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FAQs about Metal Halide Lights and Lighting for Marine Systems 2

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

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

Stegastes fasciolatus (Ogilby 1889), the Pacific Gregory. Indo-west Pacific.

Reef On The Rise (So Are Nitrates!) and light fixture query Hello <Hi there! Scott F. with you today!> I am building a new canopy for my 55 gallon tank. It will house 2 175 w MH with Ushios and a 55w actinic power compact. My question is, should I have any glass protecting the bulbs from splash, and how high should the halides be off the water? <Well, lots of opinions on this. The height depends largely on the types of animals that you will be keeping, but as a general rule, I would mount halides anywhere between 8"-16" of the surface of the water. I'd be conservative and go for the cover glass - perhaps compensating by moving the lights lower in the canopy> Also, I am switching over from all fish to a reef, I had 65 lbs of live rock and a tomato clown in this tank, I have a sump with 10 lbs of miracle mud with bio balls in the water. I cannot seem to get nitrates under 40ppm. I do regular water changes, the tank has been set up for about 2 years. Thanks <Well, if you are using the "Miracle Mud", I hope that you're growing some sort of macro algae, which is an integral part of this filtration methodology. Do try some macro algae, if you aren't using any already. Check out your source water - Is it RO/DI, or does it have high nitrates to begin with? Also, I favor protein skimming in every system, even the "Miracle Mud" system..  Do a little reading on the WWM site under "Nutrient Export" and you'll come up with lots of good ideas to get that nitrate down. Good luck! Regards, Scott F

Metal halide cover hello, <Hi Eric, PF here tonight> I am building a new canopy for my 55 gallon tank. It will house 2 175 w MH with Ushios and a 55w actinic power compact. My question is should I have any glass protecting the bulbs from splash <I'd say yes, and as UV filters too.>, and how high should the halides be off the water? <10" - 12" is standard from what I've read/done.> Also I am switching over from all fish to a reef, I had 65 lbs of live rock and a tomatoe clown in this tank, I have a sump with 10 lbs of miracle mud with bio balls in the water. I cannot seem to get nitrates under 40 <Yipes!> I do regular water changes, the tank has been set up for about 2 years, thanks <Well, MM should be used with a nutrient export method: i.e. macroalgae. The official Ecosystem method advises Caulerpa, but I'm not fond of Caulerpa as it causes to many problems. IMO Chaetomorpha is a much better choice. You didn't mention a skimmer on your system, also you might want to look into using a DSB to help reduce your nitrates.>

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

MH lighting Hi guys how are ya? <Hangin' in there!> Question for you I have a 250 watt PFO dual ballast system, I was wondering if I can run 175 watt bulbs instead of 250? <Um, you mean on dual 175 watt ballasts, right? LOL! NOT on the 250 watt ballasts!>    Here are the specs on the tank. 72 gallon, housed are soft corals and anemones. I am also wondering if two 36 Inch actinics at 40 watts would be enough with this combination? Also what Kelvin bulb rating do you recommend for this size aquarium 5500K 6500K, 10,000K recommended for this ballast are the Iwasaki 6500K but is that enough. Thank you, Stan N. <Although you don't provide tank depth, it is likely a standard tank. You are on the line regarding wattage for about 22"-24" of water. You don't mention the type of Anemones either, which will have some bearing on light needs. I would use AB 10K bulbs for color rendition. You may not need the blue in this case, it's a matter of preference.  If your inhabitants have grown accustomed to the higher wattage light and they are thriving, I wouldn't change it.  Craig>

Throwing Some Light On Things! Bob, <Scott F. on call today> What is the difference, besides the wattage of, a double ended 150 watt HQI 10,000k metal halide bulb and a 175 watt screw socket 10,000k metal halide bulb. I know there are different types of bulb manufactures out there but I am more concerned with the difference of the two examples above for a more generic comparison. I am just about ready to make the investment into one of these two types of bulbs and fixture combinations. I am trying to get advice on the pros and cons of 150HQI vs. 175 screw type bulbs and the differences if any. <Well, there are a lot of schools of thought on the relative merits of each bulb. HQI bulbs require electronic ballasts, pendants with glass lenses (as these bulbs are not UV shielded, like mogul or medium base variety bulbs). I have read a number of studies that imply that a 150w HQI in a well-designed pendant (I use and really like the ReefOptix 3 by Sunlight Supply), can yield a higher PAR value than some 400w medium base bulbs...The implication here is that if you combine a good ballast, a fine pendant, and a quality bulb (such as the Aqualine 10000k or Ushio), you can have the PAR value of a higher wattage bulb, with greater electrical efficiency. On the down side, it seems like there are fewer bulb choices of bulbs in the HQI format, as compared to medium or mogul base bulbs-but this is changing all the time!> The tank is being made and will measure 72"Lenght X 22" wide X 20" height acrylic reef tank. I am planning the placement of two fixtures above this tank at a height of 12" for the reef tank with soft corals. Any suggestions would be helpful. My standard 125 gallon glass tank did not survive the move well from NY to AZ and so I am forced (oh well, my wife thinks my friends and I planned this so I could get a bigger tank) to have a bigger tank made, this time lighter for sure with better measurements than the standard 125gallon. Thank you in advance on this issue I have, Sal <Well, Sal...On my 150 gal reef, which measures 72x24x20 (shallow), I use three 150 watt HQI pendants (the aforementioned Reef Optix 3's), mounted 6 inches off of the water surface, with Ice Cap electronic HQI ballasts, and I have been thrilled with the results on my corals...Hey- that's what I like. You may find this a lousy setup...or you may love it! It's so subjective! Do a little research and get some opinions from other hobbyists on the WWM forum, and make your decision! It's a fun process-but a bit annoying, until you're finished! Good luck! Regards, Scott F>

3, 175 watt MH enough I just purchased a used 150 gal tank and plan on making it a reef tank...this tank is the long type and is only 24 in high...will a triple 175 MH hood be enough for most corals? Rob < This will be fine for many LPS and soft corals.  If you want SPS I would upgrade to 3 250 watters. Cody>

