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FAQs about Metal Halide & Halogen Lights and Lighting for Marine Systems 7

Related FAQs: Metal Halides 1, Metal Halides 2, Metal Halides 3, Metal Halides 4, Metal Halides 5, Metal Halides 6, 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,

Disposal of metal halide bulbs and ballasts 12/15/11
Hi crew,
<Hello Andrew>
This seems like an odd question to ask you, but you are so knowledgeable and helpful in all other matters related to fish keeping, that I thought I would try.  I need to dispose of 2 old metal halide ballasts along with some bulbs, and was not sure if there were any special disposal requirements.  I know a lot of these would be locally driven (am in Toronto Canada) but I figure you know more about this than anyone I could find to ask here. 
<I'm not a bit familiar with any Canadian EPA guidelines/requirements so I would advise you to contact local authorities as to proper disposal of these items.   Our local Home Depot Store has bins for lamp and battery disposal.  Ballasts are treated much the same as batteries.>
Thanks in advance for your help. 
<You're welcome.>
You guys (and gals) are awesome!
<Well thank you Andrew.  James (Salty Dog)>

Halogen lights and regular aquariums  1/5/11
I have a 20 gallon long with the usual fluorescent lighting. I have it backed against a window that gets a lot of sunlight. I have a background, so I am not getting algae, and I rarely use the top light. I notice that
they now have Fluval tanks. They are never bigger than 10 gallon.
<Do you mean the Fluval Edge? This tank contains about 6 gallons. It's very, VERY limited, and unfortunately while the instruction manual explains this, retailers often don't, and these tanks are VERY difficult to stock. A few personal thoughts here:
I believe they are lit with Halogen lights.
<Yes, of the sort used as domestic lights rather than the high-output sort needed to grow plants and corals. They're housed in a unit that keeps them dry yet adequately ventilated and cool.>
I was wondering if there is anyway to get that effect with a regular aquarium??
<Any spot lamp a few inches above the water will create ripples.>
Are halogen lights really hot??
<Yes, and explosive if they're hot and splashed with water. Don't "do it yourself" unless you're an electrician with expertise working around water. If you're not qualified to work this way, stick to using halogen systems expressly designed for the aquarium hobby. In all honesty, upgrading to LEDs rather than halogens makes infinitely more financial, safety, aesthetic and environmental sense.>
The lighting effect is like peaceful early morning or evening light. Thank you!!!
<Cheers, Neale.>

Lighting Combination Question, MH reading  -- 02/12/10
I have a 90 gallon reef tank with mostly LPS, a few softies, and 1-2 SPS corals in it. My lighting houses 2x175W metal halides, as well as 4x65W PCs. I want to have my PCs as actinic, but was wondering what temp you recommend for the halides? I'm debating between 10k vs. 14k. Thoughts?
<Read here: http://wetwebmedia.com/mhlampfaqs2.htm
and the linked files above that appeal to you. Bob Fenner> 

Metal Halide Pendants 8/7/09
I have two 175 watt MH pendants sitting on the glass top of my reef tank.
<Do you mean above the glass? Sitting the pendants actually on the glass will eventually lead to cracking the pane.>
Does this reduce the spectrum in any way?
<Yes it does, to what extent can vary a good bit.>
The pendants themselves have glass shields. Someone told me this is like trying to get a suntan thru a window. My goal is to add a few SPS. Will this pose a problem?
<It will be fine. The glass does filter out some of the light, scatter a bit of it about keeping it from penetrating as intensely into the tank. But there is still plenty of light there for SPS.>
I do not have a problem with temp. It ranges from 78-80.
<Do also check out: http://www.manhattanreefs.com/lighting.
Look at the PPFD value for the bulbs, the measured "usable" light. You can check most bulbs with and without the glass shielding to give you an idea of the effect. Scott V.>

250 Watt MH for a 16" Depth? -- 02/03/09 Greetings crew! <<Hiya Aldwin!>> I've read thru the archives already. <<Very good>> I just wanted to confirm that you guys think 250 watts MH for my 16" tall (36" long, 24" deep) tank would be too much? <<Maybe not 'too much' depending on livestock kept, bulb type/color, distance from the surface of the water, water clarity, etc'¦. But I think it is very likely this is more wattage than you 'need' here>> I wanted to go for a single-ended bulb, so I'll see if I can find something smaller. <<A 175w or even a 150w MH would do fine here I think>> If 250 watts is too much, can I still use a 250 watt bulb, but with a dimmable ballast that will operate at 55%/85%/100%? <<I've seen some dimmable ballasts out there'¦and while this may be an option for you, going with a lower wattage system will likely be less costly overall>> I currently have a Solaris system for my mainly softies/LPS tank ... but wanted to do more SPS's. Thus I wanted to do MH. <<I see'¦ I still think you'll be fine with a 175w or 150w system>> I was actually thinking of pushing my Solaris to half of the tank, and my 2 MH bulbs to the other half. I can control the intensity and the blue/whites of the LED's very easily and thus can maintain more gradual light changes. <<Okay'¦give it a try>> Take care crew! Aldwin <<Cheers mate, EricR>>

1000w Metal Halide 11/6/08 Okay. I'm throwing this out there and I know it may sound crazy. <We all are at times!> I have been in the SW tanks for about 7 yrs or more. I started with the old fashion florescent. Then a few years ago I updated to a 260w Compact florescent system on my 55g. Well I have a 125g that I am setting up and a need a better lighting system. I am going with a metal halide system that I want to do myself. I was going to go with 3 250watts but the price is going to be up there. Someone locally is selling some metal halide flood lamps for $25 complete which sounds great cause all I have to do is change the bulb since its basically the same ballast. The problem is that it is a 1000w each. Here's the question. Can I really go with 1 1000w metal halide bulb for a 6ft tank and try to make a reflector to shine on the whole tank.  I'm pretty sure you will say go with the 3 lights but will this work? <I will suggest the three bulb combo. Do consider the retrofit/DIY type systems, can save some big bucks here. A reflector will just not be able to adequately spread this bulb.> Budget!!! <Do consider 750W vs. 1000W. At 30 cents a Kw/h, 10 hours a day, it works out to a $22.50 a month difference! You would have fewer bulbs to replace, but the selection in the 1000W range for reefs is small end expensive.> Thanks <Welcome, Scott V.>

MH vs. HQI? What is the difference? 08/14/2008 I often see MH and HQI used very similarly but once in a while I see that one is better than the other. Can you please help me understand the difference between the two? I thought I read that HQI is a subset of MH, is so, what do we call the non-HQI MH bulbs? My perspective is someone building up a 175g 25" water depth tank that will eventually be home to anemones and perhaps corals. <<In basic terms, HQI is just a type of metal halide bulb. Commonly, there are two types of halide bulb. Single end which are mainly called a "mogul" fitting, and the HQI bulb, which is a double end fitting.>> Thanks Joe <<Your plan of a tank sounds superb, Joe. Hope this helps. A Nixon>>

Re: My Poor Brain, Hello again! Quick question about lighting. -04/11/08 Will I notice much of a difference if I switch to a dual 175 watt electronic ballast? I currently am running two magnetic ballasts. I have heard they consume more electricity and fluctuate more throughout the day. <This is so> I would like to switch to 14k bulbs, will this be sufficient with the soft coral in a 2' deep tank? <Mmm, yes... possibly some acclimation/adaptation...> Or would I benefit switching to 20k 250 watt bulbs? <See WWM re... I would not switch to the higher Kelvin rating for functionality sake... and only to higher wattage if you can/intend to match other aspects of physiology here> I do like the 20k look, but not sure if I can get away with it using 175 watt. <Will include your prev. corr. below... for this size/shape volume (a 65 gal.), the 175's will be fine> My canopy will not allow a HQI fixture unfortunately. Thank you for your help! The brain is doing much better, no noticeable regrowth, but the recession has stopped. Rob <Ah, good. Bob Fenner> WetWebMedia Crew <crew@wetwebmedia.com> wrote: Help with my Brain? he means the one in his tank) Hello! <> I have a 65 gallon (love this size!) tank with a built in overflow. The overflow has a 1" drain and a 3/4" return. (MegaFlow my a$#) They both are used as drains, the 3/4" goes to my refugium. It is a 30 gallon rubber tub with 4" live sand and Chaeto that completely fills it! The 1 1/2" bulkhead drains from this refugium into a ten or so gallon area that houses a DIY skimmer (very pleased with it!), heaters and carbon. This area also receives the water from the 1" overflow on the main tank. Water is then run back to the tank via a "little giant mdc-x" I believe. It is rated 1100 per hour. Water is run into a 1" pvc closed loop with four 1/2" outputs that were heated and squeezed at the ends. <> Main tank; 1/2" to an inch of crushed coral 104#s of live rock No fish, <> three fingers, a green toadstool, a red and teal open brain and a couple mushrooms. All up and running for over a year. The tank is lit by two 175 watt bulbs, one 10k and the other 20k. The refugium is on reverse light cycle and is lit by two 65 watt 12k pcs. Water; nitrite and ammonia-0 nitrate-0-.5 pH-8.2 Alk- 13dkh calcium-ran out of the tests..oops was around 450 temp fluctuates between 77 and 80 <> I have no algae problems and everything is quite stable. I prefer light stocking, although I want to add more a little at a time. Okay, several questions! My open brain has bad tissue loss, it has reached one of its mouths! I admit, I have been on the road a lot lately and have neglected my duty a bit. There were probably times where it was fed only once a week, maybe less! I know..its not fair to the animals! It still eats, in fact I am still able to feed the mouth that is reduced to half its former glory. I am feeding fresh gulf shrimp and clam. I will feed it as often as it will eat until it hopefully recovers. It gets light only from the 20k bulb, shaded from the 10k. I cant imagine this is too much light, the tank is two feet deep and it doesn't expand to the point that makes me think its reaching for light. It gets just enough current to gently move the flesh now and again. I am adding iodide daily. Should I increase flow, lighting...anything? <>> My water seems fine, I am back to weekly 5 to ten gallon water changes. I use instant ocean aged for at least two or three days. Only R.O. water is used for mixing salt and my top off unit. The top off water is buffered before use. Another question! I have not noticed much growth in my coral over the past year. I feed my refugium weekly with some flakes or scraps from the food cuttings for the brain. It is full of little white stars and Amphi/cope pods! I have baby snails (Margarita) coming out of my...and there is good Coralline growth. Is there a need to house a small fish or two for nutrients or something? <> Other than the feeding the fuge and the brain, I add no other foods. <> I do not get it! I have noticed that when I turn my Chaeto over and the tank clouds up a little, that the little hard tubes on my live rock shoot out what look to be old dusty spider webs. It makes me want to stick a feather duster in there and clean it out! I think I know the answer, but just to be safe, could these little guys irritate my coral? <> I really appreciate your role in this hobby, you are all a great source of help! <> Thank you! Rob <>

