30 deep. I would like a lighting system that will allow me to grow any type of coral that I decide to purchase. Currently I have 2 150 watt MH with moon and LED light combinations (2 separate 20inch units) . The tank I am buying comes with one 72 inch 150 MH light system, with no led or moon lights. Should I use the 72 inch fixture or should I use all of them together? Are actinic lights necessary with halides?
<I would, at this juncture, use all these 150 MH's together. 250's might be better for some species placed near/er the bottom, and no to needing actinics... These are mostly for looks, not function. Please read here re: http://www.wetwebmedia.com/marine/setup/lighting/actinicfaqs.htm
As for the sump, I have a 25-30 gallon sump currently with a very strong pump
<Better by far to have a not-so-strong pump here, and use internal pumps to move water about for circulation. See WWM re>
and a large protein skimmer that is plumbed outside of the sump. I would like to use this same system for the 150 gallon. Will the volume of the sump be too small and if so, what would you recommend?
<Mmm, as large a sump as possible... this one can be made to work... given sufficient number, diameter of overflows... to discount transit volume size issue... Please learn to/use the search tool/indices on WWM... For here, start reading: http://www.wetwebmedia.com/marsetupindex2.htm
the second tray down....>
I do not understand what the significance of the volume of the sump is, could you explain please?
<Is gone over and over where you've just been referred. Please feel free to write back w/ more specific concerns, questions should these not be fully realized by your reading>
Thanks so much :)
<Welcome. Bob Fenner>

Help on MH/Reef Lighting 9/21/11
Dear Crew,
Thank you, thank you, thank you! I must say again what a wealth of great information you have, thank you!
<You're welcome.>
Ok, now that I got that out, onto the topic at hand ^_^ . I have been reading through the FAQs on lighting, but I was hoping to get some confirmation if I am on track with my lighting or if you might have some suggestions on which way to go. I am planning on swapping out my two 4x 39w T5 fixtures over my 125g tank for 2x 250w MH. I don't have a lot in there right now save some mini carpet anemones and mushroom corals (a lot less now that I fragged off about 40), but I really want to start keeping more SPS,
so I ended up getting a used 2x 250w ballast with sockets for $100 from my LFS. The reason I went with the 2x250 w was simply because the tank has a center brace, instead of 2 braces on either end like I have seen some 125g tanks have. If my tank had the 2 braces, I would have went with 3x 175w, but I thought in this case having the 3 bulbs, one would be mostly blocked by the brace, thus negating much of the benefit of having the bulb there, as well as having the possibility of damaging, or warping the center brace,
which I would like to steer clear of.
I am planning on keeping the less light demanding mushrooms off to either side of the halides, and center tank, as the brace would be shielding most of the light from over head, and the sides should have less intense light, as halides are said to cover a 2'x2' area. As far as reflectors are concerned, what should I be looking at? I don't want to toast anything, but I also don't want any of the SPS I decide to keep to starve. I have access to be able to make my own parabolics, but I was thinking of getting some Reef Optix 2, as they are fairly reasonable, since I don't need sockets.
<The Reef Optix are decent reflectors.>
Perhaps I might get better reflectors down the road as money warrants, but I don't know if they would really be needed if I kept everything towards the top of the tank anyway (due to the LR formation in the tank).
<Although metal halides do produce a lot of light, there will be much light lost without the use of a reflector. You have to realize the halide lamps emit light 360 degrees.>
Actinic supplementation isn't really an option right now, so I was looking at getting a higher Kelvin bulb. Right now it seems that the 20000k bulbs are a good option, though I was thinking about possibly getting 14000k bulbs, though I can't really decide.
<The 14Ks would be a much better choice, more useful photosynthetic radiation (PUR)>
Any suggestions here? Over all, I would like to make this the last light upgrade I do for the tank, so if it sounds ok, or needs some tweaking, please let me know.
<You did not mention the length, width, and height of this system as well as how far the lamps will be from the water's surface. Would have helped me with my response.>
Thanks Crew!!!
<You're welcome. James (Salty Dog)>
Re Metal Halide Help/Reef Lighting 9/21/11

Dear Crew,
<Justin, before I get started, please reply to the original thread. It helps to know what went on and, when mail comes in, it all goes to an inbox which is sorted out by crew members.
No one would have a clue as to which crew member responded to this query.>
I do apologize on not giving all the LxWxH and distance from water surface. The tank is a 72"x18"x22". I have a 6" sand bed so, from the top of the water surface to the sand bed it is pretty close to 16".
I was planning on keeping the lights somewhere between 8"-10" off the surface of the water to allow ample room for my fans to push some air across the surface of the water to help reduce some of the heat.
<Will help and you should have pretty good light coverage at that height as well.>
As far as the comment"<Although metal halides do produce a lot of light, there will be much light lost without the use of a reflector. You have to realize the halide lamps emit light 360 degrees.>, I was planning on using a reflector off the get-go.
<Mmm, thought you made a statement as to doing away with a reflector for fear of scorching corals.>
I was wondering if the Reef Optix 2 will serve my purposes, as spending $140-$150
per reflector on Lumenarc/Lumen Max isn't an option right at this time.
<As I mentioned in the previous email, the Reef Optix is a decent reflector.>
At most the SPS will be 6"-8" under the surface of the water, so I am not really sure if I need to spend all that extra money on the reflectors, with the corals sitting in such close proximity to the lights.
<Is not that close considering the height of your lights.>
I am thinking of getting some Montipora, Pocillopora, or Porites (though proper husbandry
will see what I end up with). I am not sure on the Acropora, as the ones available at my LFS always seems to be the green variety, and I am looking for a little more color variation. My wife loves maxima clams, but I am not
sure if the lights will be intense enough on the sand bed.
<Should be fine with your tank depth, and you may have to experiment with the lighting height.>
I Hope that helps a little more.
<Yes, it did.>
Thanks again!
<You're welcome. James (Salty Dog)>