HQI Ballast 3/14/03 Anthony, I can get an electronic Blueline e-ballast to run a 150 watt HQI bulb for about the same price as a PFO HQI ballast.  Which in your opinion is the better buy? <I have no personal experience with the e-ballast for having been steered away by independent consumer tests/reports that demonstrated that they were "mis-representing" (overstating) their efficiency/benefits. I also live by the mantra that good things are seldom cheap and cheap things are seldom good :) Anthony>

More light for the tank?/possible mantis (03/12/03) Hi everyone! <Hi! Ananda here today...> I have been working on my second reef tank for about ten months now. I have had very good luck with my soft coral tank(4 years) so I am now going to try a SPS tank. This one is 48X24X18(90G).  I built the hood with three sockets for A future addition of a 250W Iwasaki. The light hood has two 175W 10000K metal halide lamps plus two VHO actinics. I am trying to strike a balance between color AND growth. Would the 150W Iwasaki be enough or would another 175W 10000K be more appropriate? <Whoops... you mention a 250w first, then a 150w, then a 175w... each of these bulbs requires a different ballast. Do you have the ballast yet?> The bleaching of the corallines is an issue with me, because I believe the corals will need the light. Should I add this light to the cycle now? <No need to add the light when you don't have corals that need it...unless, of course, you read by tank light.> I added the live rock back in September, and I probably won't begin stocking until May. I almost broke down and added a small school of green Chromis, but on one of my late night "safaris" I think I spotted A mantis shrimp possibly Gonodactylus platysoma (photo on blueboard.com) so I broke down the Q.T. (I will wait and watch). <I would be setting up the QT to hold the mantis! They are cool critters. Even if you disagree, there are many people who would love to care for your mantis. Do check out the WetWebMedia site and WetWebMedia chat forums for discussions on how to catch and remove these critters, as well as how to keep them or where to sell them!> The few snails and crabs seem fine. <Keep a count on them...will help determine/confirm your species diagnosis.> The water parameters are ammonia, nitrite, nitrate, and phosphate are not detectable. The salinity is 10.25, alkalinity 4.5 m/ltr., and calcium is 450. The water is changed every week at 6%. <Sounds good.> I would also like to thank Ananda and one other (maybe Anthony by the sounds of the humor maybe not) for your most recent responses. <You're welcome... not Anthony, since he always signs off on his... sounds like one of the guys on the crew didn't want to get caught/blamed by your wife in case of your untimely demise!> YES, I am the guy who spilled skimmate all over his living room carpet. The wife did not kill me (yet)! She just keeps asking me "When are you going to put fish in that d&%m thing?" <Ah, the cry of spouses of hobbyists with new tanks everywhere... I would suggest you add a couple of clownfish-shaped food clips and point to them next time she asks.> Thank very so much again Ben.   <You're welcome. --Ananda>

One MH light over reef... enough? Hi: I am in Cochin Kerala India near the Southern tip of India. <cheers my friend from afar> I have a 7ft by 2ft by 2ft marine aquarium. It is lit with one 150W MH 10000K. I have also put some 4 15 W actinic tubes and a 30W & a 20 W daylight tubes (they are on both sides of the MH. But I feel that lights at the end are not enough. What's your opinion? <Indeed... it is not enough light if you wish to grow coral along the entire length of the tank. But you can still avoid extra MH lamps by strategically keeping low light corals and decorative algae on the lower light flanks of the tank while placing the more demanding corals directly under the MH> The MH is HOT in Hot tropical India. I cannot, as of now, afford a chiller. <understood> I wanted to get some 36 W 10,000K CFLs (two to be on either end. But I do not know where to get them. I searched the web for any seller in India and the search was negative. Have you any idea where I can get them in India? <not sure where you might find them in India, but for any such aquarium hardware you seek, I suggest that you contact the manufacturer and let them earn your sale <G>. They can direct you to the closest distributor or a mail order outlet. With kind regards, Anthony>

Re: halide/glass cover Can halides be used over a tank that is covered in glass tops? If no for corals/photosynthetic orgs. , how about in a FO ? Would the rippling effect still be apparent with the glass? <Yes and yes. However, air circulation will be needed to disperse heat and provide proper air exchange.  Best to use eggcrate cover, not a solid top.  Most MH users use several fans....the danger is overheating.  Craig>

MH lighting Just a couple of quick questions after I thank and congratulate you on a wonderful site.  I am here at least 1 hr a day reading and absorbing.  Don't know what I would do w/o this website and your support now. <Thank you!!!> Ok.  In a couple of months I should be ready to start ordering supplies for my new 75 Gal system.  I had originally planned on 1 175W MH bulb w/ 2 110W VHO Actinic White bulbs and 1 110W VHO Actinic Blue bulb. However, I just read in 1 of the facts that 1 175W bulb should be used for every 2 feet of tank, so should I change my setup to 2 175W MH bulbs and 1 each of the VHO lamps since my tanks is 4 feet long? < It would be better to have the 2 metal halides, you may also want to consider dropping the white VHO and having 2 actinic VHO's with the 2 halides> How far above the water level do u recommend mounting the lights <8-16> and do you need some sort of clear barrier between the lights and water?  <yes> Oh and 1 last thing, is there a way to submit a question other than e-mail? <Nope> Thanks in advance for all your assistance and please keep up the great work.  You just don't know how much it means to beginners. < Thank you!! Keep those emails coming, Cody> Jeremy

MH vs. VHO Lighting Hello and good day to all the crew.  I also want you all to know that your service to this reefkeeper is very much appreciated.  My question is about lighting.  In terms of energy saving, which lighting setup is more energy efficient, dual metal halide 175 watt powered by a PFO ballast or 440 watt VHO system powered by a IceCap ballast.  Again thank you so much for your time and knowledge.  Travel well and happily, Timmy Nguyen <Well Timmy, this is actually more complicated than it looks, akin to comparing apples and mangoes!  MH produces more light per watt/KWH, however, your inhabitants needs, color rendition/appearance, and actual power used by the PFO/Ice Cap ballasts should be factored into your question. The PFO magnetic MH ballasts/175watt MH system will use 350 watts and produce a ??? given light output, the VHO system will produce ??? given light output but use less than 440 watts electricity. (See Ice Cap or Champion lighting web sites for comparisons and actual wattage used).  It also depends on the MH bulb used.  It is generally accepted that MH is more efficient than fluorescent lighting for a given output, but as you can see there is more to consider.  Also look into electronic ballasts for MH lighting.  Hope this helps...Craig>