T5 or Halide 2/15/08 Good day, Rogie here. <Hello, Scott V. with you today.> I'm in the middle of planning my 90gal SW tank. The tank will housed my current corals (zoas, mushrooms, LPS and few SPS) and will be adding more SPS in the future. <OK> My problem is on the lighting. I can't decide which type of lighting will suit my coral needs. I am being torn between 2x250W MH (14k and with moonlights) or 48' 6x54W T5 HO. I have been doing my research reading posts/threads at different forums and the more I read, the more I become confused on which to get. To settle this dilemma, I need your professional advice. <This has been a growing controversy over the last few years. The fact of the matter is that either will work, although if you go the T5 route you will likely need 8-10 bulbs to get the same intensity as the halides you propose. I personally like and use halides (primarily because of the shimmer effect they provide) over the T5, but others are just the opposite. You can have a very successful tank with either. Do keep in mind that you may need a chiller with the halides, although there is no guarantee you won't anyway. > Thank you in advance and more power. <Welcome and thank you Rogie. I am sorry I could not be of more help here. This comes down purely to personal choice, you must decide. Have fun, Scott V.>

MH Lighting'¦Color Temperature and Photoperiod -- 11/24/07 Hello Wet Web Crew! <<Hi there Melinda!>> I recently purchased a used metal halide lighting system and a 60 gallon acrylic tank from someone leaving the hobby. <<Neat!>> It's my first experience with metal halides and I'm excited to finally be able to keep some sps and LPS corals. <<Mmm, can be kept with other lighting as well'¦but must confess my preference is MH for most ALL marine systems>> I'd like to stock with some of my favorite softies too. <<Like a challenge, eh?>> I know mixed tanks require a great deal of filtration and carbon... here's my first speed bump: I have just installed a 30 gallon DIY sump with Ecosystem Mud and bioballs (I can't WAIT to see how it works!!). Ecosystems site does not recommend using activated carbon for continuous periods of time'¦what do you suggest? <<I've not used the Ecosystem methodology'¦but with the aggression and allelopathy present in this small mixed system I do think some form of chemical filtration should be present. Perhaps Poly-Filter would be a better alternative here>> If I should use the carbon, can I just put it underneath the bioballs? <<It is better if placed in a canister filter or dedicated reactor to 'force' water through it'¦but yes, it can also be utilized as you mentioned>> Will this be sufficient filtration for a mixed tank? <<If in sufficient quantity (a cup or two) and changed out frequently (bi-weekly)>> My next issue is the lighting. The fixture is from Hamilton Technology and has 2 175-watt metal halide bulbs and 2 40-watt fluorescents. <<Should be more than ample for this tank>> He has it set up with a white MH bulb and a Blue MH bulb. The fluorescents are 1 blue and one white as well. I wanted to set up a dawn and dusk cycle so I was hoping to use the 2 10000K white Metal halides for 8 hours a day and the two 40 watt fluorescents with blue bulbs for 12 hours. <<This is fine, but I recommend 'at least' a 10 hour photoperiod for the halides, with twelve being preferred (adjust the fluorescents accordingly)'¦to more closely mimic lighting in the tropics>> Will this be sufficient lighting for my plans or would you recommend something else entirely? <<As stated>> I hope you understood that... I confused myself! <<Ha'¦no worries!>> Thanks for your help! Melinda <<Happy to assist. EricR>>

Re: Limited MH Lighting Options Available...What's Best For 43' Deep Reef? -- 11/14/07 Hi Eric, <<Hello Marc>> Thanks for the detailed reply. <<Hope it was useful>> The MH bulbs I currently use are branded "Micron" and they appear to be intended for commercial/industrial use, rather than aquatic. <<This is not 'all bad.' Many 'Hobby' products started out as/have been adapted from 'commercial' gear>> A take what you can get situation I assume, as I did not purchase these bulbs myself but rather my previous aquarium supplier. <<I see>> I believe this is also why my rating of 25,000K does not appear very blue ... <<Hmm, yes...possibly a guessed-at or made-up rating even...or maybe these bulbs are VERY old>> likely this bulb has a very low CRI; similar to the cheap bulbs you see on eBay with CRI around 60. <<Another possibility, yes>> I will also check my ballasts as I believe the entire MH setup is of commercial/industrial intention. <<Even so, these should be fine...though some bulb brands may work better with than others...depending...>> I am thinking now of going with 4 x 400w 10,000k XM, Iwasaki or similar bulbs; <<If you can get them, Ushio gets my 'preferred' vote for this Kelvin temperature. You can get them online here for $70.00 apiece (http://www.businesslights.com/ushio-400w-10000k-mogul-base-metal-halide-lamp-p-853.html)...though I don't know if the shipping will kill you. I don't think Iwasaki offers a 10000K bulb (at least not here in the states), but if the XM bulb is all you can get that will be fine too>> then supplementing with some actinic fluorescents, as you recommended. <<Okay>> With the adjustment to the duration of the MH, this should also reduce my electricity consumption I expect. <<Mmm...do still plan on a MH photoperiod of at least 10-hours (12-hours is better, in my opinion) per day>> Do you think this would be a good route to go? <<Does sound 'like a plan'>> By the way, am living in Thailand. <<Ah! Quite a large 'Freshwater' ornamental fish industry over there, I believe...not so much geared toward 'marines?'>> Thanks again! Marc <<Always welcome. EricR>> Mixed Reef'¦Metal Halides, Too Much Light? -- 09/09/07 Hello there. <<Howdy Justin>> I have a 75 gallon reef with softies and LPS. It has been running under 260W of PC. I have been interested in upgrading to a 120 gallon tank and keeping a few clams. <<I see>> My interest peeked when I recently came across a free MH retrofit kit (2-250 HQI). <<Free? '¦Neat!>> I jumped at the opportunity and eagerly placed the system over my current set-up. <<Mmm, and acclimating your livestock to the new/increased lighting'¦hopefully>> I acclimated using your site's suggested screen method to my best understanding of the procedure. <<Ah'¦good>> It has been about 2 months since the first full lighting day and many of my corals (bubble, star polyps, and candy cane) have not returned to their previous glory. <<Hmm'¦are possibly receiving much more light than they need/want>> Is this lighting ever going to work for these or other soft and LPS type corals (even in the 120 perhaps)? <<Increased distance/water depth between the malaffected corals and the lights may well help/make a difference>> Or would you suggest one of the following: 1. Give up the softies <<Not necessary'¦but you do need to find them a 'place' in the system where they are 'comfortable'>> 2. Go back to PC. Keeping in mind that there are plans for a 120 gallon upgrade. <<Again, not necessary...with some attention to where the corals are placed in relation to the lighting>> Sorry about the long story, but I have become indecisive and need guidance in making this tough but crucial decision for my reef. <<Metal halide is my preferred lighting source for most any marine system'¦better aesthetics, greater flexibility, more bang for the buck'¦in my humble opinion. A few things you can do here are'¦ increase the height of the lights above the water'¦ move the more sensitive/less light requiring species to the bottom of the tank'¦ increase the Kelvin temperature of the bulbs. Any/all of these will reduce the Photosynthetically Available Radiation <PAR> reaching the corals>> Thanks for sharing your knowledge and experience with a fellow hobbyist. <<Happy to assist. EricR>>

Re: Reef Tank Lighting 7/27/07, MH, HQI diff.s Hi Salty Dog, <Hello Mark> You stated... "The 150 watt is a HQI system, not a MH" I thought both the 150W and 175W were Metal Halide systems. <They are very similar in lighting intensity but the HQI (High Quartz Iodide Lamp) runs on a different type ballast than the MH.> What is the difference between the HQI and MH? If they are different, what are each ones advantages and disadvantages? <Well for one, the HQI systems are more compact, smaller lamps, smaller ballasts. Some say the lamps last longer and hold the K value for a longer period. The MH systems are a little cheaper to get into, and much more is offered for the DIY person. As far as heat, they both produce about the same, watt for watt. The advantage I like about MH is that lamps choices, both by Kelvin rating and manufacturer, are more abundant. Depending on manufacturer, lamp prices run about the same for the 150HQI and 175 MH. For the money, you are getting a little more light with MH. Do Google, there is much info out there on reef lighting.> Thanks, <You're welcome. James (Salty Dog)> Mark

Glass lid needed with metal halide?  -- 07/26/07 I've found so much information searching on your FAQS on the web. <excellent> I wasn't able to find a answer with the same equipment as in my tank. I ordered a Sun Pod 2x250w 14k MH fixture for my 90 gallon reef and it will be mounted 12 inches above my glass lid. Since I plan to keep SPS corals in my aquarium, will I need to remove my glass lid in order to give enough light to the corals? <The glass lid will, to some extent, decrease the amount of light getting to your corals. But how much light it will impede depends a lot on how clean and dry you keep it. Lids have a way of getting wet, salty, and/or dirty pretty fast.> As for the heat issue, I have a chiller set at 76 degrees. <You'll definitely need that chiller with the glass lids and metal halides.> Which can be adjusted as needed when the fixture arrives so I don't think I would need to remove the glass lid for the heat issue. If you guys/gals think I should remove my glass lid, I'm very worried about my fish jumping out. Any way to prevent this? <Since you have a chiller, the only concerns left with the lids are going to be of gas exchange and the lids getting wet, salt, and/or dirty. If you can manage to get good aeration even with the lids, and if you can keep the lids clean and dry, then you should be ok. But if all that becomes too difficult, there are a few other ways of keeping fish from jumping out. If the fish aren't really small, eggcrate should work. If not eggcrate, there are other similar type plastic grates you can get at hardware stores that might work.> Thanks so much again for all of your support! <No problem> Peter <Best, Sara>

Shallow Tanks and Metal Halide  7/20/07 Hi crew, my tank is a square shallow tank and there is a question that has been bothering me. The dimensions are 20X20X8 (LxWxH) and there is a metal halide over it. I've read that metal halide bulbs lose their intensity and eventually the strength to penetrate deeper into tanks (therefore needs replacing about ever 6-9 months). This leads to my question, since my tank is shallow, will metal halide bulbs last longer with the tank? The light penetration should be greater right? Thanks for the help. <The bulb will still lose its intensity at the same rate. However, with a more shallow tank, you probably don't need the bulb to be a full intensity. It might be plenty of light even after 9+ months. However, you might be concerned about the change in lighting over time. If you'd rather keep the light intensity more stable as the bulb ages, you could start new bulbs up higher over the tank and lower it as the bulb gets older. But of course, bulbs vary quite a bit from brand to brand and even from bulb to bulb sometimes. So the only way to really know for sure what's happening with your bulb is to measure the bulb's output with a par or lux meter. Best, Sara>

Metal Halide Photoperiod 7/10/07 Hi crew! <Hi Pete> Thanks so much for all the wonderful info on your site. <Thank you!> I have a couple questions on metal halide lighting. I have a 90 gallon FOWLR soon to be a mixed reef. I am planning on upgrading to a 48" Outer Orbit 2x250wMH/2x54T-5 lighting system. It says it comes with 2 electronic timers. The future corals I have been planning to get are: Acros, Pocillopora, torches, zoos and some polyps. Knowing the corals I plan on getting. what do u guys think the ideal photo period on the MH and the T-5 should be? Any ideas would be great. <First, you will need to slowly ramp up to the desired photoperiod. I would start with one hour and increase an hour every day. For starters, try and 8 hour photoperiod on the MH's and 10 hours on the T-5's. After a couple of weeks, see how the corals are reacting. You may have to increase the MH time by an hour or two. Personally speaking, with twin 250's, the T-5's are overkill on your 90 gallon tank. Using 14K lamps will produce an attractive blue tint to the water, and actinics would not be necessary. James (Salty Dog)> Peter Choo