A thank you to Bob Fenner and 55 gallon lighting questions 10/4/10
Hi Bob or other WWM crew member,
<Howdy Mitch>
It is such an honor to have you answer my question. Your book *The Conscientious Marine Aquarist * was what made me want to get into this hobby five years ago and it gave me the confidence to start up my 24 gallon Nano.
I must thank you for inspiring me to get into the hobby because I now know this is what I want to do with my life and after I finish going to high school I am going to get my degree in Aquarium Science.
<Ahh! Deeply gratifying to find your life amplified, directed by my small efforts>
Your book, and wonderful website, has provided me with the answers to basically any question I have had and I have used your book so much that it is falling off its binding. This is the first time I have not been able to find an answer. I have reviewed all your Metal Halide FAQs and do not see my question asked before and I greatly apologize if it has.
I am setting up a 55 gallon aquarium (48'L, 13'W, 20'H). I plan on making it a reef, with corals ranging from mushrooms to SPS. I am going to use the Berlin Method of filtration, so I am only using an Eshopps PSK-100H protein skimmer, a 1,200 GPH power head and 50 lbs of Marcorock. I was planning on
getting two 150 watt HQI metal halide fixtures made by Odyssea. I know this brand is really low quality, but I could not afford anything better. Today I went to my LFS and the owner was willing to reduce his prices by almost 50% and sell me a:
<... not two?>
Along with one of these ballasts I am not sure which one:
He would also include a 20,000k 250 watt Radium bulb:
<Mmm, I'd use 10k lamps myself>
This set up would cost around the same as the two Odyssea lights, but I am getting high grade German equipment instead.
<The Al for the housing>
He would also sell me the same thing, only with a 400 watt Radium bulb instead of the 250 watt bulb for the same price, but he and I both thought that would be too much light. He had the same set up with the 400 watt bulb 20' above his 48' long tank and it looked fine, but it was much wider than and not as tall as my tank.
My questions are:
1. Will this lighting set up be able to light up all four feet of my tank?
<Not one fixture/lamp, no>
I have a small black plastic brace in the center of my tank; will that get in the way?
<I would NOT place the/a MH lamp over this area... best to suspend two fixtures, about equidistant over the two open areas on either side>
I know it will light up more than the width of my tank, but I am ok with that because I am getting it for such a great price.
2. How high should I suspend it over my tank?
<There are tools for such, I'd ask Sunshine supply re what they advise>
I would like to keep SPS coral at all depths if possible and I would love to keep clams on the sand bed.
3. Is there any danger to my eyesight using metal halides?
<Mmm, some... as with all light/ing sources, best not to stare directly at the lamps, reflectors when powered on>
Since the reflector does not allow a splash guard and I do not have a canopy, I will see the bulb unshielded.
<If the lamp/s themself/ves are shielded, not such a big deal... but do keep wiped clean (ONLY when off, cool) if splash is an issue>
4. Would I be able to keep the corals and clams that I want if I was to use a 48' Tek Light with four 54 watt HO T5 bulbs instead of this halide set up?
<Mmm, not really... only the upper water area... for SPS, likely not Tridacnid on the bottom>
If so, how high should I suspend it above my tank?
<See the ad you cite... they list the availability of a hanging kit>
Here is a link to the Tek
Thanks so very much,
<Welcome! Bob Fenner>

What Wattage MH? -- 02/22/10
Hi Crew,
<<Hi Tim>>
Thanks for your tireless contributions to the enlightenment of us aquarium lovers out here.
<<Is our pleasure>>
I have read through all sorts of metal halide forums and FAQs, and well'¦ to get the bottom line I really trust the opinions here above all else.
<<Thanks for the vote of confidence>>
To my question, I have a 72 gallon 'corner' bow tank. It measures 48' across, 22' wide at its widest point, and 25' deep. I have a sand bed that is ~3-5' deep (I have an engineer goby who loves to aquascape for me so the bed varies ^^).
<<A yes'¦I do love these critters for the way they keep the substrate nice and 'white''¦but not so much for the hole digging, and 'strafing' of the corals with sand>>
Lighting = two 96W compact fluorescents. The tank has soft corals in it now; xenia, green star, and clove polyps. The clove and green star are pretty much taking over the world here.
<<Very common>>
I would like to move into SPS as the tank has been up nearly two years and doing well.
<<Okay'¦but I do suggest you at least thin out the noxious organisms you have now first, if not get rid of them all together. Do so will make keeping 'SPS' a bit easier>>
I would like to get metal halides for aesthetic and photosynthetic needs of stonies.
<<This is my fave lighting solution>>
I am looking at a fixture that has 2 -- 250W 14K halides (it's a 'Sunpod' made by Current). I am really tempted to get this fixture for reasons as I can pick it up for around $200 on Craigslist.
With 500 Watts of light I would be at nearly 7 watt/gallon here.
<<The 'watts per gallon' rule is a very basic guideline, at best>>
Is this too much!?
<<Nope'¦is what I would use>>
I am afraid I may be better served with 2 -- 150W halides'¦
<<Maybe so'¦but in my experience, for what you wish to keep versus the depth of the tank, I think the 250w metal halides are the better choice providing greater 'flexibility' re stocking solutions>>
only problem being they would cost nearly twice as much. Would the 2 -- 150W's also be enough for stonies in a relatively deep tank?
<<Could be'¦.depending on species selection/placement (Do also be aware that the terms 'stony' coral and 'SPS' coral are not necessarily synonymous)>>
Any advice?
<<250w metal halides would be 'my' choice here>>
Thanks in advance for your time.
<<Is a pleasure to share'¦ Eric Russell>>