Styrofoam and MH bulb orientation. Hi Crew.   Saw something in your Daily Q&A that made me think.  I just finished building my stand for 180 gallon AGA to upgrade my 90 gal. reef.  I see that some people use Styrofoam on their stand to "smooth out" any imperfections.  Could you do this for glass aquariums too?  How thick should it be?  Does the Styrofoam compress much? <I use 1" sheets. Sure, no reason you couldn't. It would compress a little more under the plastic frame, but no, it doesn't compress enough to be a concern. The whole idea is to spread the load out, instead of over any imperfection, which it does perfectly.> I have been using weather striping around the frame. <Another popular choice for glass.> Also, for the 180 I have 3 250 MH with spider reflectors.   I was going to mount the bulbs parallel to the length of the tank.  But one of the crew said they must be perpendicular to the length, as if pointing at you if you are looking from the front in.  I have my current bulbs parallel to the front on my 90 gallon and my SPS and clams are doing very well. <Hmmmm, me too!> Will I get better reflection of light into the tank by placing them perpendicular? <I don't think so. The spider reflectors are designed to reflect the most light down using the parallel facets of the reflector. Using them parallel will lengthen the area they cover and the reflector will is designed to limit the side reflection and aim it into the tank, so running them perpendicular would shorten their coverage in the length of the 180 and bleed light out the sides....not as designed.  Go parallel (with the length of the bulb and reflector parallel to the length of the tank). > Thanks for all the help and the great site!  Keep up the good work. Brad Stefanko <Thanks Brad, keep em' coming!  Craig>

Light/Reflector positioning 2/28/03 I was going to mount the bulbs parallel to the length of the tank.  But one of the crew said they must be perpendicular to the length, as if pointing at you if you are looking from the front in.   <exactly correct... horizontal and pointed at you (this maximizes distribution of light in the tank)... and further more, these bulbs have an inner glass tube that has a small nipple on it which usually must be oriented face-down as I recall for optimum burn/bulb life> I have my current bulbs parallel to the front on my 90 gallon and my SPS and clams are doing very well. <its not a matter of doing well... be simply getting better/more light and lamp life> Will I get better reflection of light into the tank by placing them perpendicular? <In my opinion/experience Yes unless you use a specific brand of reflector engineered to work otherwise> In the response I got from you on the placement of halides, you mentioned that they should run from front to back of the tank, like a T.   <correct> Since these are completely different responses, I wanted to know if this is just to different opinions, or did I misread something.   <either will work well... the reflector style (engineered parabolic or not) makes the difference> Does it have to do with the size of my tank, 90 gallon 48" long x 24" tall x 18" wide?  I just want to be sure I am doing it right. Thanks again. Paul No worries... simply heed the reflector mfg recommendation or do as I have suggested above if you use a DIY reflector. Anthony>

MH lighting and custom hood. I have a 60 1/2x18 32deep with 4" crushed coral base 200lbs primo Fiji rock some soft/hard coals urchins, mushrooms, anemone, quite a bite of vegetation.1 1" red abalone didn't know it survived warm water still kicking need to build a top for tank. Daughter keeps putting scuba Steve in tank have glass top don't stop her. so my quest on is what would you do for lighting. Have a Solar Lighting Systems 6' to long 4 tank, with 6 55wat VHO fluorescent. I have access to any type of halide from 175-1000wat. I was thinking of putting 2 250 5500k metal halide and put my 6 55wt all aqua lux in custom hood. Or ma by 4 175wat halide. how high should I place lights from water going to put a 1 piece glass piece in hood with 3 squirrel cage blowers to removes heat. Have all types of interstitial ballast that will work. what is your option on ballasts. should I spend the money and get good ballast like a ice cape or something like that. Have all the ballasts and hook ups in any size to fit a army of tanks. Just need to by special bulbs. Or will the regular halide bulbs work didn't know the cal. on bulbs. have high preacher sodium, mercury vapor liquid cooled&non liquid cooled exa. all interstitial grade. Dad is electrician & has stocked pilled. What would you do?????? I know that probably going to have to buy bulbs, no problem just need to know how height to place off water .plan to have major reef tank. All I know is have to build top to keep hands out so mite as well do it all at once even if not ready yet always leave some lights off for now didn't really want to buy more VHO cost to much. my light was $450.hopping to use what have stocked pilled would like your opinion on situation.... <OK, I see 4 questions here, 1) What ballast to use, 2)Distance of MH from surface, 3)Wattage of bulbs, 4)Temperature (K) of the bulbs. If this is incorrect, let me know. Here goes, 1)The obvious answer is to use a ballast that will properly fire the bulb you get. Not all ballasts will fire all bulbs. Check with the manufacturer. As far as brand is concerned, I have seen ballasts from $40(US) to $200(US) You will have to look at the pros and cons of each and decide 2)8-10" is recommended for Metal Halide and as close as possible for the fluorescent. 3)A 32" deep tank (28 after substrate) with SPS and anemone would benefit from 2 250W bulbs. 4) 5500K will not do. Go to at least 7100K or even 10000K. Ushio and Aqualine/Buschke (AB) are bulb manufacturers recommended by many. BTW, keeping corals and anemones that require such a wide range of lighting needs (corallimorphs to SPS/Anemones) will be very challenging. You might want to rethink your livestock list. Don>