Re: Metal Halide Photoperiod 7/11/07 Thanks for the wonderful fast reply James. So...twin 250's maybe a bit to strong for 90 gallons? <Is not what I said, I said the T5's would be overkill with two, 250 watt halide lamps. I'm assuming you have a 90 tall and the 250's alone would be more than adequate, and great for keeping clams, monti's, etc.> Would a Outer Orbit 48" 2x150w MH/4x54w T-5 be more appropriate? <Would be fine but the light loving creatures such as clams, acros, etc., would have to be placed in the upper third of the tank.> If not, could you kindly recommend a MH for my tank? Preferably a fixture with a mounting leg. <What you are considering is fine. My personal opinion is that hood systems are pretty expensive for what you are getting. What you are looking at is probably in the $700 range or higher. I prefer using a wood canopy with retro kits. I've just ordered two 175 watt, 14K retros with excellent PFO ballasts, quick disconnect cords, and very nice reflectors for just a little over $400.00. Supplemental actinics aren't really necessary when using 14K lamps or higher. Try a Google search for MH aquarium lighting and see if you can't find a system that just uses MH lamps, preferably twin 175's or 250's. James (Salty Dog)> -Pete Is Metal Halide Lighting Harmful To My Health? - 06/27/07 Hi!!! <<Hello!!!>> Hope you can answer my question today. <<Let's see then...>> Is being exposed to metal halide lighting bad? <<Mmm, wish I knew what your definition of "exposed" was here...but generally speaking keeping "direct" exposure to a minimum is a good practice>> Is there any negative effects on health? <<I would think any health risks would be very similar to those associated with too much exposure to the Sun>> Anything I should be worried about? <<Do take steps to shield your eyes/your families eyes from direct exposure by using proper lamp housings/fixtures and avoid looking directly at a burning bulb...the occasional/accidental glance is not going to permanently "blind" you in my experience, but it will "dazzle" you a bit...again, much like looking at the Sun. I don't think you need to be "afraid" of metal halide lighting, but it is a very intense light source that produces varying amounts of Ultra-Violet radiation that does indeed require your respect>> Thank you! <<Happy to proffer my non-medical opinion...I hope it helps. Eric Russell>> Lighting; MH and T5 - 02/07/2007 Hi Adam, <Hey Gin Josh.> Thank you for the fast response. <We try our best.> I probably would be looking at going for a shallow water bio-tope. If I went with the 175 or 250W pendant, how high above the tank should it be hung? <Mmm...depending on how bad/good your heating problems are about 12"+...at least 8"...you don't want to cook your animals.> I would be interested in the "more reputable models/brands out there" that you mentioned. <Mmm...Sure I will list a few: Hamilton, Giesseman, PFO, Sunlight Supply (Just a personal plug I love the simplicity and effectiveness of the S.S. pendants)....> Yes fluorescents would be tough on this but I may ask, What about T5/HO instead of metal halide? <Ummm, I think they are different types of lighting for different types of applications but without going into too much detail...I am a huge fan of T-5's, great bulb life, very efficient when paired with the proper reflector.> Thanks again. <No prob.> Josh Rosenberg <Adam J.>

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>>

Re: MH Upgrade...Options/Considerations - 01/18/07  1/25/07 Another quick question........ <<Ok>> I have decided to go with 2 HQI MH bulbs.  I want to know how high I should put them in a hood, and what wattage, (2) 250 Watt or (2) 175Watt I should have for a 60" wide tank and 23" high.  Please help. <<If by "HQI" you are referring to the "double-ended" style of bulb (as most hobbyists do) then your options here are 250w and 150w.  As stated in my previous reply, the lower wattage bulbs (either 150w or 175w) would be quite adequate, but my personal preference would be the 250w halides for greater flexibility re species selection/placement of the SPS corals, and due to the need to mount the lamps high enough to get an adequate "spread of light" with only two lamps on this 5-foot long tank...which means the lamps will likely need to be mounted ten or more inches from the water's surface.  If this is not possible, then six- to eight-inches is fine...placing less light-demanding species at the outer margins of the lighting spread.  Whatever you do, be sure to plan/allow for the extra heat build-up in the hood from the installation/use of these HID bulbs>> Thanks, Jeromy <<Regards, EricR>>

Re: Obsessing Over Lighting (And More) - 11/26/06 Hi Eric, <<Hello Ken>> I think you banged it into my head enough; I'm sticking with what I have. <<Finally! <grin> >> I am going to switch out the MH 10,000k though to the 14,000k Phoenix.  I had heard good things about these. <<Hmm...maybe I'll give them a try too...>> By the way, I have finally gotten some algae.  Not really so much in the way of diatoms (yet?). <<May have come and gone already>> I have gotten some greening algae tint to some of the rocks, particularly the ones at the highest point in the tank.  Some people have told me that I should not have put any fish or hardy corals in the tank yet until I had my "clean up crew" but that didn't make that much sense to me either. <<Well Ken, ideally you would have left the tank "un-stocked" for the first 6-12 months (my tank was up for more than 7 months before I introduced the first fish).  This gives the populations of micro- and macro-biota that came on the rock time to establish sustainable colonies ahead of the introduction of large predators (very important for those aquarists wanting to keep Synchiropus species...assuming the tank is adequately sized/configured to start with).  Most hobbyists find it difficult to wait, and once the fish go in, adding some coral will help compete for the nutrients feeding the alga.  As for a "clean up crew"...my feeling is these are of small utility, even deleterious in many instances (tend to scrub the rock clean of emergent life), and are pushed so hard because they are very profitable to those selling them.  Better to rely on proper quarantine/stocking/husbandry/maintenance to keep your tank healthy and looking good>> The tank had cycled for sure, and I needed to get some life in there (ammonia source). <<Was never a "rush">> Even after adding two tangs, I tested my water for ammonia and nitrites for a few days afterwards and never got anything above zero.  By the way, my nitrates now are at 2 ppm, and phosphates are below the first color block on the Salifert kit. <<All good>> I did go out and buy the Two Little Fishies Phosban reactor and some ROWAphos.  I heard good things about this. <<Me too...as well as bad things.  I would use the ROWAphos sparingly/only as needed if detectable levels become a problem.  Scrubbing too much phosphate from the system can create its own problems...all life requires "some" phosphate>> I did go out yesterday and buy 20 scarlet-legged hermit crabs. <<I am not a fan of hermit crabs...much too "opportunistic" in their feeding habits>> What else should I get in terms of crabs and snails?  Should I also get more of the ones I have as well? <<Mmm, I don't know what you "have" but as stated, "I" would not add crabs at all.  Where snails are concerned, they too can be destructive/opportunistic, but I do like to keep Nassarius and Cerith species as detritivores and as bioturbators of the substrate>> I put my Ca reactor back on Thursday night as my Ca hit 8dKH.  I know that is normal range but I wanted to keep it closer to 10-11. Last night I was at 11 dKH so I turned off the CO2.  I guess at some point when the tank is stocked more heavily with corals that I will hit a balance and I can leave the Ca reactor on.  My feeling is that I will always have to switch it on and off.  What is your opinion? <<Maybe, maybe not...but you might want to take that money you were going to spend on new lighting and invest in a "controller">> I still am looking to get a Kalkwasser reactor or stirrer for top off though.  Even though my pH is in the acceptable range 8.00 - 8.15 generally, I would like to raise it. <<I see>> By the way, my pH got to 8.23 Thursday night before I put on the C02 for the Ca reactor. <<Telling...again>> That's the highest it has been to date.  Also, my ORP got to 321 which is the first time it ever got that high.  It has been in the low to mid 200's.  I don't know if that is a function of a new cycled tank and not a lot of animals, or is it my possible CO2 issue. <<Much can affect ORP (dissolved organics, pH, etc.), have a look here: http://www.wetwebmedia.com/redox.htm >> I did calibrate the ORP probe and it reads like it should in the two solutions with the quinhydrone (if I spelled correctly). <<It is>> Take care. Regards, Ken <<Cheers mate.  EricR>>

HQI Lighting Approach  11/01/06 Hello. <Hi there! Scott F. here today!> I sent a message about 3 days ago but maybe you guys haven't had a chance to read it. <Sorry- we usually try to get to 'em fast...We've been a bit inundated lately; sorry about that!> Anyway, in case the message didn't get to you I thought I would send it again. I have a 21 inch tall 55 gal tank with about 2.5 inches of sand in it. The tank is 4 feet long and 18 inches wide. I have recently purchased 2 150watt double ended metal halide HQI pendants. I can either use 14K or 20K bulbs since I purchased 2 of both. I would like to be able to grow anything I choose in the tank and do not really want to have any constraints in regards to inadequate lighting. I realize there are incompatibilities between certain species and other constraints other than lighting. I am interested in housing a clam and have heard they are one of the higher light demanding species. Can my lighting set up support a clam? <I believe that it can, particularly if you place the clam in the upper third of the aquarium (i.e.; up on rockwork). I would use the 14,000k bulb, or consider a 10,000k bulb, as the color temperature and PAR value of these bulbs is a bit more appropriate for clams.> If this lighting is not adequate for all animals please tell me what would be. Also how high do you suggest I hang the pendants above the water surface. <Depending on the brand and model of pendants that you're using, you can either hang them from ceiling mounts or suspend them in a canopy..> Do you think this lighting may be too intense for lower light zoanthids and mushrooms? <Not if they are adapted to the light, and if they are placed lower down in the tank. I have no real concerns about them being harmed unless they are right under (mere inches) from the light source.> Thanks for your help in advance. Marcin. <MY pleasure! Regards, Scott F.>

Lighting Question 10/14/06 I just upgraded from 2x65 watt compact to a 150 watt MH. How long should I leave the lights on day while everything acclimates? <I would start at 4 hours and work your way up> I have mushrooms, Ricordeas and leathers. I can't hang the light above the tank so it sits on top of the canopy with an opening at 8 inches above the water. Thank you Debra <Monitor your corals health and slowly increase the photoperiod every week until you reach your target.  Cheers! -- Dr. J>