Lighting Recommendation (T5 or MH) -- 01/21/10
WWM Crew,
<<Howdy Daniel>>
I am planning an upgrade (within 6 weeks) of my 58 gallon reef/SPS system (36X18X21) to a 150 gallon deep dimension reef/SPS system (36X36X27) and had a question about lighting.
Will T5s be sufficient for SPS corals in a tank with a height of 27inches or are metal halides in my future?
<<Well I have to tell you Daniel, I'm a big fan of MH lighting as I think it provides the best look as well as the most bang-for-the-buck'¦especially on deep tanks. But I have also seen some quite nice systems under T5 lighting'¦including some tanks in the 24' deep range. As long as you maximize the number and wattage of the bulbs over your tank, and place the most light-demanding organisms in the upper-half of the water column, you should be fine to continue with T5 lighting on your 150g display>>
I currently have 6 - 39W T5s over my 58 gallon which has a height of 21 inches and have no problems providing the needed light intensity/requirements for my current corals (Pocillopora damicornis - 6 inches from the water surface, Montipora capricornis - 12 inches from water surface and Seriatopora hystrix - 12 inches from water surface).
<<Indeed'¦but as you demonstrate, placement of the organisms is key>>
I will need to add more light to what I already have for the 150 gallon system but don't know if additional T5s will do the job.
<<They should, yes'¦especially with an eye toward more 'daylight' bulbs vs. 'actinic'>>
I don't want to stack live rock 24 inches high to enable placement of corals for sufficient light.
<<This should not be necessary>>
Also, if metal halides will be required, what wattage fixture would you suggest? (I was thinking about one - 250 watt fixture that would move diagonally across the tank supplemented with 4 - 39W actinic).
<<A single MH pendant on a rail system to track across the tank would be very interesting. A 250w unit would likely suffice, but for such a system I would be inclined to go with a 400w bulb/fixture to maximize light intensity toward the 'fringe' of the lighting footprint'¦and use one of the better 'large' reflectors like the Lumen Max Elite from Sunlight Supply or the Lumen Bright from CoralVue>>
Thanks for sharing your knowledge and maintaining such a great site!
<<The pleasure is ours>>

Sea Stars: Fromia Sp Selection also MH lighting. 9/10/2009
Hi all!
<Hi Eddie.>
Well I've been reading about sea stars lately and know how hard they are to keep in captivity but I've been reading that the Fromia species are one of the "easier" species to care for. my question is does that pertain
to all Fromia species?
<The ones that are offered for sale, yes. Keep in mind though, that 'easier' does not mean easy.>
I've been looking into the red Bali star and the marble stars. in your opinion which is the hardier of the two?
<No data regarding the hardiness of one over the other, do try to pick the best, and healthiest looking star you can. Do acclimate it SLOWLY.
http://www.wetwebmedia.com/fromiastarfaqs.htm >
I have a 72 gallon bow will about 70 lbs of live rock. Also I plan on switching my lighting from pc to metal halides but I'm not sure to go with 2 150watt 14k or 2 250 14k. Would there be a big difference in the two for a 23inch deep tank.
<Yes, a significant difference between the two. Unless you plan on having some very light hungry corals in this tank. You should be fine with the 150 watt lamps.>
Thanks so much and I really do appreciate what you guys do for us.
<Thank You.>

Metal Halide Migraine, fixt. sel.  7/14/09
Hi WWM Crew,
<Hello Amy.>
Thank you so much for your generous help, especially for us beginners! My question is about metal halide lighting, etc.. I have read article after article, only to come to the conclusion that I am overwhelmed and over stimulated on the topic of choosing the correct lighting for our tank.
Since I do not have an electrical engineering degree or anything close to it, I look to you guys... HELP!!!
<Ah, okay!>
I have a 2 month old 150g ( 48"L x 24"D x 30"H ) salt swim tank with 2" sand substrate and about 20 mollies. I should also mention that I live in AZ where my summer tank temp is 74-75 degrees. I currently have a simple old fluor. strip light. Nothing to get too excited about as we are moving SLOWLY. I would like to make this tank into a reef tank and am VERY confused about which lighting is right for my specific tank needs. I would prefer to avoid a hanging set up as opposed to a top mounting set up due to tank location. I just do not want to be limited later in what I can put in my tank because I didn't go for enough lighting now.
Soooo, that being said, please point me to one specific light fixture, no holds barred, that I will be happy with forever, no regrets, so I can check this box and move on!!!
<Well, if this were my tank I would forget about MH all together and look towards T5s. Something like this:
For MH you will want a dual 250 watt setup for a 30" deep tank, for example:
The T5's will allow you to keep what you want while keeping your tank cooler, less of a chance for needing a chiller in the future.>
<Welcome, Scott V.>

Re: Metal Halide Migraine 7/16/09
Hi Scott,
Thank you SOOO much for your infinite wisdom. I attempted to go to the premium aquatics website to look at the T5s you recommended but it got me an error message. Could you redirect me? Again, thank you for your help. I am sure it will save me costly mistakes in the future!
<Ah, what a pain, eh? Here they are again on their own separate lines...funny the links do not work. I am sending you this via my personal email too. Maybe the HTML encoding will help. Welcome, Scott V.>

Halide lighting decision 4/3/09
Hello everyone!
<Hello Shelli!>
I have read over your site every time I have a question, and usually it's answered by reading the questions of others or the insightful articles, but I am not quite sure about this one. (I am sorry if this is somewhere else, but I couldn't find it).
<OK, no problem.>
I am planning on upgrading to a 150 gallon tank (currently I have a 55 gallon). I only have PC lights on my 55 gallon (4 65 Watt bulbs - two 10,000K and two actinic) and as such I only keep a few softies, mushrooms, and a hardy LPS. They are all doing well, but I am researching MH lights and I'm not sure how many and of what wattage to put on my tank. I am looking to get a 4' 150 gallon, so it will be about 2.5' deep. I want to keep similar corals, maybe adding some more LPS and zoos. In the distant future I might want to get into SPS, but not with my current inhabitants. My question is this: I am looking at two different
fixtures, one is 2 x 250 watt MH with a 4 x 54 watt T5 (I don't know if I 'need' the T5s, but I like the aesthetics).
<They are a nice addition.>
The other is 2 x 400 watt MH with a 96 watt PC bulb. Do you think the 2 x 400 watt fixture
is too much for the tank?
I'm just worried about the amount because the tank is fairly deep. Also if this was your tank, could you think
of something else that would be more optimal? So would the 2 x 250 be appropriate for my current inhabitants but would I want the 400 watt fixture if I wanted to keep SPS in the future?
<Na, the 250's will do in either case....do also just consider a T5 fixture. You can keep SPS with T5s very easily and it will save you cash on power for lighting and cooling the tank.>
Thanks in advance for the great advice!
<Welcome, Scott V.>