Metal halide fixtures (02/20/03) Hey I would like to know how much would a metal halide hood cost? Can you give me some web sites with cheap hoods? Thanks <The cost varies quite a bit, depending on how many bulbs it can uses, the wattage of the bulbs, the type of ballast... Do check out the WetWebMedia sponsors' sites for some prices. Also, the WetWebFotos chat forum ( http://wetwebfotos.com/talk/) has an Equipment forum and a Local/Internet Fish Stores forum. These forums contain many, many opinions on metal halide systems and suppliers. --Ananda> Metal halide bulbs, fluorescent fixtures? (02/20/03) Hey I want to know if I have a fluorescent light bulb fixture how am I suppose to put a metal halide bulb in there is no screw hole? What can i do? <You can not use a metal halide bulb in a fluorescent fixture. Metal halide bulbs require metal halide fixtures, ballasts, sockets, etc., and the hardware is not interchangeable -- even between different sizes/types of metal halide bulbs. Start reading: http://www.wetwebmedia.com/marine/setup/lighting/fixtures.htm  --Ananda>

Cleaning metal halide hoods sorry to bother you guys for this. <No worries, fire away> 90 gal reef tank. I have a 4' hood with 2 VHO and 2 MH lights. I have a powerhead with 270 GPH flow. I have it set so it aerates. The problem is the bubble pop and i am getting a salt buildup on the hood which is starting to dim the MH. Do I need this powerhead to aerate or is their enough oxygen with the skimmer. There is a small % of micro bubbles from the skimmer. The hood is 4.5 inches above the tank. Any suggestions? Thanks <4.5" is very close for a MH and could be more like 8-10" depending on wattage. Salt creep is a fact of life in a marine aquarium. Cleaning the hood/lens should be part of your weekly maintenance. In answer to your powerhead question, a reef should have 10-20x turnover in GPH for a reef depending on inhabitants. That would be 900-1800GPH. This would include all powerheads and skimmer flow. Don>

Cleaning metal halide hoods thanks for responding. The MH bulbs are 175 watt 10000k. I was told by LFS to raise hood 4-6 inches. As far as the powerhead can it be lowered in the tank so that it is only circulating water or should it be set higher in order to spit out o2 bubbles. <If you are having trouble with low pH, the additional aeration would be beneficial, otherwise, as per above> Would the MH and to VHO 125 watts stress small percula clownfish. Lights are on 6 hrs per day. <Shouldn't. Again, I stick by the original reply, MH 8-10" above the surface.  Don.>

Reef Lighting 2/8/03 Ok, one last question. I called the local lighting supply store and asked them about metal halide lighting. They quoted me on a mini self enclosed 175W (ballast inside and UV glass shield)) from Hubbell (MIC-0175H-338). Comes with 5500K lamp for 125ea. Is this a good deal and how many would I need over a 125 gallon FOWLR tank? <Tim, after a string of e-mails, bud... I'm not sure what more to say. My recommendations are still the same: I would not use DIY lighting for fear (or without confirmation) of compatibility issues with aquarium lamps in industrial fixtures. My recommendation for aquarium lamps is 50/50 (fluor)/10K halide colors. The 5500K lamps mentioned above are too warm colored... and often contribute to significant nuisance algae growth. I realize your desire/need as all of us to save money and get a good value here... but 12 NO lamps or industrial 5500K halides will not easily (if at all) keep the cnidarians you are likely to want> I would like to retrofit them along with a few NO lamps with Actinic bulbs in them. <a bad mix in my opinion... either the NO's will be too weak and useless on a deeper tank suited for halides, or the halides will be too much on a shallow tank suited for NO fluorescents> However my Black Seal 125 Gallon has a thick strip down the middle that blocks a lot of the center pendants light if I go with three lamps. Seems like a waste. <agreed... as per the past rec', if 150 watt 10K HQIs are not an option, then 175 watt (10K Ushio, or AB) halides mounted horizontally (never pendant) with a spider reflector (parabolic). All of the latter can be purchased piecemeal at various online suppliers and perhaps some of your locals. The reflector is cheap ($15-25), the ballasts are only about $40-60 each and the sockets, harnesses, etc are mere dollars. Else its bite the bullet for a finished kit, or stall on keeping the light needy inverts> I need your input here before I pull the trigger. Thanks! Tim <best of luck, Anthony>

Amped! Hey Scott, <Hey there!> Thanks for the nice reply.  I learned a lot thru this process. <So much to learn...more and more every day for me!> One more question. <Sure!> I'm trying to calculate the amperage usage on ALL the electrical equipment and gadgets on my tank, as I don't want to overload my circuit breakers. <Done that before! Not Fun! Good idea!> My question is this: For example, my MH ballast says it's 250 watts (2.3 amps maximum input) That's just the ballast amperage?, or is that also taking into account the 250 watt MH bulb as well? <The ballast...> Am I to assume that the ballast draws 2.3 amps at 250 watts, and therefore the MH bulb also draws the same amt of current?   So the ballast and bulb = 4.6 amps of juice?  Or is the 2.3 amps written on the ballast, the TOTAL draw on both the ballast and bulb? <Yep!> Gracias, Steve <Any time! Regards, Scott F>

MH on 125 Damn, I hate doing this. I feel like a pest. Hope you don't mind, but I wanna do this right. <no worries, ask away> You aren't the first person to tell me that. Being on a budget severely limits me. <hmmm...seems that is the case for most everyone!> I was afraid of this from the time I switched over from freshwater plants and CO2 injection. How much more could running a FOWLR be I said (yeah right). Well say I can use some of the tax money (wife allowing). Would two 175 Watt Hello Light pendants be enough on a standard all glass 125? Or should I retro my hood and keep some of the old NO bulbs for added light? <Does this mean you would modify the existing hood for the MH? That would be the way I would go. Don> Need to just bite the bullet I guess. Thanks again...