Some Light Conversation- Part II   10/4/06 Hi Scott, <Hello again!> Thanks for your quick reply. I'm glad I asked you the question as I figured I was on the borderline of 150 and 250 watt MH's. <Yep- 24" is at the "decision depth", as I like to call it, where you may be better off going with 250 watt bulbs if you're keeping light-demanding invertebrates.> It seems that the two lamp 250 watt HQI systems only come with two 54 watt T5 bulbs incorporated with them. This would make then make it (500 MH total watts plus 108 T5 total watts). So you are saying that this will cover my needs for the anemone, soft and LPS corals. Would this be enough light for clams as well? <In this dept of setup, I believe it will.> You had mentioned the importance of a good quality reflector, is there a way for me to find out if the unit has good quality reflectors if I am purchasing over the internet? I have heard of the name Reef Optix for reflectors. Have you heard anything about these. <Absolutely. I have used a number of them over the years, and they are one of the best reflectors out there, IMO. Sunlight Supply (the manufacturer) makes a few different reflectors; I favor double ended halides, so the "Reef Optix III" or the "Lumenmax" reflectors do a great job, IMO.> I had seen it with a unit with the name Maristar and the manufacturer of the lighting system is Sunlight Supply. Do you have any thoughts on this? <Excellent units/company. Also check out Aquamedic and Geissmann for quality lighting systems.> Lastly, is hanging a unit or putting it on legs better one way or the other? <Personal preference and aesthetics come into play here...Also, you want to consider ease of access into your system. I like the idea of hanging it over the tank- 6-10 inches or so off the water.> If it is hung, how high off the tank would be recommended for my 24" depth tank. I was also wondering if hanging could be beneficial when adding new corals as I could raise the height of the fixture to lessen the intensity, and then lower it after the acclimation period. <Yep!> Lastly, I don't know your policy on recommending equipment, so you can delete this portion if you need to if you post this on your website. <We are not on anyone's payroll, so to speak, so we can make recommendations based upon our personal experiences and opinions.> Have you heard good things about the Aqua Medic HQI/T5 systems in terms of workmanship and their reflectors? I was going to go with this or the Maristar that I mentioned above. <Funny- as above, an excellent product, too.> Thanks again so much. Regards, Ken <My pleasure, Ken. I don't think you can go wrong with any of the products discussed above! Good luck! Regards, Scott F.> Which Lighting Solution? - 09/14/06 If I were to make another investment in this tank should I invest in power compacts, T5's or another type of halide. <<I prefer metal halide lighting for most any/all marine systems.  Is a great look, and can usually be positioned/Kelvin temperature adjusted to suit most any biotope>> There are two anemones, the original one split, all others are soft corals like mushroom' and leathers. <<Firstly, this is an unnatural mix, thus making it difficult to provide suitable lighting.  But with the presence of the anemones...metal halide lighting most definitely, in my opinion>> The fish include two perculas and a golden angel.  Cost to run and purchase is a concern, Thanks Ron. <<Doesn't cost any more to run 300 watts of metal halide lighting than it does to run 300 watts of fluorescent lighting...and the metal halide bulbs have a longer useful lifespan.  Regards, EricR>> Re: Which Lighting Solution? - 09/15/06 So would another Coralife 150 watt tank-mount be a good investment to supplement the one that I already have? <<If you're happy with it...sure.  EricR>>

Lighting Confusion  9/9/06 Dear Bob et al., <Jim> I have read most of the articles on WWM media re: lighting many times over the years, and have appreciated the improved understanding I have gained.  But I am increasingly one thing.  Bob, in your article Marine Lighting: Quality, Quantity and Duration, you encourage the use of fluorescents, even normal output fluorescents, in reefkeeping. <Mmm, yes... in part these are "old" (more than a decade) statements/articles... and in part I am a big/ger fan of this technology for most folks... as we'll discuss further here>   You list HO, VHO and PC as higher cost, and in some ways less desirable solutions, and you put MH's under the category of 'losing' technologies, because of their high cost, the massive heat problems, and the fact that they are actually too intense for many life forms. <Mmmm... thank you for this... opportunity, prompting... I would not label MH as "losing technology" per se... but inferior for many settings (tanks shallower than a foot and a half in actual water depth, most organism mixes... but/and most importantly ones/systems that don't have matched capacities for providing adequate biomineral, other rate-limiting aspects... boosted light/intensity alone is not a panacea> Based on this and much other reading and input, I chose to go with 4x110W VHO's for my 72G reef, which by your article exceeds the 1-2w/gallon you recommend, and it has worked great for the few soft corals and several LPS corals I have kept: Euphyllids, Caulastrea, Turbinaria, Favites, Trachyphyllia, and Lobophyllia (not sure I spelled those right). <Close enough. Will fix before posting> In fact, I had to move the Favites DOWN after it started to bleach and pull in when I put it high on the rock wall.  Last year, I wanted to purchase a crocea clam, but was angrily told by several reefkeepers I would just be killing a helpless animal by trying to keep it under these woefully inadequate lighting conditions.  I wrote in to WWM, and was reassuringly told "not to believe the hype" and that, given the correct water parameters, a crocea could live quite happily under VHO's, if kept within one foot of the surface.  My first clam died shortly after purchase (too quickly to be lighting, I believe) but my second crocea has been alive and doing well for six months.  It has grown, albeit slowly, putting on about a quarter inch of new shell in those 6 months.  Okay, now to the question: My 72G reef recently blew out a seam, and I am quickly upgrading to a 150XH.  I chose the 150XH, despite the fact that some have expressed concern about the undesirability of deep reef tanks, for two reasons: space limitations within the house (six feet long just won't fit), and the fact that my lighting is all set up for a four foot tank.  But the concern has been raised that my 440W of VHO will truly not get the job done on a tank that deep.  So I started reading again, and I noticed that, despite everything your article said about MH being a 'losing' technology, you seem to recommend them fairly often in your FAQ's.  For example, a recent post: Dear Bob, My present tank is 60"L x 24" W x 30" H housing only softies due to angels and BF's lit by 6 x 40W NO fluorescents. <Okay> I have two options of light upgrade, 2 x 150W MH or 8 x 55W PC. Taking into consideration that I do not plan to have SPS, which would be a better option. <A tough one here... both could be made to work. I will opt for the metal halides here though... due to the size, shape of tank, my personal "looks" preferences. Will be spectacular. Bob Fenner> Regards. This seems like a complete turnaround from your earlier position! <Mmm... perhaps... is mostly a change due to tank sizes (getting larger, deeper) and improved "other" technology, and its popularity> (I am not trying to be accusatory, I am trying to understand.)  Is this recommendation because of the deeper than "normal" tank listed by the author of the question, or has you opinion on the usefulness/value of MH changed considerably since you wrote the article I mentioned, or is there some other consideration I am missing? <Is mostly the former, a bit the latter>   I have zero desire to spend lots of unnecessary money on lighting, or worse yet, a chiller.  But I also don't want to do my animals a disservice.  I don't mind relatively slow growth (in fact, I prefer it.  I have had to frag my Euphylliids and sell/trade the pieces about eight times in the last four years because they got too big and started stinging each other, and that was only under VHO's).  But I don't want to starve them for light. <Mmm, let me try to make a point this way. Your Euphylliids are receiving much more photonic energy than they would in the wild... can/could be metabolically boosted further still with more light and concurrent other conditions... is this "worth it?"... to frag more often? The added risk should the power fail once your animals are "boosted lighting" photo-adapted, the cost of energy consumption? Not an easy "yes/no" question...> In my new 150XH, I am willing to keep most of the corals relatively higher up on the rock structure, though a few, like my very large (8-9" dia), seven year old bright pink rose Trach will still need to go on the bottom.  I have no intention of beginning to keep SPS anytime soon.  Will the VHO's serve? <Could... but to proffer a more "complete" response, if this were your starting tank, and you were/are of the apparent level of sophistication as you appear... I would likely start with MH... two 250w pendants likely> Would they serve if I added a few more VHO's/PC's?  Or, given the depth of the tank, had I better consider MH's? <This last> If so, what wattage?  I am really not excited about the idea of two 400W MH's in my living room. <Me neither... would need a chiller and a basket of sunglasses to issue to visitors and family> Would two 150W DE's fit the bill, or do I need to go with 250W's?  A little clarification please! <The 150's would "get you" about what your present fluorescents do (though look a bit nicer)... IF you're switching to MH... I'd go with two 250's> Very confused, but sincerely grateful for your help, Jim Jensen <Thank you for the opportunity to make myself clearer. BobF, visiting in Jamaica> PC or MH? - 09/05/06 Hi, <<Hello>> I am confused about what type of lighting system I should go with. <<Whichever best suits the species of animals you plan to keep>> I have looked around your site and I'm still a little confused... <<Did you look here? http://www.wetwebmedia.com/marlgtganthony.htm    and here? http://www.wetwebmedia.com/marine/setup/lighting/index.htm >>   I plan on having soft coral in my 75, tree corals, and some zoos and possibly a brain coral....  I'm not entirely sure if I should go with power compact or metal halide with VHO... Thanks. Adam <<Either choice will suffice.  The power compacts would likely be cheaper to purchase, but the metal halides give more bang for the buck in my opinion.  A pair of 150w or 175w MH fixtures with bulbs in the 10000K-14000k range should do nicely.  EricR>>

Re: PC or MH? - 09/07/06 Thank you for your advice... <<My pleasure to share>> I have one last question...  If I went with 2 150w HQI bulbs at the 14k range, would I be able to leave those on for 8 hrs? <<Mmm, I recommend you leave them on for 12-13 hours per day as this more closely replicates the daytime photo-period in the tropics where your tank inhabitants are/will be collected>> Thanks again, Adam Dusza <<Always happy to assist.  Eric Russell>>

90 gallon Reef MH question, heat   9/5/06 Bob,     I have read a lot of your articles on WWM about the  Metal Halides and everything else.  I currently have a 90 gallon all glass  aquarium with a corner overflow.  I'm currently using a Aqualight Plus  Fixture contain 2 10k whites and 2 actinics all being 96 watts with the standard  wooden canopy above the lighting and the tank.  The tank without the use of  a heater stays around 77-78 degrees.  I'm playing with the idea of getting  the New Outer Orbit lighting system that contains 2 150w 10k  HQI MH and 2  130 watt PC Actinics.  With the tank being a taller tank and liking the  shimmering effect of the MH i wanted to know if there was a way to include the  canopy at least on the outside without worrying about the heat issue. <Fans... a chiller...> I  don't mind having an open top canopy but i would like to at least have some type  of a canopy so that i don't see the light fixture.  I was thinking about  installing two fans in the back on the canopy to blow the air out from under the  lights as well as drilling some holes on the outside of the canopy to allow air  flow thru the fixture itself that does contain an 3.5 inch fan always. <Better to blow in and out...>   I  just don't really like the fact going somewhere and seeing the lighting fixture  and the light peeking thru the sides between the light and the top of the  canopy, but i do understand that MH put out a lot of heat but i wasn't sure if  these HQI lights with the new design of ballast put out else heat.  But my  main issues is being able to put the light system on the tank without it being  too much light for the corals, LPS, Calms, SPS and zoos and polyps. <Won't be here>   And  having some type of a canopy around the sides so the tank looks complete like a  piece of furniture not just a tank please let me know Thank you Drew <Can be done... will likely need a chiller. Bob Fenner>

Re: 90 gallon Reef MH question.  9/6/06 With the MH being about 7 to 8 inches off of the water is this ok, or is it going to cause the light to be too intense for the tank. <Need to elevate this high or higher for light distribution and safety reasons... see the manufacturer's recommendations re>   Do you believe that with fans I can keep it cool or more than likely i will have to have a chiller, which i really don't want to purchase at all. Drew <More than likely the chiller will be needed if using 250 watt units or higher. Bob Fenner>