Metal Halide Query Not Posted In Today's Dailies   3/31/2009
Hi Bob,
Hope you left a few bottles of beer in Coz for others to enjoy.
Yesterday, I answered a query concerning problems with lamp replacement and a ballast problem and see it was not posted today. I answered and deleted as normal.
<QUICK, like a lagomorph, check the DELETED files on the mail site for WWM... I did not see this in the SENT folder... may well be in the deleted.
If so... send back to the SENT. B>

Lost Metal Halide Query   3/31/2009
<Big J>
Now you want me to assimilate the speed of a rat at my age. Nothing doing.
I just saw that I received a response from the gent I got the query from.
Will answer sometime today and delete which should allow you to post both.
Unless I'm in a time warp,
<I assure you we are>
I just do not recall seeing the query. It's in my inbox if you care to take a look. You are a few years younger than me and might remember more.
<Doubtful. Be chatting, B>

Metal Halide questions--help asap 3/30/09 <James, this was posted ayer. RMF>
Please help ASAP!
I am still new to reefkeeping and am having a problem. First of all, I heard that MH lighting was the best. I have a 55 gallon tank, so I found a used MH fixture online used at a very decent price. The fixture isn't labeled anywhere so I am not 100% sure of the brand.
The fixture is 48" long, and contains 2 250W MH double ended bulbs. The outer edges are actinic bulbs, and down the center led moonlights are. My tank has been running wonderfully for around 8 months and mixed soft and hard corals, along with fish have thrived. Is it too much light though for the tank?
<I little overkill for a 55, but for keeping light loving corals/clams, should not be a problem as long as your tank temperature isn't going through the roof.>
The bulbs are labeled 20K blue 250W. I was told the fixture was a Corallife brand.
Now for the problem. A few days ago 1 of the lights went out. So I attempted to narrow down the cause to ballast or bulb. I unplugged the working light and hooked up the ballast to the none working light.
Nothing. So narrowing it down I have isolated the problem to be bad bulb on one side.
To confirm this I attempted as many combinations of hookups. No matter which ballast was hooked up. Only the same light would work. So I order a bulb online. I order a CoralVue 14k 250W double ended bulb, disassemble and install the bulb. Still nothing. So I pull out the bulb that was working before, put in the brand new bulb, and again nothing. I swapped and tried every combination I could.
Results--1 bulb working in both fixtures with both ballasts. Bulb would light up almost immediately.
New bulb, & other bulb--would not work in either fixture.
<Well, one bulb was gone to start with and I'm guessing your problem may lie with the new CoralVue lamp being a probe start type lamp, and your ballast is a pulse start.
Most 250 watt DE lamps are pulse start. Pulse start lamps do not have a starting probe electrode as in the CoralVue, but start by way of a high voltage pulse, typically 3 to 5 kilovolts.>
I've got records on most bulbs that indicate the start method and type of ballast required, but CoralVue is just listed as a ? but it is a probe start lamp. Problem here is most folks think any HQI lamp will work with their ballast and that is not the case.>
So I thought I would just leave 1 working for now, and I put it back together, set it atop the tank. Roughly 3 minutes later the working bulb explodes.
<Didn't like that.>
Now all I have is my actinics running, with a lot of livestock in the tank.
How long until I get this fixed before I have major die off?
<To be safe, I'd say a week for light loving SPS/LPS. Could be longer, but I wouldn't want to chance the Zooanthellae dying off which is called bleaching. I am assuming you have corals and as the fish without light, it isn't going to be a problem.>
What do I do? Is it possible the ballasts are too weak to light the bulbs?
The ballasts do not have labels, they are encased in metal with a switch, and removable power cable.
<Is there a manufacturer listed on the old lamp itself? If so, replacing with that brand/type would ensure you would have had the right lamp for the ballast you have. There are no numbers stamped on the ballast itself, like an "M" and a number? Best to take the fixture to a local electrical shop and see if they can test the ballasts for you before investing in more lamps.>
Help Help help! I can give more details.
Thanks for your time.
<You're welcome you poor dude. James (Salty Dog)>

Re Metal Halide questions--help asap 4/1/09
Please help ASAP!
Thanks for the response.
<You're welcome.>
More research done yesterday. Found out my fixture is an Odessa 48".
From the forum discussions this a terrible and cheap fixture.
The recommendation is that the stock ballasts with the unit only have enough power to push maybe 160W. Everything I have read recommends updating the ballasts.
So yesterday I ordered 2 Icecap 250W ballasts. Another $260 investment. I really really really hope this works, and the Icecap will power the new 14K CoralVue bulb.
<Ice Cap does state this ballast will power any 250 watt MH lamp, so you should be good to go.>
I plan--if it works, to light up 1/2 the tank with the new bulb, more the light loving coral there. Then order another bulb for the other side of the fixture.
Do you recommend using the same type and k-value bulbs for the whole tank?
Or for example can I have a 14K on one side and a 10K on the other side?
<No problem doing this, but I think you will not like the look.>
I have been forced to learn a lot quickly and your advice is greatly appreciated.
<You are welcome my friend.>
With my case of too big light for shallow tank, what K bulb and brand would you recommend? Should I move soft coral to one side and hard to another?
<No, I'd just go with two 14K lamps. I use Corallife lamps myself but I'm not saying they are the best out there, I just happen to like their 14K look. All 14K or other temperature lamps for that matter will not necessarily look the same as far as color appearance goes, some may be slightly lighter and some slightly darker in the blue range.>
Livestock consists of:
Spaghetti leather?
2 toadstool leathers?
many types mushrooms
many types of polyps
Hammer Coral
Brain Coral
red Montipora
yellow Montipora
chili coral?
hard/stony coral--not sure which kinds.
1 Clarkii clown
2- percula clowns
1- chromis
4- blue damsels
1-cleaner shrimp
2- peppermint shrimp
hermit crabs
2- brittle starfish
Your help is greatly appreciated.
<Again, you're welcome. James (Salty Dog)>