Re: 250Metal halide light 20k I am about to get this light from a nice guy in my area. is 250W over 55G ok to have? currently i have 80W 10k+blue actinic light .. I want to have some opinion from you before i buy it.. i have xenia, mushrooms, polyps and 6 fish... how about electricity bill? if i say 8 hours a day?.. thanks. Bob.. <Mmm, all these questions are answered (and more) on www.WetWebMedia.com Go there and input the items above in the search feature on the bottom of the homepage. Bob Fenner>

Reef Optix III Pendants- Find Them With Google... That's what I did!  that's how I knew there was a post.  The search terms do not come up in bold, so it's possible I missed it, but since I read the page 3 times without finding it, I thought you wouldn't mind the extra help. <You could check out the manufacturer, Sunlight Supply, and visit their web site for more information. These are amazing pendants, IMO. Just got some! Good luck! Regards, Scott F>

MH lighting Hello, I have question on MH lighting that i want to buy... it's 250W 20K bulb Hamilton Metal halide. <actually... the True 10K German lamp from them would be better for most corals> I have 55 Gallon and currently running NO 80W 10k and blue actinic light over it.. <yikes! 250 watt lamps are too bright here> i have xenia, mushrooms, and polyps.. is this a good idea to buy this metal halide (of course, local guy gave me really good deal.)? <the lights are way to bright for the size of the tank and the corals being kept. Less is better here my friend. Two 150 or 175 watt lamps would be better> thank you always. <best regards, Anthony>

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

Distance of lights off water surface a bit more help, if you will.  I went through the FAQs and didn't find any recommendation as to how high above the tank (or waterline) the VHOs should be.  I did, however, find the recommendation on MH (namely 6"-9").  Thanks in advance. <agreed and correct about metal halides (MH)- 6-9" for 150-175 watt. For all fluorescents... never more than 3"off the surface (max). Light intensity is severely reduced on these lamps as you increase the distance off the water slightly. Best regards, Anthony>

Lamps off the water...and Foghat tunes in my head did you intend to qualify the MH height as limited to 150-175W? <yes, my friend> What about if they are 250W.  Would it be higher? <likely yes, but pending your species selection and the presence (or not) of a lens filtering the light. 250 watters could be towards 12"... really a wide range of possibilities, but 10-12" commonly for spread of light if not much else). Kindly, Anthony>

MH lens covers Seems to be a song I'm not familiar with. As for the lens filter, I'm not clear.  It seems many people don't use it, but the occasional horror stories lead the cautious to recommend it.  I note in many places Bob Fenner notes (with disdain, it seems) that lens covers reduce light and distort the spectral quality.  I wonder what he would personally do. <If the manufacturer supplied them (lens covers) I'd use them, but add to the weekly maintenance to remove and clean (with all turned off, cool to the touch) and replace them. The situating of 250 watt fixtures at about a foot above the water is about right. Above all, take care not to touch or splash water on these light fixtures/lamps when they're on. Bob Fenner>

Re: canopy and light design Thanks.  I'll infer from that if the fixture did not come with a cover, Mr. Fenner would not add it. <That is correct. Bob Fenner>

UV Shielding Ok, this is probably a foolish question, but what the heck, I don't know the answer and have not been able to find it in the FAQ's.  I just got a PFO MH dual bulb ballast (175 watt) and I have been reading about the UV radiation for MH bulbs.   <actually... UV comes from any type of lamp to varying degrees.> I read that the bulbs have some sort of UV protection in the form of a coating, is this correct?   Hmmm... sort of but not such that the UV is blocked completely. MH lamps have a tube within a tube> When a shield is mentioned, what exactly are we talking about. <just a piece of glass or acrylic between the lamp and the water. It doesn't take much to knock our UV> There are no specific "UV Shields" that I can find, are we just talking about an acrylic cover on the tank, or glass maybe? <exactly> Also, if someone is sitting in front of the tank looking up (through the water, canopy closed), can this do damage to a persons eyes???   <not at all> It would be a shame to have my tank all set up, then go blind! <no worries... just view it till you need glasses <G>. Anthony>

UV Shielding Do I need to use a UV shield under the MH's? I figure I do but have no idea how to shield Spiderlight reflectors. I assume from looking at thousands of pics online that many do not bother to shield the light. What's your opinion on this? <beyond protecting hot lamps of any kind from water splashing and salt creep... the UV shield is debatable. Some corals need maximum exposure to UV light for color if not health... other corals will suffer under excessive UV. My advice is to start with simple lens or shield. A plain glass canopy on the tank top will do this for you very fine. If after the dust settles and some months go by, you can experiment with removing half of a quarter of the lens and letting more UV in (through screen or grates). As you might guess... shallow water corals are better adapted to handle UV. So if you keep SPS and clams... you may not need a strong filter of UV. Best regards, Anthony>

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

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

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

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

MH Lighting for 75 gall... sans sunglasses Hello, I am in the last throws of set-up (kind of); purchasing lighting.  I have decided to go with 250 watt 10000K MH DIY, balanced with 2 40 watt actinics on a 75 gallon reef/fish tank.   <yikes... way too much light for most corals kept in such a shallow tank. 175 watt halides are much better here. Actually... the 150 watt double ended HQIs would be superb for mushrooms, zoanthids, your LPS stonies and most soft corals> I will eventually go up to a 90 or 125 because bigger is better. <definitely not the case with lighting. Corals given less light but extra food survive and grow. However, corals given extra light and less food die of photo-inhibition> I currently have a Trachyphyllia (spelling?) and a Candy Cane (Faviidae?) Coral under a mess load of NO bulbs. <rather appropriate... they are low light corals. If they end up under halide, please acclimate very slowly (use my screen method described in the archives here at wetwebmedia.com> I plan on suspending the lights higher from the tank than normal <its a waste of electricity in my opinion and a compromise for the corals you mentioned (most soft corals in fact)> because I went with the 250's so that I can expand into a larger tank and not have to worry over the lighting dilemma ever again...  Am I out of my mind? <yes. Thanks for asking <G>. 175 watt halides will easily serve a 90 gall or 125 for how shallow they are (under 28"). The 250 watts really sound like a waste to me and perhaps a stress to the corals with the hope of getting a bigger tank months/years down the road. Unless you are seriously thinking about getting rid of the low light corals and getting a dedicated SPS and clam collection, please do rethink the lava making set up planned for this 75 gallon <G>> Scott from Colorado <best regards, Anthony>