T5 or MH, Heat Issue...   9/2/06 Hello Crew,     I'm upgrading my 100 gallon tank into a reef tank. Currently I'm planning on removing my closed canopy and replacing it with an open lighting fixture. I've set my mind on either Metal Halide or HO fluorescent T5 lighting.     The thing is, I don't know which lighting will be better for my setup. My tank dimensions are 58" wide and 18" deep. I would like to keep Bubble-Tipped Anemones and Tridacnid Clams (I would place the clam at the bottom of the tank). My preference in Corals is still not clear, but I would like to be open to a wide range of possibilities.     I've read through your FAQs that Clams prefer MH (and so do I, due to the pleasing shimmering effect), but heat is an issue to me. My room temperature is 25 C, but my tank is around 27 C and I think it's mainly due to the trapped heat in the closed canopy (with three 40 watt fluorescent lamps, will remove soon). I'm also adding more powerful powerheads that will add up to the heat. I'm not sure if T5's will provide enough lighting for the intended inhabitants while emitting low heat, and need your inquiry. Thank you. Have a nice day. Mohammad <<Mohammad:  While there are some people who like T5's the vast majority of people that have anemones and clams (including me) have MH lighting.  If your canopy is open, I don't thing the MH lighting will significantly increase your temperature.  Some day, we may be able to light our tanks with LED's; but, the technology is still being tested.  Best of luck, Roy>> Metal Halide Addition... Impulse Buying - 08/30/06 Hi, <<Hello!>> Looking for a quick opinion. <<I'm sure I have one>> I currently have a 75 gallon FOWLR tank (48x18x21).  I have an Aqualight that has 4x65w PC bulbs (2 actinics, 2 10000k).  I want to start adding some corals and such so I want a complimentary MH for my PC lighting. <<Mmm...have you researched/determined the corals you are adding will require this type/additional lighting?>> I basically don't want to be limited by my light if I'm in a fish store and something that catches my eye. <<Please do research your purchases "beforehand" to determine if you can provide for its needs and to ascertain its suitability for aquarium (your aquarium) life...impulse buying usually lands both you and your livestock in trouble>> I'm wondering if I should go 175w or 250w and what Kelvin degrees you recommend. <<For your tank size/depth, two 175w 10000K MH bulbs will be plenty>> I'm leaning towards a 250w pendant but not sure if I want 10000k, 14000k, or 20000k bulb. <<The pendant is doable if you want to spend the extra money (initial purchase and bulb replacement/electrical costs) as it can be easily adjusted for height, and the 10000K bulb is a good choice though this too is dependant on the species of coral you with to keep (deep water/lower light requiring organisms would appreciate the 20000K bulb)...no single lighting solution is suitable for everything that might "catch your eye"...is best to select/try to replicate and stock corals from a specific biotope or niche on the reef>> If I decided down the road to downsize to a 50gallon tank, would 250w be too much?? <<I've seen folks blast their 55 gallon tanks with 400w halides, but yes, in my opinion 150w or 175w is completely suitable.  I have an SPS dominated 375 gallon (30" deep) reef and my lighting consists of a combination of 175w (2ea.) and 250w (3ea.) metal halide lighting which provides me with great color and growth.  You don't have to "blast" your tank with light...water movement and proper feeding are big factors as well (and often ignored) to successfully keeping many coral species>> Thanks for all your help. Sara Kinnear <<I'm happy to assist.  Regards, Eric Russell>> Re: Metal Halide Addition...Impulse Buying - 08/30/06 Hi, <<Hello Sara>> Thanks for your help. <<Quite welcome>> I did not mention that I definitely want a blue carpet anemone for my pair of clowns and definitely will make sure all my purchases are researched. <<Then you'll likely find the anemone is not a good mix with a FOWLR system but best kept in a species specific display designed/fitted to its needs>> I just want to know that if I do the research and decide I definitely want to add "whatever" - I can and would not be limited by my lighting system. <<I understand Sara and I'm not here to give you a hard time, my purpose is to help you to succeed...do be aware that lighting is only a portion of the equation>> I am going to purchase a 175w system and use a 10,000k bulb.  Much thanks! <<Please read here and among the indices in blue: http://www.wetwebmedia.com/carpetanemones.htm >> Sara <<Regards, EricR>> HPS/Metal Halide Conversion Bulbs?   8/24/06 Howdy Folk, <Hi Zach> Love you books/website. <Thank you.> I have a 250 W HPS S50 ballast that I currently have a 4000K bulb in.  I want to get a higher Kelvin temperature for obvious reasons but the highest Kelvin conversion bulb I have been able to find online is an Ushio 250W 5200K 85 CRI Universal Metal Halide Conversion Lamp. Will this work or do I need a higher K value?  If I need a higher Kelvin value where can I find the bulb? <What exactly do you mean by a "conversion bulb"?  What are you converting?> Thank you, <You're welcome.  James (Salty Dog)> Zach Alexander Re: HPS/Metal Halide Conversion Bulbs?  - 08/26/06 I have a High Pressure Sodium Ballast with a Metal Halide "conversion bulb" in it that is only 4000 Kelvin.  I am not currently using this lighting system because I would like something around 6500K but the best "conversion bulb" I have been able to find is this one http://www.businesslights.com/product_info.php?products_id=1413.  Any suggestion?  And would the 5200K be okay or would I have algae problems.   <Ah, I see, not using a MH ballast.  The 5200 will be much better than the 4000 with very little yellow tint, if any.  Algae problems come more from nutrients in the water, the lighting just propels the process. James (Salty Dog)> Mercury Vapor Ballast Question   8/14/06 Ok I've been doing a lot of diy reading and can't seem to find a good answer to my question. I would like to have 2 MH of some type to go along with my 4 VHO's on my 55gal tank but have a small problem don't have the cash flow that some of the people in this hobby have. So I've been researching diy MH. I've found a few people speak of using a out door mercury vapor light that cost around 40 bucks not using the bulb that comes with it and using a 250w 65k Iwasakis bulb. Now how true is this? Can it be done? If this works I can just put 1 or 2 more actinic bulbs on my VHO set up to off set the color. Some help anyone, or a little insight to this please. I value your opinion always. <Some mercury vapor ballasts can run both, mercury vapor and metal halide bulbs.  You must be sure that the ballast itself is labeled, "For H39 or M59 bulbs".  These numbers are just an example, they will differ depending on the wattage of the fixture.  It is very unlikely that the 40 dollar outside mercury vapor fixture is going to have this type of ballast.  I would not recommend using a MH bulb with a "H" only type ballast.   James (Salty Dog)> Dez

Supplemental HQI Lighting On A 900 Gallon Tank   8/6/06 Salutations! <Hello Tim> I'm currently in the process of setting up a rather large aquarium, a 10' x 4' x 3' monster (3 feet deep). The tank is acrylic, and has 3 large 30" square cutouts on the top. My setup is as follows: 1) I live in Arizona in a house with a flat roof. 2) I installed 3 24" Solar tubes in the ceiling directly over the tank.  The tubes extend down to about 18-24" off the top of the tank, and don't precisely line up with the cutouts.  The two on the ends are slightly to the outer edge of the tank, and all three are more towards the back of the tank. (Joist placement issues) 3) The tank is in a dedicated room, (front of the tank is picture-frame style into the living room) so aesthetics of the fixtures is unimportant. 4) I plan to dedicate this tank primarily to shallow water SPS and clams. I suspect that the three solar tubes, while providing a huge amount of light and hopefully offsetting my electric bill, will not be enough light for this tank.  I also think that for aesthetic reasons, I will need some blue or actinic lights to offset the natural sunlight coloring. Along those lines, my current thinking is to add three 20,000K 400W HQI MH fixtures to the tank.  However, because of where the tubes are, these would be centered more towards the front 1.5 feet of the tank.  I'm concerned that alot of my light will go directly onto the sandbed and the living room out the front face.  I was thinking perhaps I could angle the fixtures towards the rear of the tank, but I'm not sure if this will cause a high loss of light through reflection off the water surface.   The other option would be to put 2 halides over the braces between the solar tubes, but I am concerned about the effect of the high intensity light being directed directly at an acrylic panel. I suspect I will end up mounting a fan on the wall blowing crosswise across the entire tank to keep the heat down.  Also, the room is air-conditioned. So: What kind of supplemental lighting would you recommend for this setup? How would you position the lamps? Is a 400W HQI too much power? Maybe some other combination?  I can always also run them for only a few hours each day to simulate a mid-day-sun. Any other thoughts on lighting this monster? <Tim, a few questions before I can proceed.  First, is the tank currently set up and running?  If so, are any SPS corals or clams in the system at present, and, how are they looking with just the solar tubes?  James (Salty Dog)> Tim  

Re: HQI Supplemental Lighting on 900 Gallon Tank...Mmm, How Many Solar Tubes Per Gallon?    8/7/06 > <Tim, a few questions before I can proceed.  First, is the tank currently set up and running?  If so, are any SPS corals or clams in the system at present, and, how are they looking with just the solar tubes?  James (Salty Dog)> No.  The system isn't up and running yet.  I'm just about to add live rock and begin the cycling process. As far as the lights.. I think my primary concern is not to over-power the corals.  I realize I may be in a bit of uncharted territory here.  I will say, that the tubes light up the whole living room through the tank, and the light rays seem to be fairly direct, as I get the ripple effect like a MH light would. But hey.  I'll have the most accurate moonlight system of anyone. <Tim, to be honest with you, I'd see how things go with just the tubes.  You may have enough light here along with eliminating heat problems from 400 watt lamps.  See if your investment works before spending more money.  Also, in future replies, please include/reply to previous correspondence.  James (Salty Dog)> Tim MH Not Lighting   7/28/06 Hey guys -- <And gals.> Love your site... now to the business.... We've been running a 75 gallon take for about 10 months now - we have a Coralife Aqualite elite lighting system with 2 175W Metal Halide bulbs on it along with the PCs - all of a sudden one of our metal halides started not lighting all the way - I figured since the bulb was about 8 months old, it might have died - so we went to our local store a picked up a new bulb - the new one does the same thing - the center gets semi-bright, but there is no output into the take... The other 175W bulb in the fixture is fine... any ideas as to what we can do to fix?? <Sounds like the ballast for that lamp is bad.  Igniter voltage more than likely too low.  Hopefully you have a one year warranty on the fixture. James (Salty Dog)> Thanks, Brian Re:  Metal Halide Not Lighting   7/28/06 Thanks for your prompt response -- <You're welcome.> We did find out that the ballast is bad - never thought about a warranty - but we will def look into it - I think that our other solution is to just upgrade the ballasts to 250W -- is that something that is easy to do?? can one just buy new ballasts and then put 250W bulbs in the fixture?? <The 175 watt MH fixtures were designed to dissipate heat for two 175 watt ballasts, and, I don't believe 250 watt ballasts would fit into the fixture. I'd check with the manufacturer.> Once again I want to tell you how much we appreciate your site, we are new to the hobby and got in very quickly - along with our 75g - we recently set up a 29g mini reef - which is doing amazing - just added two true Percs - While on this topic, I hope you don't mind if I as another question... On the 29g we are running another Coralife lighting system with 2 65W PC 50/50s -- we have about 60lbs of rock, some from our bigger tank to help spread the Coralline algae - the tank has cycled for about a month before we added the fish - so, now onto my question, we were wondering if you thought there was enough light in there to support a small anemone for the clowns, since they have appeared to have bonded already -- <A 29 gallon tank is too small for an anemone.  Water parameters can change too fast.> if you take the total size of the tank, we have about 4.3 Watts/gallon -- if you take into account the displacement of the rock, the Watts/gallon are significantly higher, <Rock displacement means nothing in regards to lighting.> probably close to 6Watts/gallon - I appreciate your assistance and once again think your site is an amazing source of info, and we never would have gotten as far as we did in the hobby without it... <Thank you for your kind comments.  James (Salty Dog)> Thanks again, Brian Matching MH Bulbs to Ballasts - 07/21/06 I bought 2 175W HQI DE 20k MH bulbs on eBay for $20 in a bulk box of mixed type MH bulbs.   <<175W double-end (DE) bulbs?  Are you sure?  I didn't think there was such a bulb...nor does a quick Google search find one...curious>> My questions: 1.)  Can I run them on the same ballast as the 175w SE bulbs or will I have to upgrade to different ballast.  One of my ballast is the Advance F-can (72C5581 N-P) ballast. <<I believe this is 150W ballast, is it not?  It will not run the 175W bulbs...DE or otherwise>> The other is DIY Advance ballast. <<Mmm, this tells me nothing...>>   2.)  Should I upgrade to one of the HQI ballast or just plug and play? <<If that is a possibility, then yes.  My favorites are the IceCap electronic ballasts.  Great product/customer service/warranty...in my opinion of course>> 3.)  Will a 150w HQI <<bulb>> be able to run on these type of ballast also? <<Are we talking about the F-can ballast again?  Maybe, though I think unlikely unless that model was specifically designed for such a bulb>> Thanks, Shaun Montgomery <<Regards, Eric Russell>>