MH Retrofit 3/20/09
<Hi there Kiet.>
I am interested in purchasing a MH retrofit for my 125 gallon. I saw a pretty good deal online for one made by a company called Captive Sun. I was wondering if you have heard of this company or any experience with their products.
<I have, fine stuff.>
Their 72 in retrofits includes 3 metal halide moguls and a setup for 160 watt VHO bulbs rather than the standard 96 watt PCs.
<I personally prefer VHO actinics over PCs.>
Also, with my tank (6 ft long), I should go with the 3 moguls and opposed to the 2 right?
<Would be better, yes.>
Thank you,
<Welcome, Scott V.>

Re: Lighting Question, MH... 55 gal., SW, waste heat concern     I'm so very sorry to bother you again, but I have run across more conflicting info in the FAQ's and have another question. <No worries, Matt. This is why we're here.> Since my tank is a standard 55gal, would metal halide lighting be too hot and burn everything up? I have seen that it is recommended not to use MH lighting on a 55gal tank, but have also seem recommendations to use 2 150 watt MH pendants above this same setup. All of this conflicting info is starting to get confusing to me. Any input would be greatly appreciated. If the 2 pendants would be fine, how far above the tank should I keep them to minimize evaporation and bleaching of my corals? <First, let me preface this by reminding you that every set up is different. So, just because someone had heat issues with MH lighting over a 55gal that does not mean your set up will as well. Whether your tank will overheat depends on several factors. First, what is the highest temperature your tank has reached with your current lighting method? If it is in the upper levels of the acceptable range, then you should consider using more efficient equipment (such as cooler running return pumps or circulation powerheads) and/or increase cooling (by adding a chiller or fans) before upgrading to MH. Second, not all MH setups are the same as some are terribly inefficient. Consider going with a proper MH set up with a quality electronic ballast like the Icecap 150W ballast and bulb like the Phoenix 14k to maximize efficiency. Review this site for more information on efficiency: http://www.manhattanreefs.com/lighting. For reference, I live in Southern California where ambient temperatures can be quite high in the summer and I am able to hang a 150W MH set up 12" over my 24 gallon Nano Cube. I use a fan to blow cool air over the water surface to increase evaporative cooling and water temperature is table at 80-81 degrees even on the hottest days.> Thanks again Matt <You're welcome. Cheers, Minh Huynh.>

Metal halide fixtures  9/29/08 Maybe I overlooked it, as well as undereducated in some aspects, but can metal halide ballasts and hoods made for growing plants indoors (hydroponic farms) be used with different bulbs over aquariums? <Mmm, with some provisos, yes...> The reason I ask is that I have come across a place where I can get some 400w metal halide ballasts and hoods for a ridiculously cheap price. <Well... can you really use such high energy use, waste heat producing units?> I don't have any experience with metal halide systems, but am researching them for my new 150g <Mmm, not likely a good idea here... too high wattage for this size, depth... more downsides than use... I would stick with 250 Watt or less units> reef tank that I have and am still in the process of setting up - my 3rd reef tank. Are there specific bulb sizes I should make sure the ballasts accept? <Oh yes...> Thanks for any insight. <Mmm... and issues re water- and splash-proofing... the long and short of this, by and large I would use only "aquarium intended fixtures". Read here: http://wetwebmedia.com/marsetupindex2.htm the last couple of trays. Bob Fenner>

Using Metal Halides 1/24/08 I just purchased an 48" Outer Orbit 2 150 watt 10 K HQI-MH w 2 130 watt 6 Lunar lights. I have a 90 gallon 24" deep aquarium. I had a nova extreme t-5 54 watt x 8. I didn't have very good luck with it staying on after about 6 months. <Not good.> I have my tank stocked with some fish and a few corals which consist of a torch coral, a colt coral, a toadstool and some mushrooms. I have it hanging 6" above my tank right now. Is that enough or should I raise it more and to what height? <Sounds like a good distance, you can always raise it a bit if you have temperature issues.> I would like to start raising a clam or two and some more stony corals. <Will be fine, I would try to place the clams (especially Maximas or Croceas) in the upper half of the tank.> Thanks for your help crew, Bob L. <Welcome, happy reefing, Scott V.>

MH lighting for a 125gal 6' long tank 11/5/07 Dear WWM crew, First of all thanks for your continued excellent support for the reef keeping community. Keep up the good work. <Thank you Isaac.> Now onto my question, I'm moving from a 37gal FOWLR tank to a 125gal reef, that is a 6 foot long tank. I will be keeping mostly LPS corals and clams. Don't know if I want to keep SPS, most likely not. Now comes my lighting dilemma. Since the tank has a big ugly brace right smack in the middle, if I get 3x 175W MH lights will the middle light be blocked out and mostly wasted? <The light is still very usable, although not quite as intense. You will need to clean the center brace periodically, it will make a big difference in light penetration.> (I'm not interested in designing and making my own hood, so I will only get pre-made ones.) The other option is I could get 2x 250W (in pendants, possibly going with PFO), but obviously this will exceed the commonly suggested 2 feet of linear tank length per MH bulb. <I have seen this done with this particular sized tank. It works, but you will have to stock the tank accordingly considering that the center will have noticeably less light. Just depends on the look you are after.> For the animals I want to keep, is this going to be sufficient, not enough PAR or even overkill (is even 2x 175W enough?). Besides tank inhabitant health and growth, what about aesthetics? Will the 2x MH lights create too much lapse? <It really depends on your personal taste. If you want the tank to look uniform I would go with the 3 X 175W. This will be plenty if stock you clams in the upper half of the tank.> P.S. Color temp will be in the 10k-13k range. Thanks, Isaac <Happy reefing, Scott V.>