- Metal Halide Lighting - Hello Crew, <And hello to you. JasonC here...> I have a 110 Gal 24'' deep which up until now has been fish only.  I am finally going into a reef tank having purchased a Geissmann 2x250 watt 10K MH + 2 40watt actinic PCs mounted about 9" above the water surface. I have 100+ pounds of live rock, circulation is 2 300gph powerheads mounted by the surface and a Mag 700 in the sump enough?), <More circulation wouldn't hurt.> and an Oceanic 6 Protein Skimmer (any good?). <Not familiar with that brand/type.> Now that I spent 1k on the light I can afford one anemone but it's a start.  I got a Bubbletip about a week ago and placed him about midway in direct light.  He seems fine I was told to feed him 1/2" piece of Silverside once a week (Suggestions?). <Would be better to chop that up even more so that the parts were smaller.> He ate the piece and everything seemed ok.   Now however he moved way inside a cave in the liverock not even in the light.  He's opened up but it's a little frustrating because you can't see my ONE invertebrate. <That's the way with anemones... give it time.> My question is in regard to the lighting duration and exposure.  First let me say that the 250 watt double ended bulbs 10,000K are very intense they blast away the whole house.  I wonder if they are too much hence the anemone taking cover.  I keep the MHs on 9 hrs a day (noon to 9pm) and the Actinic 9 hrs (2pm to 11pm).  Is this too much? <I think so... also, the anemone needs to be acclimated to this light. I would only leave the entire lighting system on for 12 hours, with the metal halide portion on for only eight. Additional information about acclimatizing invertebrates to intense lighting: http://www.wetwebmedia.com/acclimcoralslight.htm > The room gets light from skylights (only morning light direct into tank) also.  Are the on off time right or should they be in conjunction with the natural daylight? <Hmm, hard to say... I think perhaps you should let the sun do it's thing and then extend that photoperiod with the metal halide, perhaps kicking in right when the sun's intensity via the skylight starts to fade. You probably don't need more than eight hours of this type of intense light so adjust all accordingly.> Should the light be higher off the surface. <Nine inches should suffice.> Any suggestions would be appreciated. Tanks, Rich <Cheers, J -- >

MH Lighting Well,  I don't know if you guys have ever had a sense in the pit of you stomach that you weren't doing something right... <yep... and I haven't bought inflatable sheep since then> I'm glad I followed that sense and asked you!  I have changed the components to a 150 Watt double end MH with 2 40 watt actinics.   <they will serve you very well. They are also one of the very best lights for longevity (years) and coral color rendition (great coral colors)> I do plan on having clams and SPS corals but was not planning on keeping the tank dedicated to them alone.   <and you can still have them easily in the top 1/3 of the tank> I am also glad to hear that this will be adequate for either a 90 or 125.  Not to slam my local shop, but, I wonder why they have been  plugging the 250 watt all along????????????   <its a common mistake in the industry. Sometimes by design... there is much better profit to be made by reselling industrial light fixtures rather than imported industry specific equipment> Thanks for showing me the light (ar ar ar ar).  Thanks Anthony! <my pleasure> Scott who's lost his mind! <Anthony who can't find his keys>

- Metal Halide Questions - Hi guys, <Hello, JasonC here...> I've recently come upon a 250 watt Icecap MH pendant.  My tank is 24" deep and 36" wide.  I've read that these lights only have about a 4ft square footprint so what I was wondering is, if I mount the light in the middle, could I put my LPS out to the sides? <Well... the four foot square is really more a function of the hood and reflector... but your LPS would likely be fine on the edges.> or would I need to further shield them with live rock? <This is the type of thing you will have to try and see what happens.> The animals I have right now are some brown frogspawn, a green hammer coral (branching?), a Platygyra brain, a Montipora that looked so sad in the display tank I had to give it a try (it's doing better now!, lots of growth), some yellow polyps, and some green striped mushrooms.  The light I have on it now is a 2x55w compact fluorescent hood with 50/50 bulbs.   The hammer is near the bottom, as are the mushrooms.  The polyps are on the bottom.  The frogspawn, Platygyra, and Montipora are all in the top half of the tank.  The live rock can be rearranged if need be. <Time will tell.> There's also a 1/2" thick glass strut in the center of the tank which I assume would give some shielding.  A 10k Ushio bulb is on its way as we speak.  Also, how should I mount the pendant?  12" away?  Higher due to the species I have currently? <Most likely you will want to tweak this... but higher will probably be better in your case, but probably not any higher than 12 inches.> and should it be parallel with the tank, or perpendicular to it? <Depends on the housing and reflector. Try both. While you are waiting for the bulb, check out this article: http://www.wetwebmedia.com/acclimcoralslight.htm > Always appreciating your help, Arthur <Cheers, J -- >

MH and Oceanic canopies I'm still in the design phase of a 120 gal reef and I have been looking at the Oceanic 120 for the main tank with several Rubbermaid sumps in the basement below (more on this in future questions I'm sure). Do you have any experience with mounting MH bulbs in the Oceanic wood canopies. I appears everything will fit but I'm a little worried about having the bulbs so close to the water surface. The canopies appear to be only 6" or so tall. Thanks, Kenny <metal halide bulbs closer than 6" to water surface can be challenging... do be sure you will be keeping high light creatures that will favor this. MH though are typically mounted 6-9" off of the water surface... any higher is a waste of light/efficacy. As importantly, with a commercially designed tank, be sure that you get a model with large enough drain holes for a proper reef... too many tanks just have 2-3 holes for 1" pipe or smaller. This will be inadequate for a high light MH tank full of SPS corals that need very strong water flow. Browse through our archives on this subject (overflows) and do a google search of our site as well for such topics... there is much in the archived FAQs here. Anthony>

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

Metal Halide Lighting Upgrade Hello, hope you had a great holiday. <I did, thank you!> I want to upgrade my power compact lighting to metal halide and was hoping you could help me out with a few questions before I make the investment. <Sure> What's the difference between a double ended and single ended bulb? <If you take a good look at a single ended lamp and a double ended lamp side by side, you will see that a double ended lamp is the same as the insides of a single ended lamp. It is the same technology, just different packaging. A single ended lamp is a double ended lamp with its own UV shield already built in around it.> Is one any better than the other in terms of coral health? <No> What does HQI mean? <HQI usually refers to double ended lamps and ballasts.> Should I be careful to buy a high quality ballast and what brands are good quality? <I would investigate the writings of Sanjay Joshi. He has written several articles comparing ballast strengths.> Ballasts seem to be sold to work with certain wattage bulbs. Can I use any color temperature bulb as long as the wattage is compatible with my ballast? <Yes> Is there a "best" brand MH bulb? <There are ones that are better than others. Again, Sanjay Joshi's comparisons can be quite helpful.> I was thinking of going with a 175 watt 10,000k bulb for my 46 gallon which is 36 wide x 20 tall, retrofitted about 10 inches from the surface. Current inverts include, leather, torch, Candycane, bubble, yellow polyps, and button polyps. <I am not really sure that an upgrade to MH lighting would be helpful to your current inhabitants.> Thanks for your help, Angelo <You are welcome. -Steven Pro>