Re: Matching MH Bulbs to Ballasts II - 07/21/06 Yes there are a couple of 175 DE bulbs on the market.  Aquatrade sells them with their MH fixtures here: http://www.aquatraders.com/index.asp?PageAction=VIEWCATS < http://www.aquatraders.com/index.asp?PageAction=VIEWCATS&Category=49> &Category=49 http://www.aquatraders.com/index.asp?PageAction=VIEWCATS < http://www.aquatraders.com/index.asp?PageAction=VIEWCATS&Category=24> &Category=24 < http://www.aquatraders.com/index.asp?PageAction=VIEWCATS&Category=49> <<Mmm, yes...have seen these (advertised) before now that you mention...>> Also what is the bulb type of 175 DE and 150 DE bulbs.  (EX. 175 SE are M57) <<Don't know/am aware the DE bulbs have a "type"...perhaps if you contact the manufacturer re...>> Can I build a DIY house for the double ended bulbs and just buy the UV glass? <<Sure>> Or do I have to buy the full reflector. <<Nope, you can find/buy the UV glass online.  Some brand names are Optivex, UVILEX 390, and OptiClear...likely others can be found with a Google search re "UV Filter Glass">> Thanks, Shaun Montgomery <<Regards, EricR>> Lighting Question... extending wiring on/for MHs (Salty!)  7/14/06 Good day fine people!   <And to you> Once again I turn to you for a little expertise that I seem to be lacking. I am in the setup phase of my 200 GAL tank with 300 GAL fuge/sump/return in the basement and have a quick question. <Hotay!> I want to remote my magnetic ballast for the 3x 175 W MH lights to the basement. I am thinking that if I cut the existing cable between the ballast and the lights and splice some 3 wire Romex cable in, there shouldn't be any problems, but just wanted to run it by you fine folks to make sure I am not missing something. If it matters, it will be about 30' from the ballast to the lights. <Mmm... am going to send this response to our resident "electrician", Salty/JamesG... If it were me, mine, I would NOT do this, but instead contact the actual manufacturer, ask for their input, and if they're amenable, buy new cable from them... follow their directions re re-terminating the connections...> Thanks for your time and all you do for our hobby (sickness ;-)  ) <Mmmm... Well... do perhaps wait on Salty's go here as well... I'm just too concerned re the gauge of wire over the run here, the implications of overheating, possible fire and electrical shock hazard. Bob Fenner>

Re: Lighting Question... extending wiring on/for MHs (Salty!)  7/15/06 Good day fine people!   <And to you> Once again I turn to you for a little expertise that I seem to be lacking. I am in the setup phase of my 200 GAL tank with 300 GAL fuge/sump/return in the basement and have a quick question. <Hotay!> I want to remote my magnetic ballast for the 3x 175 W MH lights to the basement. I am thinking that if I cut the existing cable between the ballast and the lights and splice some 3 wire Romex cable in, there shouldn't be any problems, but just wanted to run it by you fine folks to make sure I am not missing something. If it matters, it will be about 30' from the ballast to the lights. <Mmm... am going to send this response to our resident "electrician", Salty/JamesG... If it were me, mine, I would NOT do this, but instead contact the actual manufacturer, ask for their input, and if they're amenable, buy new cable from them... follow their directions re re-terminating the connections...> Thanks for your time and all you do for our hobby (sickness ;-)  ) <Mmmm... Well... do perhaps wait on Salty's go here as well... I'm just too concerned re the gauge of wire over the run here, the implications of overheating, possible fire and electrical shock hazard. Bob Fenner> <<Extending the wire length is not recommended, but not for overheating, as this can be overcome by using a larger gauge wire.  The problem we have here is the extremely high starting voltage of the lamps, some as much as 4000 volts (low current).  Extending the length of wire 30 feet (with standard #14 Romex) will more than likely cause a voltage drop in start-up which will lead to shortened bulb life due to longer start times, if the lamp even starts at all. This will all depend on the VA capacity of the start circuit transformer being used in the ballast.  Romex is definitely a no-no as the insulation on this wire is not rated for that kind of starting voltage, and leakage can/will occur and could lead to electrical shock.  I ditto Bob's suggestion of contacting the manufacturer re this before doing, and get information on proper wire size and type, warranty considerations, feasibility of doing such, etc.  James (Salty Dog)>> <Thanks for this Big J! BobF>

Metal halide slow warm up 7/12/06 Hey!!! <<Hey what?!?!?  Sorry... couldn't resist!>> I have a quick question regarding metal halides.  I just bought a metal halide fixture made by Current USA called the SunPod DE HQI.  This is my first metal halide fixture so I'm new to this.  My question is, is it normal for metal halides to take around 15-20 minutes for the lights to start up? <<No.  Metal halides usually take a few minutes to reach peak intensity, but they should fire within seconds.>> I don't know if the fixture I got is defective or is this just a characteristic of metal halides.  When I switch it on, the fans on the fixture do come on, but the lights don't until 15-20 or maybe even 30 minutes later. <<I would contact the manufacturer for support, or if that is not possible, the vendor that sold you the fixture.  It is possible (however unlikely) that this is a characteristic of the system you bought.  If not, it should be replaced.  Best Regards.  AdamC.>

Which 150w 10,000K MH Bulb? - 07/11/06 Hi, <<Hello>> I have a simple question (I hope) but as always I know you appreciate a little background. <<Yes, thank you>> I have an Outer Orbit light fixture with 150 watt MH HQI 10,000K and two actinic PC's.  My tank is a 58 Oceanic show set-up reef style with a DSB and fuge.  I mainly keep SPS and clams but have a few LPSs and plenty of softies.  My light fixture is about 3 to 4 inches off of the surface of the water with nothing but the glass lenses on the fixture between the water and the tank.  Everybody in my tank is and has been happy for the past year that I have had this light but now it is time (at least to my understanding) to change my bulbs. <<Mmm, yes...likely overdue on the PCs (usually changed at 6-8 months)...might could get more use out of the metal halide (highly speculative), but changing at 12 months is a popular notion>> I plan on buying the same PC's that came stock in the fixture but I am having trouble deciding what kind (brand) of MH to get.  I will still get a 150 watt and 10,000k bulb.  I hear XM's are nice but people tell me that they lose their effectiveness after about 6 months, is this true? <<Can't say definitively, but I have friends who have had negative experiences with this brand...mostly early failure of the bulb to fire>> Please help as I have been searching for an answer to this question for several weeks and nobody I have talked to as of yet have given me any suggestions. <<For my money...I would get either the Ushio or Aqualine Buschke (AB) 10,000K bulb.  The AB will appear "slightly" more blue than the Ushio, but choosing either manufacturer will provide you with a quality bulb>> Thanks much I am grateful for all the help, Adam <<Happy to assist, EricR>>

Metal Halides... mal-effect/disease?   7/8/06 Greetings from Pennsylvania, <Right back-at-cha from sunny southern Cal.> I am about 6 months into my first saltwater aquarium. I read a lot of literature on the subject before I started. I bought good filters, filter media, protein skimmer, etc.  All was going great. My mushrooms were growing, my flower pot, <Not easily kept... see WWM re Gonioporas...> and pink tree coral all seemed to be doing well as did the invertebrates and fish that I purchased. I kept reading about metal halide lighting and finally purchased a 75w retro-fit kit that I put in an additional canopy that I bought. I fitted it with fans and don't seem to have any problems with it getting too hot. I only leave it on for several hours a day. My mushrooms and corals absolutely took off and are continuing to do great, so are the invertebrates. However all of the fish except for two green Chromis died. They got what I thought was marine ick. They had these little bumps all over them, however they were not white bumps which is what I was told they would be. Do you think that it is stress or burning from the metal halide light that is causing these non-scaled fish to die? <Mmm, no... highly unlikely> Any information or opinions you might have would be greatly appreciated. I don't know what to do, but don't want a strictly liverock/coral tank. Please Help. Thanks in Advance Becky <...? Do you have a photo, photos of the infected/infested fishes to share? Cannot discern much of value from the information presented. Please read here: http://www.wetwebmedia.com/mardisindex.htm from the top to the bottom... Bob Fenner>

Metal Halides, Webmail Lateness - 07/04/2006 I just want to start out saying thank you for such a great web site.   <Thanks for this kindness.  Let me firs apologize for the delay in this reply; seems as though your email came to us in a state that few of us are able to view/respond to.  My system allows me this privilege, fortunately.> My question is somewhat simple.   <That's the kind I like!!> I want to upgrade my lighting in my tank. Currently I am running a power compact with two 65W 50/50 lights.  I have wanted to upgrade to a HQI Metal Halide but don't know how much light I really need for my tank - And if I may be getting too much. Some specs on the tank: 30gal tank with 50lbs of LR, have a 12 gallon refugium. Currently I only have Soft Corals, Mushrooms, Polyps, things in that nature.    <These do NOT need extreme lighting....> I have been looking into getting a 150 watt HQI metal halide with a 15,000K bulb, is this a good choice? <For your softies and corallimorphs?  No....  too much light, in my opinion....> Will I be able to keep Hard Corals with this lighting condition? <Not in the same system with loads of soft corals and corallimorphs.  Best to go one route or the other; too much allelopathy.  If you do choose to retain your softies, 'shrooms, etc., try at least to not have "too many", and plan on using lots of chemical filtrants to remove (or at least decrease) the amount of chemical toxins they release.> Also when I upgrade the lighting I'm afraid that some of my current corals may not adjust well. <Agreed.> Should I just reduce the number of hours the light runs for; say from 11 hours to 7 hours and gradually increase over time?   <Best to raise the light a ways from where it will ultimately be located, and slowly (over days) lower it.  The farther it is from the tank, the less light your animals will receive - this, in my opinion, is better than dropping it right on 'em and decreasing the amount of time lit.> Thanks Ron <All the best to you,  -Sabrina>