SW Lighting, reading re MHs  - 7/23/07 Dear WWM crew members, <Pedro> I appreciate all of your wonderful support and knowledge. I have a question on metal halide lighting for a 90 gal reef tank. If I wanted to keep SPS such as acropora spp. would a 2x250watt 14k MH fixture 8"-9" from the surface be too intense for the coral if placed in the upper half of the tank? <Mmm, nope> Or knowing that the lighting fixture would be 8"-9" above the surface of the tank, would I be better off having a 2x150watt MH? <Depends... you could "match" other aspects of husbandry to the higher wattage fixtures... but if you "had time", weren't interested in boosting metabolism... You could get by easily with the 150's> If I had a 2x150w metal halide fixture about 8-9 inches from the surface, would I still be able to place corals anywhere in my tank? Please notify me ASAP. It would be helpful if you guys/gals could tell me which is better, 2x150w or 2x250w for SPS and other corals. Peter <Please read here: http://wetwebmedia.com/marsetupindex2.htm the tray at the bottom. Bob Fenner>

Interchangeability Of Components Of Coralife Aqualight Fixtures -- 07/19/07 I'm setting out on a new adventure... a 180gal reef tank. <<Cool!>> It will replace my 55-gal reef tank (all residents will eventually be transplanted to the new, larger tank). I've worked out all the details, pricing, etc... except for one thing. I have an opportunity to get a great deal (less than half price) on a Coralife Aqualight Pro. <<I see>> It's the 72" fixture with three 150W 10K's. <<Should do nicely>> The tank will have these residents: Galaxea Pagoda Cup T. Crocea T. Derasa There are several others, but these are the ones in need of the most light by far. <<Okay>> Also, they would be kept high in the tank (except the T. Derasa clam, he likes his sand). <<Indeed>> Questions: 1) Will three 150W 10K's be enough? (My math says no since that's only 2.5Wper gal). <<The 'watts per gallon' logic for determining lighting requirements is really a very poor method in my opinion. There are so many factors that determine 'what is adequate'...e.g. water depth, water clarity, requirements of the individual organisms, color temperature, feeding, etc. If you were planning to keep shallow water Acroporids I would suggest more wattage; and even then not because the corals couldn't live under your planned configuration, but because I think they would 'color' better under the higher wattage lamps. But with what you have listed, the 150W lamps w/10,000K bulbs will be fine>> 2) If I take the two ballasts and bulbs from my current tank's Coralife Aqualight Pro (48" fixture with two 250W 10K's and ballasts to match), could I replace two of the 150W ballasts/bulbs with the 250W ballasts/bulbs? <<You could...but you will also have to change out the bulb brackets/holders as these for the differing wattages are not compatible/interchangeable>> Are the internal components of the fixtures compatible or would I burn something out? <<Being from the same manufacturer it is highly likely they are virtually identical on the inside but for the ballasts/bulbs/brackets>> 3) If what I discussed in question 2 is a possibility, would the resulting 650W total be enough for these residents (3.6W per gal)? <<More than, yes>> If not, what should I shoot for? Any brand/model recommendations? <<I think you are fine with the 72' fixture mentioned>> Thanks so much! ~Eric <<Happy to assist. EricR>>

Re: pix of the day, magma MH use  -- 06/11/07 Very true, it does change weekly. I don't dare to venture into the possibilities of next month. Off the top of your head, do you think 2 400w MH and 2 110w VHO actinics are too much for a 75 gallon? <Yikes! Too hot (temp. and electrical cost) for me...> I am wondering if I might be better off with what I already have. <For now... BobF> MH Lighting Choices - 3/27/07 Hi there, You guys are the best. <Thank you for this, my friend. JustinN with you today.> I have a 125 gallon reef ready system.  Live sand, Live rock.  Right now I just have a goby, cleaner shrimp, and tomato clown.  I am wanting to get into inverts, and corals. I need a stronger lighting system.   <Ok> I am looking at a 785 watt. (3x175 MH and 2x130 watt blue actinic), or a 1134 watt (3x250 MH, and 4 96 watt blue actinic) each with led moonlights.  Is there such a thing as overkill with lighting?   <Certainly> Which would you recommend.  They are both 72", and have external ballasts. and about $150 difference.  They are Odyssea lights.  I know it depends on what kind of corals, or inverts I want to keep.   <Bingo> But should I just go with the bigger one and be able to support light for just about anything.   Is there any other tips you can give me on lighting situations.  This is my first adventure into MH's.   Thanks for any advice. Aaron <Well, Aaron, my thought is that the 3x250w would be overkill. I have a good friend who runs a 120g beautiful reef, and has lit it for over a year using the 2x175w solution that Odyssea offers with great success. Of the two fixtures in question, I would likely go with the smaller. Less heat to deal with, save yourself some money as well. Hope this helps! -JustinN> Metal Halide size and T5 question   3/1/07 Hi, Larry here. <BobF here, hello> I have a standard 75g 48" reef tank with softies and a few LPS under PC lighting.  I want to make the jump to SPS and clams.  I have the opportunity to buy a MH fixture with 2x250w HQI MH's and 2x96w actinic PC's.  Is this going to be too much light for my softies an the 3 fish and shrimp in the tank. <Mmm, can be acclimated to this amount, kind of light for this size, shape system... either by elevating fixtures or using screening likely... unless you have dimmable "ballasts"> I'm also concerned about the heat issue.  I have considered a fixture with dual 150w HQI MH with the 96w PC's.  Which do you recommend? <A tough one... as both can/will work...> I can get the 250w fixture at a big discount. I was also thinking about Nova extreme HO T5 fixture 432watts with 8x54w T5 bulbs, 4x460nm actinics and 4x10,000k bulbs.  Will the T5 lighting be enough for SPS and Clams? <It too could work> The T5's are nice because you have so many lighting options because of the 8 bulbs.  They also generate less heat and the bulbs supposedly don't have to be replaced as often. Thanks again for your help. <Well... you do have a choice to make... Don't know that sorting through the many articles and FAQs files on marine light/ing on WWM  will help here... If it were me/mine, and I had any notion that I might one day upgrade to an even larger system... I'd go with the 150 watt MH's. Bob Fenner>