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

MH lighting for a marine 125 reef Hi there crew, Charlie here. <Cheers, Charlie> In an earlier thread, Anthony was helping a guy who was having trouble deciding which wattage to go with, 250W or 400W. I myself have wanted to go with the 250W over a 72"x18"x22" 125 gallon tank. My problem is I have about a one foot wide center brace that would sit right underneath one of the metal halide bulbs in a 6 foot x 3 MH bulb configuration. My idea is to have them make me a 6 foot x 2Mh bulb hood, with the MH being on the ends, of course. If using the 250W halides, would this be ok if I used the center portion of the tank for lower light LPSs corals? <absolutely... sounds like a very fine idea! Even a 400 watt halide would both deliver well through a thick brace (quality of light, not intensity)> Would there be enuf light in the center of the tank? <depends on species kept and their needs of course. Many will work here I'm sure: Bubble coral, open brain, Blastomussa, fox coral, Cynarina, some Scolymia, most Palythoa polyps, mushrooms, etc> I should add that this tank would be mostly SPS. <and it would be best to avoid ALL of the above suggestions I have made. SPS only will give you best chances for success. Under this center brace you can keep many Montipora species and a few Acros> It seems to me that I could get some really interesting currents goin' on in here if I thought out my powerhead head placement here, by having  maybe a large cave or just sand in the middle of the tank. <I really hope that you do not use a single powerhead in this tank (any tank). Dreadful pieces of hardware. A professional reef display will have a single return pump (or two if needed... one perhaps on a closed loop on the display proper).. external direct drive pumps. Less heat, more flow, longer lasting, better made, etc. The list of disadvantages to powerheads is staggering. They are poorly made (non-grounded plugs, some non-polarized), all impart heat, few last beyond 5 years (most less than 3 years), all leak in time (electrocution hazard), flow is laminar and not easily harnessed, multiple pumps require multiple servicing events, said pumps are ugly in the display, and the list goes on. Do consider hooking your return pump up to a teed manifold just at the water surface instead. Clean, professional, easy to service and better flow for the reef> Tell me what you guys think, I'm really looking for an interesting look in this tank. Thanx, hope you can help. Ce <have you seen my suggestions in the coral prop book for building arches and caves, suspending reef structures... and the rant on powerheads at length? Might be of interest to you. Best regards, Anthony Calfo>

Metal halide lighting Hello, <Happy Thanksgiving> My questions have to do with my 65 gallon marine tank which I want to develop into a reef system. Size of tank is 36 long, 18 wide, and 24 deep. Would a 400 watt metal halide be overkill? <it would be overkill and quite frankly dangerous for almost any common invertebrate found at your LFS> Would a 250 watt metal halide be suitable? <still possibly too much unless you are keeping only clams and SPS corals. One cannot pick their lights before deciding which coral will be kept. If you like soft corals, mushroom anemones or LPS (like open brain, elegant, octopus, hammer, bubble corals) then 250 watt is still too much.> Would a 250 watt HQI double ended be a better choice compared to 250 mogul base? <yes... a better lamp by measure> With a 250 watt metal halide would I still need to supplement with fluorescent actinic? <its not the wattage that precludes your need for actinic but the fact that all popular halides available including 6500K Iwasakis have enough actinic for corals. Keep actinics just for aesthetics if you like> And, would one light be sufficient for the size of this tank? <with a good enough parabolic (Spider) reflector... yes. A 250 watt for SPS and clams... a 175 watt for all else> Thanks much, Tim <best regards, Anthony>

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

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

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

Changing from PC's to MH's II Steven, Thank you for the response to my questions. By the way the Saddle Grouper I have scientific name is Plectropomus laevis. <Oh yeah! He is going to be a big boy!> One question, I neglected to ask was how far above the tank should I place the metal halides? <So that the actual lamp is 12" off of the surface of the water.> My clam lives on the bottom of the tank (on 3" of sand), but the corals are about middle of the tank. I do not have live rock going high up in my tank; all the live rock builds up to about 1/2 the depth of the tank where the corals and any new clams would go, so I assume this has an affect on where the lighting is placed.  Thanks again, Kevin <You are welcome. -Steven Pro>

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

Metal halide I'm going to bite the bullet and upgrade to MH lights for my 110 tank. My question is this, some things I have read say I need dual 400 watt because my tank is 30 in deep...some say I only need dual 250. What says Bob? <It all depends on what photosynthetic animals you want to keep, and what you want to do with them... that you have matching circumstances to handle boosted metabolism... 400 Watt fixtures are HOT! . Please see the vast amount of information regarding lighting issues on www.WetWebMedia.com.> Thanks, Robert <You are welcome. -Steven Pro>

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

MH Lighting I'm planning to purchase & install 175w MHs over my 125g (tall) tank.  Is there any appreciable difference/benefits between vertical pendants and horizontal canopy-style setups?  Is it purely aesthetic or does one put out more light, less refraction, etc.?  I know that WWM typically recommends Iwasaki & Ushio bulbs...could I use these in a pendant or do you have to get a different bulb designed for a vertical orientation?  Thanks so much for your counsel on this!  I've been pouring over your FAQs, etc and studying as much as I can get my hands on...just haven't found the answer to this yet. John <<Hi John, This is Craig answering while the WWM Gang is at play at the MACNA event. Yes, there is a substantial difference in the amount of light and how it is reflected in to the tank and how much it will illuminate. The vertical pendants won't cover as much area and are better suited for spot lighting or penetrating deeper water in one spot. The horizontal types use the length and output of the bulb to your best advantage and good ones reflect most if not all of the light downward into the tank. This will give you more coverage and intensity from the same light. This is important for you due to the depth of your tank and relatively low wattage of your lights.  Good reflectors make a big difference. The brand and color of the bulb is a personal preference.  Make sure you buy the right bulb/ballast combination.  Retailers usually do well in this regard. Most MH bulbs for aquarium use a universal, they can be vertical or horizontal. Hope this sheds some light on the subject!  Craig>>