High Light Situation...Nano-Reef Aquaria   7/4/06 Hello <Hey.....there.> , I have a quick question i <I.> want to ask. <Sure.> I just purchased a new JBJ K-2 Viper 70 watt metal halide light for my 12 gallon nano.   <Lot of heat on a tank that size.> This is the only light I'll be using over the tank. <Umm...that's all you'll need.> How long should I leave it on everyday? <What is the targeted photosynthetic livestock? You be attempting to emulate the habitat, artificial or natural (assuming it is coming from an appropriate habitat) the specimen is currently in. As a general recommendation, I would say a minimum of 6 hours and a maximum of 12, 7 would be a nice median.> Also, when should the bulb be replaced? <You should be using a light meter to monitor the lumens, but again generally speaking about 12 months. Give or take a bit (or alot!!!) depending on the ballast, bulb and quality of the reflector.> Thank you!! <Adam J.>

T5 VS. Halides...The Great Debate!   6/19/06 Hey everyone, <Hi there! Scott F. here today!> I am looking to purchase a new lighting system for my aquarium and wanted to ask your opinion. The tank I have is a 72 gallon bow front with 2x55W pc bulbs (quite poor lighting for my tank, I know).  The depth is ~19' from the water surface to the top of the sandy substrate.  It is a reef tank with live rock all the way from top to bottom so I can position my corals at various heights. My tank is mostly comprised of soft and LPS corals.  In my current setup, I have: 2 well established bubble corals (Plerogyra Sp.), 1 small Galaxea Sp., 1 Open Brain (Trachyphyllia Sp.) which is currently in my hospital tank, 2 Clove Polyps (Clavularia Sp.), 1 Leather Coral (Sarcophyton Sp.), Some green and brown star polyps, and 1 coral which you guys identified as a Stylasterina Sp. In addition to these, I would be looking at keeping Anthelia Sp. (I had one but I don't think my current lighting could cut it and it slowly died off) and Octobubble corals (Euphyllia Sp.). <Interesting mix...> There are two lighting systems that I have been trying to decide between, but any other input you may have would be helpful. I am currently looking at a T5 HO system by Tek Light, which has either 4 or 6 T5 HO 54W bulbs depending which one turns out to be better for my setup. The other lighting system I am looking at is a mix between metal halides and pc bulbs.  It has 2x150W metal halides in the center with 2x96W power compacts at the sides (which I would probably have as actinic bulbs).  This system also comes with 3x1W moon bulbs, but that won't do much for the corals (It's more for aesthetics).  The model I am looking at is a Coralife AquaLight pro. <Both are excellent systems from well-regarded manufacturers. They are different in terms of flexibility, though, IMO.> In terms of price they come pretty close (comparing the MH system with the 6 bulb T5 system), with the MH system costing a bit more (but not so much as to be my deciding factor). My local store owner says that the MH system would be of no more benefit than the T5s unless I am holding SPS corals. <I would tend to agree. T5's are amazing lights, and watt-per-watt are some of the most efficient available, especially in a well-designed reflector (like the SLS/Tek or Icecap units). However, I have seen a number of SPS systems maintained with T5's, and they are amazing. I suppose if you were comparing the T5 setup to a 250-400 watt halide setup for SPS, I would say hands down, go with halides. On the other hand, it's my personal opinion that a well-designed T5 setup can equal the efficiency of 150 watt halides, with less energy consumption and heat production. Sure, halides can do some cool things, such as provide "glitter lines", but the T5's burn cooler, are less expensive to replace, and offer an ever-increasing variety of bulbs. In your situations, I'd be inclined to go with the T5 setup, myself.> He recommends me to get the T5 system he sells, but I want a second opinion as he might just be saying that so I will buy the system from him. Much thanks for the input, John D. <I'll second the recommendation, for the reasons outlined above. Do ask around on some of the hobby message boards; ask to see some pics and hear some testimonials, but I think that you won't be disappointed with the T5 setup you're looking at! Good luck! Regards, Scott F.>

Metal Halide, Shallow Tank, and Clams - 06/12/06 Hello, hope ya'll are having a fine morning. <<Mmm, yes...for a Monday>> Just got back from my bachelor party so I can't complain. <<I see>> Anyway, there is a lot of advice out there as far as the appropriate wattage/mounting depth to correlate with certain tank depths, but I can't seem to find any that fit well enough with my situation. <<Much left to personal opinion/subjective interpretation>> Currently I have a 250W double-ended HQI MH lamp with 14k bulb.  My aquarium is a 40g flat-back hex with a depth of about 20" from top to bottom.  After accounting for substrate and unused space, the greatest depth any of my charges can be possibly kept is 16". <<Okay>> My lamp is mounted approximately 8.5" away from the water surface. <<If your corals are acclimated to this lighting then this is fine.  But considering the wattage of the bulb/depth of the tank you could easily move it up several inches...in my opinion>> With the use of a fan heat is kept within sane values (78 degrees). <<Much to be said for evaporative cooling>> I'm worried though that this might be too much light. <<Depends on what you are trying to keep>> My coral charges seem fine and quite happy with the new arrangement. <<Then likely nothing to worry about>> My T. crocea (which I received shortly after) did expel some zooxanthellae right off even though it was placed in the bottom of the tank, <<More likely due to shipping/handling stress, than lighting>> currently it seems fine (mantle spread, not gaping) and I have had it a week now.  My main concern is for my smaller juvenile T. maxima (w/ darker gold coloration). <<Any Tridacnid species under 2" is problematic (seem to be especially susceptible to shipping stress/problems with acclimation)...best to obtain these clams at 3"-4" in size for the best chance at keeping them alive>> Is my concern misplaced, as these are light loving creatures, or should I consider raising the lamp considering the depth of my tank? <<What is the clam telling you?  If it seems happy and healthy then leave as is.  But I also think raising the light a bit won't "hurt" anything if you should so choose>> The T. maxima seems to be happier on the whole since I have started using a sodium nitrate solution.  It concerns me though that no matter how much I add I still seem to have 0 nitrates. <<Likely used/removed very quickly...be sure to make increases in small increments...and keep a sharp eye out for the start/increased growth of nuisance algae>> Could this solution be taken out by a skimmer or PolyBioMarine's Poly-Filter? <<Yes>> It doesn't seem likely, being a salt, but my knowledge in that area is pretty limited. I'll appreciate any knowledge you wish to pass my way.  If perhaps I have missed this information in your faq, I apologize. <<No worries mate>> Thanks for your help! James Tanis <<Cheers, Eric Russell>>

Question about DE MH bulbs.  - 5/18/2006 Hello, <Hello Andrew> I have been doing a lot of research about if it is really necessary to use a piece of UV shielded glass under DE MH bulbs.  I have heard everything from, DE bulbs put out more UV than the noon day sun, to DE bulbs sold in the US have UV shielding, the corals will color up more, etc. How much UV really is put out by DE MH bulbs?  Is the UV shielding needed more for the animals in the tank, or is it for the person owning the tank when they work on it? <MH bulbs are relatively safe as far as UV goes.  The HQI lamps do require shielding.  It is a good idea to shield the lamps from splashing water, etc. as the lamp could burst upon contact with water.> Thank you, <You're welcome.  James (Salty Dog)> Andrew Nano and Metal Halide Lighting... Nano Soup?  - 05/17/2006 Good Afternoon all, <Late night now, Hi.> First allow me to preface by saying I am relatively new to this hobby, <Welcome.> but have I have been reading all I can to get up to speed.   <Superb.> My current set-up is a stock 24 Gal. JBJ Nano Cube DX with the standard 72w of PC lighting.  I currently have stocked;   -                     One (1) Wellsophyllia 4.5" -                      One (1) Flowerpot <Not an easy species'¦.rarely live 6 months in captivity.> -                      One (1) Pod of (8) Blue Mushrooms -                      One (1) Trachy Brain 2.5" -                      One (1) Crocea Clam 2.5" <Not a great choice for a nano or power compact lighting.> -                      One (1) Multi Headed Torch Coral -                      One (1) "Green" Finger Leather Coral 5" -                      One (1) small candy cane coral -                      One (1) small pod of Zoa's -                      One (1) Coco Worm <Ditto on the comment about the flowerpot.> -                      One (1) Regal Tang 2.5"   <Not a great beginner fish, and inappropriate for this size tank.> I have read that the corals will benefit from a Metal Halide 10K-14K light source and that the color will be more intense.  If this is true, I would like to remove my stock hood and install a Current USA SunPod 150w 14K.   <In my opinion to much heat and light on such a small volume of water'¦and to be honest your animals barring the clam will do fine under your current lighting.> This unit has legs and will be perched 4" - 5" above the water's surface.  So, is the benefit worth the cost and am I going to create too much heat (current water temp 79.1 F. with heater)? <There are ways around heat but if you are new you may want to wait before you attempt to deal with such.> Thanks for all of the advise. <Adam J.>

MH height over DEEP tank  - 05/17/2006 G'day <What's Up?> I am setting up a new 30" deep tank with 150 Watt, 10000K MH, what is the minimum distance from water surface to light. <I would not suspend it much more than 12", I would shoot for around 8" as this tank is quite deep.> I will have a fan on a timer set up for cooling but am limited to how high I can have the lights off the tank, thanks. Lummo <Adam J.>

Coral and employee eyes burn from HQI sans lenses  - 05/09/06 One of my employees forgot to put the UV lenses back on some 400 watt HQI fixtures, I think it burnt my corals. Is this possible, and is there anything I can do about it? <Oh my!  Very powerful lighting with the UV lenses removed can burn your corals.  They are extremely photosensitive.  I'm not sure there is really anything you can do to fix the damage.  However I would make sure the correct levels are on them for now on, make sure your water quality is optimal and then just wait and see.  Only time will tell.  If it isn't too bad, hopefully they will repair themselves.  Good luck, Jen S.> Robert McCain Marine Fish   Marietta Georgia

Lighting/MH Bulb Problem   5/9/06 Hello, I have a 75 gal. LR tank (24" deep) with a ritteri Anenome and 4 Clarki clowns.  My suspended MH bulb is mysteriously shutting off then restarting every 5 minutes or so.  I've had the bulb for ~ 6 months.  I know you recommend 10,000K spectrum.  I'm going to buy a new bulb tomorrow, any specific brand you would recommend?  This ballast requires a screw-in type, 250 watt bulb.  I was using an Iwasaki Clean-Ace 250W, 18,000 lumen, 6500 K, and was going to look for a 250 W, 10,000 K. IYO, is this likely a bulb issue, vs. a ballast issue? (I know you're not electricians, just thought you might have experienced this with your own MH lights).  I assume if the ballast was failing the light would not come on at all, do you agree?  <I happen to be an electrician Kevin.  If you have a standard (non-electronic) ballast the problem is generally with the bulb itself.  An electronic ballast could be causing this problem as most have a current sensing device built in and will trip when excessive current is detected.  A defective current sensor could trip prematurely.>  I've always changed my MH bulbs while they were still functioning, so have never experienced this.  The light is on a timer, set for 12 hours.  Today, it kicked on, warmed up and got to it's natural spectrum (2-3 minutes), then dims and shuts off.  Then, ~ 5 minutes later, it kicks on and does the same, it's been doing this all evening.  Is this what MH's do when the bulb is failing?  <Yes, if it isn't a ballast related problem.> My poor Anenome is getting a workout, opening and closing.  It (Anenome) has always had the same 12 hour photoperiod.  I hope this brief light screw up doesn't stress him out too bad. <Kevin, I'd just replace the bulb.  If it is the ballast, then you have a spare bulb.  I'd put my money on a defective bulb as the problem.> Thank you very much, <You're welcome.  James (Salty Dog)> -Kevin  