Re: Metal Halide size and T5 question, Flagfin angel dis./recovery  3/1/07 Thanks Bob for the prompt reply, <Welcome Larry> I think I'm going to go with the 150 HQI due to heat issues. I just needed to make sure that I could keep SPS and clams. <Ahh, this would be my choice as well> I'd like to share a success story with you about a sick fish since you here so many failures by hobbyists. <Please do> I have had a beautiful Flag Fin angel for 3 years.  It became ill when one of my older fish died and I didn't find out till 2 days later.  The angel developed bilateral cloud eye, fin rot, hemorrhagic patches on both sides of its abdomen and mouth. I immediately place it in my QT tank. It progressed very rapidly and the fish just labored at the top of the tank. It was literally knocking at deaths door and I thought about euthanizing it. I started treatment right away with 2 antibiotics, penicillin and furan along with every other day FW and methylene blue dips and every other day water changes to my QT tank.  Well now I call the angel the miracle fish.  Its almost back to normal except for some residual damage to one eye. This fish did not eat for 12 days and now its swimming around the tank and just starting to peck at food.  Its not completely out of the woods yet, but if it starts to eat again I just may get lucky. <Yes... your diligence has paid well> By the way, I'm a emergency medicine physician and  my wife and friends are calling me the fish doctor. Have a great day and thanks for the help. Larry <A good title. BobF>

MH Upgrade...Options/Considerations - 01/18/07 Thanks for all the help over the past few years!!! <<Has been a pleasure to assist>> I am running (4) 65 Watt PC bulbs, two 10,000K bulbs and two Blue actinic. <<Ok>> I have a few LPS and mushrooms and about 6 fish in a 100 gallon tank. <<Mmm, this lighting seems a bit "weak" to me for this size tank...even considering the livestock you have>> The tank has about 100lbs of live rock and my sand bed is about 3-4" deep.  My tank size is 23" tall by about 60" wide and about 18" deep.  I want to add MH lights to this aquarium and add SPS, but probably no clams. <<Okay...do think to acclimate your livestock to the new/more intense lighting when you do this.  Have a read here beforehand: http://www.wetwebmedia.com/acclimcoralslight.htm >> I was wondering if running (2) 250watt MH bulbs with 10K to 14K bulbs would be enough, or should I keep a set (2 bulbs) with 65watt actinic also with this set-up? <<The halides in either Kelvin temperature would be fine on their own, but many folks opt to keep actinics in their tanks as well to enhance the "glow" of their corals...and for my use, they're handy for "softening the blow" when the halides go out at the end of the day when set to come on a bit before, and go off a bit after, the main lights>> I have a chiller that I have not hooked-up yet, but it is available. <<Very good...though not always a necessity>> Is 250watts too much, or would 175watts be better? <<Depends much on the particular needs of the livestock you will ultimately have, as well as depth of placement re, water clarity, even what Kelvin temperature/bulb type/bulb manufacturer you choose.  The 175-watt, and even 150-watt halides would probably suffice for most instances...but I would likely choose the 250-watt halides myself for this tank just for the added flexibility (wider range of intensity available by adjusting the fixture up/down)>> Also, how high should I place the bulbs over the tank? <<Usually 8" - 12", also dependent upon the factors already mentioned for wattage selection>> I want to put them in my enclosed hood as a retro fit. <<Mmm, I see...that may change my thoughts then.  In my experience enclosed hoods with metal halide lighting are quite limiting.  The distance between the water and the bulb is usually "fixed" and often quite close...exacerbating the issues of excess heat, mineral buildup in the bulbs or UV filters, even bulb breakage from splashed water.  Not to mention ventilation is usually not the best...especially if the hood was not originally "designed" for metal halides bulbs.  I'm not trying to discourage you from making this change/modification...just wanting to make you aware of the challenges re.  With these considerations in mind, the lower wattages might be the better choice>> The hood has fans, so heat should not be a problem. <<You'd be surprised...do consider adding extra fans or openings for additional air flow>> I just don't want to burn the other corals. <<Acclimate them as explained in the article I referenced you to read>> Also, how long should I run the lights during the day and how long to run them for acclimation purposes? <<Anything between 10 - 14 hours per day should be ok...I tend to run mine at the longer end of the spectrum (six bulbs on for 11-hours individually but with 30-minutes between sequenced on/off timers...13 1/2 hours from the time the first halide comes on till the last goes off) Also, these are one-sided bulbs and not double-ended bulbs so I was wondering also if I should place them perpendicular or parallel to the tank? <<Ah, okay...so probably the 175-watters then.  Parallel to the tank/hood is the most common installation here.  Two bulbs will be "stretching it" as far light coverage goes, depending on the quality of the reflector in the hood and the ultimate distance from the water's surface of the bulbs you may find you need three bulbs for adequate coverage/an even "look">> Thanks, Jeromy <<Quite welcome.  Eric Russell>>