Re: a question left out of my earlier MH email ... lamp choice   5/9/06 Sorry, one more. <Uh... of what? Where's the previous correspondence?> The choices I have found for a replacement 250 watt MH bulb are more numerous than I anticipated.  Can you please recommend one of the following for my ritteri Anenome?  Those in bold are labeled as aquarium bulbs: 1) Ushio/BLV 10,000 K (cri not listed) 2) Ushio 20,000 K (cri not listed) 3) "Standard" 10,000 K (cheapest, but I don't care) 4) MegaChrome 14,500 K (cri not listed) 5) MegaChrome 12,500 K (cri not listed) 6) Hortilux Blue 6,500 K, 90 cri 7) Eye 6,500 K, 90 cri The is in reflector, suspended 8 inches off the water.  My Ritteri is doing very well, and I would like to keep it that way. Thanks again, -Kevin <I'd go with number 1... Good bulbs, about right temp. Bob Fenner>

Lighting/Reef/MH lighting choice for 36x24x24 tank  - 5/2/2006 Hey Crew, <Hey Jimbo> Setting up my first reef tank, it is 36x24x24, and have fallen in love with MH. <Love em to death!> It will be a mixed garden but I envision a couple of easier SPS, such as Montipora and a lower light clam such as Deresa one day. If I do a frag or two of Acro it will be fine to keep it up high. Struggling with the lighting choice, I have a hood with 11" to the water, will use a couple of fans. All of the options below use a couple T5 Actinics as well as the MH. 1. Dual 175 moguls using PFO Optimal perpendicular reflector. Icecap ballast and XM 10k's. These are the retro reflectors and would be run with no glass shield. 2. Dual 150 DE's using ROIII pendants, Icecap ballast and AB 10k's. 3. A single 250w DE in the fancy new Sunlight Supply Lumenmax 3 pendant, which is supposed to give 2x2 coverage at 9" and less of the spotlight effect of other DE pendants. I don't mind the lack of coverage on the edges. <For your 24" deep tank, and the inverts you want to keep, I like option number three the best.  Do go with a HQI, much more compact.> Or if you have a better idea lay it on me! Thanks so much, <You're welcome James.  Why do I like that name?  James (Salty Dog)> James

Re: Reef Lighting    5/2/06 Salty Dog, <Scott> I have existing ballasts for MHs that I used previously.  Do HQI fixtures require different ballasts than standard MHs? <Yes.>  Would your recommendation be just to incorporate the HQIs into a hood or is there any benefit to one of the existing fixtures that you can suspend above the tank? <I'd opt for a on-tank fixture or incorporate into a hood.  The hanging fixtures will light up the room pretty well so if the tank is in a TV room you will probably see plenty of glare on the screen.  On-tank fixtures will also provide more light per watt as it is directed right into the tank.  James (Salty Dog)> Scott

Re: Reef Lighting    5/2/06 Salty Dog, <Scott> Can you please provide me with a website or distributor that I can obtain the 175W HQI bulbs at?  I am still having trouble locating anything besides 150, 250, or 400W bulbs.  Thanks. <Can't provide you with this as there are no 175 HQI's.  Sorry for my mental error.  In your 24" deep tank, I would go with three MH175's, minimum.  That should give you enough lighting for keeping clams, SPS, etc.  This suggestion is based on a on-tank fixture only.  If hanging lights are desired, I'd step up to three 250's, preferably HQI's.  Three 250 HQI's would not be too much light in a on-tank fixture also.  James (Salty Dog)>

Re:  Reef Lighting ... MH..........      5/4/06 Salty Dog, <Yo> Thanks for all your assistance.  <You're welcome.>  I have a couple final (I hope) questions.  I currently have 2 175W MHs and a 250W (I believe) MH that I used on a 150 gallon tank in 2000.  If I choose to use my existing MH fixtures (I know that the bulbs need to be replaced), and I later invest in the 250W HQIs, will the corals suffer when I switch from the MHs to the HQIs or would you recommend that I just start out with the HQIs in order to reduce coral stress?  <No suffering, I'd use the fixtures you have, just replace the lamps with something in the 10-14K range.> I hate to spend nearly $1000 on lighting which may not be absolutely necessary, but then I don't want to put a cost on a good reef set-up.  I'd rather do it "right" the first time.  If I opt to go with three 250W HQIs are there any light sensitive corals that you recommend I shy away from?  <Do research corals you have in mind before buying and know their light requirements.  There are just a few that do not appreciate intense lighting.  I've seen mushrooms blooming like trumpets in a system lit by three 400 watt halides.  Certain corals will appreciate being placed in the lower levels of the tank when using intense lighting.  Search/read our articles/FAQ's regarding this.> I don't mind using on an-tank fixture but my concern would be whether or not the fixture would be high enough above the acrylic tank to prevent any weakening or cracking of the acrylic itself.  I believe that the standard on-tank fixtures are only a few inches tall.  Can the acrylic withstand that amount of heat?  Do you feel that a canopy would be the way to go?  Would there be any additional benefits to adding any supplemental lighting?  If so, what would you recommend?  I don't see any need to add supplemental lighting if it isn't necessary.  <We've been through this in previous emails, do re-read them.> Thanks for all your recommendations.   <You're welcome.  James (Salty Dog)> Scott

Metal Halide Bulb Placement (Parallel? or Perpendicular?) - 04/30/06 Hello wet web, <<Hiya Mike!>> Let me lay out what system I have really quick to give you a better idea of what we are working with. <<Thank you>> I have a 100 gallon SeaClear System-II aquarium.  One main pump, two powerheads and a separate pump for the chiller.  2x175watt MH and a 1/4 JBJ Arctica chiller.  I have read through your FAQ's but have not gotten a definite answer. <<Ok>> My question is, is a 2-degree temperature fluctuation too much for my fish and coral? <<Not usually, no>> The chiller cools from 78.5 to 76.5 in about 20-25min and it will do this about 2-3 times per day depending on how hot the day is. <<Mmm...that's a pretty rapid drop>> Is this how this chiller is supposed to work? <<Yep>> If not, what is an acceptable range for a chiller to chill? <<?>> Do I have the settings on wrong? <<Not "wrong" per se, but could be "improved".  Does your chiller allow you to adjust the temperature differential?  You should be able to set the differential (the number of "degrees" the water temp is allowed to rise from your "set" temperature before the chiller kicks on), adjust this to 1-degree of differential to reduce the size of the temperature drop>> I have the low setting at 76.5 and the high setting at 78.5 degrees. <<Ahh!>> What am I doing wrong? <<Nothing really, all is probably fine unless you are seeing signs of stress in your tank inhabitants.  But for a more "stable" environment, you can either increase your "low" setting or decrease your "high" setting>> Also, does it matter if I mount my Halides perpendicular or parallel to the front of my tank? <<Most folks opt for "parallel", but if you have adequate light spread/coverage I don't see what difference it really makes>> Keep in mind that I have a rectangular 5' acrylic tank. <<I too have an acrylic tank...my halides are mounted parallel>> I was thinking of using the PFO parallel reflector that can also hold two power compacts or I can also use the PFO parabolic reflector which places the bulbs perpendicular to the front of the tank.  Do you guys know if these reflectors are any good? <<I use PFO reflectors, I think they are a fine product/value>> The reason I'm asking is because I heard that if you place Halides perpendicular to the front of a tank it can warp the front of it. <<Huh?! How?>> Is this true? <<Not that I've ever heard>> What can happen to my tank? <<Whether your bulbs are positioned parallel or perpendicular should make no difference in this respect>> The help is much appreciated, Mike <<Mike, considering the dimensions of your tank I think a parallel configuration would be optimal...but if you' rather go perpendicular I don't see any great problems with this either.  Regards, Eric Russell>>

Metal halide bulb brands   4/26/06 Hey.  I need to buy some new bulbs for my aquarium and am having some difficulties deciding on what type.  I have 2 175 watt bulbs over my 55 gallon right now.  I was wondering if you have ever heard of or know anything about the brand "Aragramax".  I was attracted to these because they are only $35 a piece as opposed to $70 for Ushio and Hamilton, which i have also been considering.  In your opinion, how much emphasis should be placed on the brand?  Would you go with the cheaper or more expensive bulbs?  Ushio or Hamilton?  Any other brands you could recommend?  thank you in advance <Hello Jon. John here this afternoon. My opinion is this: You could ask twenty people the same question, and get twenty different answers. You'll find that most people will actually recommend what they are currently using. With the exception of a couple of major outstanding brands (the two you mention not included), many bulbs come from similar sources. With regards to aesthetics, the colour rendering, even for bulbs with identical Kelvin ratings, can vary widely. If you can find any local reefers, or pictures on the Internet, then they may help you make your decision. As for quality, with the exception of a few German-brand bulbs, I have not found most cheaper-brand bulbs imported from Asia to be significantly inferior (indeed, I sell them myself). Best regards, John.>

Lighting/Reef/Metal Halide  - 04/25/06 Hi. <Hello Danny> I am wondering what wattage Metal Halide bulb to use over a 29 gallon. I mainly want to keep Tridacna clams. Possibly an SPS or 2. The tank is 18" tall and 30" long. I have about 20 pounds of reef sand and 35 pounds of live rock. I want to go with the 250watt 10,000k halide but my LFS says it will create too much heat. <Yes.> So, my question is, should I go with the 250 or the 175watt? And what color bulb would you recommend?  <Danny, I'd go with a 175 HQI system. Here is a link to an on-line dealer selling such a system for $169.00.  My dealer has received some PC fixtures by this company and he considers them very good quality for the buck.  I like 14-20K lighting for a reef system.  OK, here is the link.  http://www.aquatraders.com/index.asp?PageAction=VIEWPROD&ProdID=217&HS=1> I am experienced in keeping marine and reef tanks but have always had PC lighting. This is my first venture into Halides and due to the cost, I want to buy the right setup the first time. I can't really find alot of info on Halides over a 29gallon. BTW the tank is plumbed to a 10 gallon refugium. I know it's not a large tank but I am diligent in research and maintenance. Any info would be appreciated. Thanks for your time. <You're welcome.  James (Salty Dog)> Danny R. Perfecto 125gal and reef lighting Fish Stocking   4/21/06 Hello, it is Gary again.  I have a perfecto 125 gal reef ready aquarium.  I have tried, per your previous advice, to try and build my own sump system but had all sorts of issues.  I have decided to go with a LifeReef lf1-150 system.  I now am trying to decide about lighting.  I figured I would have about 4" of substrate and the tank height is 22".  This would mean that the lowest point would be about 18".  I would like to select a lighting system that would not limit me too much on what I could keep coral or anemone wise.  I was thinking three 250 watt HQI MH with 4 actinic T5s at 39 watt each.  Would this be ok or should I got down to 175 or 150s?   <I would use the small wattages> Next question is what is the difference between magnetic or electronic ballasts.  Is one better than the other? <The electronics are better> I am considering the ocean light fixtures.  Thanks again with your patience with me and all the questions. <Bob Fenner>

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