MH lighting, mis-stocking in a too small SW system   11/19/06 I am  trying to make sense out of what I am about to say to you guys, <Appreciated> anyways I recently purchased a second 150 watt energy savers unlimited tank mount metal halide because one did not cover my entire 58 gallon reef tank. The occupants are a golden angel, <Mmm... aurantius? Needs much more room> two percula clowns, yellow goby, and a dwarf hog. Coral are elegance, <Dangerous to crowd, have in small volumes> hammer, mushrooms, xenia, and a toadstool, <Do be diligent here re water changes, switching out chemical filtrants... I would not add any other invertebrate life.> there's 300 watts of light total and for one thing it seems to be to much for the angelfish, <Yes... I would only use one such fixture here> also my electric bill is going up more than I thought it would, <You are wise to be aware here> so I was thinking instead of buying a new set of lighting could I reduce the length of time the lights are on right now its about nine hours a day, or could I get away with just using one halide and centering it, <This is what I would do> that would give me 150 watts of light. I also forgot to mention that there is a rose bubble anemone in the tank, Thanks Ron <... you should take the time to read re each of these listed species "Systems", "Compatibility"... on WWM... some potential disaster looming. Bob Fenner>

Re: MH lighting, mis-stocking in a too small SW system  11/20/06 After writing to you I am considering taking some animals out whats the logical move Thanks Ron. <To read as you've been instructed... determine "who stings who" most... what you'd like to, can keep together. BobF>

Photo-Shock? - 10/29/06 Good Morning... or afternoon, or evening, whatever it may be. <<Hello...morning now>> I am in a real mental pinch here with my halides and looking for a shoulder to lean on (hopefully not cry on). <<Let's see if I can be of assistance...>> I think I goofed big time, but then again, it's reef keeping so before I jump into trying to fix things, I thought I would ask someone with a little more experience first. <<Ah yes...go slow and research/analyze your options whenever possible>> Here is the skinny.  I just undertook a two-month project to build my dream system. <<Only two months? <grin> >> Got the okay from the wife and took the plunge. <<An "always important" component>> I had a 105G tall (32"-deep X 48"-long) for three years with a 30G sump/fuge combo.  I keep acros mostly, <<'¦me too>> and have around 18 different species as well as a few other SPS, a rose bubble, and a Crocea. <<Ack!  You were doing so well up until the anemone...>> In my 32" tank I had 2X400W halides about 10" off the water and life was good. <<A lot of light>> Currently I have framed a 125G (6 foot long X 22" deep) display into a wall and made a 12X6 foot support room behind it. <<Cool!  Love "in-wall" displays (is what I have)>> The display has a 100g sump, 75g refugium, 30g prop tank, and I even got to tie in my 30g anemonarium which was really great. <<Lots of water volume...excellent>> I drip Kalk 24/7, dose 2ml of iodide daily, and maintain a daily avg of: 425 CA, 9 DKH, 1.026 SG, 8.28 - 8.36 pH, 79.3 - 79.6 degrees, 0 nitrates, 0 PO4. <<Very good>> I use RO/DI that I aerate/buffer as needed and change 20G of water every Sunday.  I am very happy with my parameters, however I am not so happy with my corals. <<...!>> Since I had the 2X400W halides from my deep tank, I just picked up another reflector/ballast/bulb and am now using 3X400W halides over my 125G display, which is only 22" deep. <<Mmm...>> I had the halides at 10ish-inches from the water surface that I now realize, or think at least was way too close and have moved them to 16. <<Indeed'¦the corals could have been/can be "acclimated" to the light intensity, but this would need to be a "gradual" process.  The organisms we keep are quite adaptable...but they don't usually handle "rapid" changes well>> I have noticed that my Pocillopora and a couple of Acros that made the transition have started to lose their rich color for a more "watery" color.  Some red/pinks are fading to white, blues have gone pale, my rose bubble just sticks a couple of tentacles out of a crack in a rock, etc.  Nothing is bleached; they are just not how they should be. <<Does sound like photo-shock>> At first I thought the color change was because I switched from XM 20Ks to Radiums when I setup the new system, however I noticed that my best colored coral is a purple-rim/green M. capricornis that sits almost directly under the center brace.  Also the more I have been reading on WWM the more I think that the power/distance is the real culprit. <<...?>> To cut to the chase here, am I "making lava" as Anthony calls it, keeping the 400s? <<400-watt halides are definitely more light than you need on a 22"-tank, but by raising the fixtures/acclimating the organisms it can be utilized>> Should I downgrade to 250, or do you think that the 400 at a higher set point will be all right? <<Downsizing the lighting will be cheaper to run/less excess-heat hassles...but the 400-watt lighting can be used as stated>> Perhaps I have missed the boat entirely and you think that something else might be going on? <<This too is a possibility, or at least a contributor...reactions to changes in water chemistry, feeding, additives, or just being moved/repositioned in the new system.  But I think the lighting (due to lack of proper acclimation re) is likely the main cause for the changes in color/behavior you describe>> I am all ears and can't even begin to tell you how much I appreciate your time to read this long-winded email and already feel better knowing that one of you at WWM is going to chime in on this issue. <<No worries mate...is what we do.  Have a peek here re acclimating your corals to the new lighting: http://www.wetwebmedia.com/acclimcoralslight.htm>> Again, all my gratitude, have a good morning/day/night =) Jeff <<Happy to share.  EricR>>

LIGHTING CHANGE Short and simple, crew.  I currently have 360 watts of Comp  Fluorescents over a 90 gallon.  I am interested in a 2 x 250w, 10,000K  Halides, with 2 x 96w actinics.  Is it too much, would I be better off with  175's? <Simple answer is that it depends on what you want to do with the lights, what animals you wish to keep. MacL>

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  >>

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