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

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

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

Yet Another PC vs. MH Query Hi Bob, I've read through the FAQ on lighting but can not decide which option is best for me. <begin here for starters, my friend: http://www.wetwebmedia.com/marlgtganthony.htm> I have a 72-bowfront (48Lx13-18Wx23D) where I want to keep various corals and one or more anemones (I read these really like the light).  <please do not mix motile anemones with sessile corals... it is a recipe for disaster in the long run (1-3 year picture). Inevitably one will die. Anemones truly need dedicated species tanks to be treated fairly> I'm considering a 4x55W PC setup or a 2x175W MH with possibly a fluorescent or PC actinic.  < the MH are a better route for most... more bang for the buck so to speak. The PCs simply do not penetrate deep enough into the aquarium and you will be limited to cnidarians in the top half on the tank only... may be limited by species too> This gives me anywhere from 3-5+ W/gal which is what I've always heard, but which is it?  <such rules of thumb are inaccurate and useless.. explained in article above. Pick your species first then pick your lights bud> I understand you can't compare watts-to-watts between systems, but how much light is necessary?  <as much as your selected species need... hence the need to make a guest list first. Are you keeping low light cabbage corals or high light yellow Porites? Etc> Will coral grow near the bottom of the tank with 3 W/gal of PC?  <very few species unless you plan to feed heavily to compensate> With MH, will I have to worry about what I place near the top?  <again... depends on the needs of the species you pick. Corals in the trade are collected anywhere from 0 to 80 feet at depth> Thanks for any advice you may have. Jason Jacobs <best regards, Anthony>

Lighting Hello, I was wanting to know if there is a 100 watt metal halide? <I remember seeing a few around when MH's first came out.> Right now I have a 175 watt on my 20 gallon <Wow!> and its a little bit to much for the algae growth. <Algae growth is related to nutrient levels, not exactly lighting. While algae needs light, nuisance algae are dependent more on excess nutrient levels.> I'm at about 8 watts per gallon now. That's why I was wanting to know about the 100 watt to bring it down to five watts a gallon. <It would be easier to convert to PC lighting. Even if you could find a 100 watt fixture now, getting replacement lamps could become a real problem.> Would I have to buy a whole new ballast to change the lighting? <Yes> I really wanted to keep it inexpensive because I only have about 120 dollars in the 175 watt with the ballast. Its a Hamilton Technology ballast. I got it so cheap because my friends store was going bankrupt so I couldn't pass up the deal. <Perhaps the cheapest route for you is to just buy a larger tank.> Do you know anything about the D.A.S. protein skimmers? <Very little, I have used their in tank air driven skimmers and have not been happy with them, but no experience with any of their stand alone models.> He also sold me this for 50 bucks. <Good price> He said it was for about a 250 gallon tank but its removing a lot of stuff from my 125 gallon now. <As long as it is dark and consistent (one cup per day is optimum) I would be happy with it. -Steven Pro>

Metal Halide Lighting Hello First of all let me say "God bless America." <Indeed> My question is, can I place one metal halide fixture on one side of the 75 gallon tank and use power compacts on the other side. <Sure> The reason for my question is to be able to keep the light loving corals on one side of the tank and the mushrooms and so on, on the other side of the tank where the light is not so intense. I am also asking this to see if there is a reason I have never seen this done. <I have seen it done once before on a 180. The left side four feet have two 175 watt MH's, while the last two section is lit by PC's. It is noticeably darker on that side, but functional.> Thanks in advance, John S. <You are welcome. -Steven Pro>

Metal halide exploding Hi Bob, <Anthony Calfo in your service> I was just wondering if you had heard of metal halide bulbs exploding very often?  <not often... but not uncommon. I've had it happen twice in ten years and heard a dozen or so aquarists have the same. Commonly occurs when placing a reef lamp in a cheap industrial fixture like those awful 400 watt units :p Seriously.> I know splashing water on them might cause it,  <of course> but I had one explode inside a pendant with a cover once.  <Hmmm... care to share the brand name? I have my suspicions just the same. Will be very surprised if it is an AB or Iwasaki although defects sure do occur. All assuming that this isn't an industrial (non-aquarium) fixture (some lack necessary components to run some reef bulbs)> Steve Tyree told me he had heard of it happening several times. Have you? <yep> Mitch Gibbs <kind regards, Anthony>

Re: Metal halide exploding Thanks Anthony, <cheers, mate!> At least I know I'm not completely losing my marbles.  <that makes one of us :p> It was a few years ago when mine exploded (imploded whatever). I had it in a Hamilton fixture and I don't recall the brand of the bulb anymore. It was 175watt either 6500 or 10,000K.  <interesting...yes. Perhaps just that 1 in a 1000 inevitable defects> It wasn't one of the Sunburst however. <heehee... I didn't mean to imply anything about a certain brand that seems to deliver exactly what one pays for :P> Thanks again see ya at MACNA, Mitch Gibbs <excellent, my friend! Be seeing you soon. Anthony>

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

Metal halide lights Hello. <cheers> I know this may sound like a stupid question but I wanted to know if, There are any metal halide systems you can use to rest on top of your aquariums hood.  <not a stupid question... but you cannot rest the MH fixtures very close to the water surface. For safely... MH need to be 9"+ off the water. Still... many people have custom canopies made with long "legs" to get the 9". If you are not handy to make a proper canopy... just consult a local cabinet maker and show him pictures of such canopies from FAMA magazine, etc> Just like a normal fluorescent strip light. I am asking this because my 125 SW fish tank is in my basement and the ceiling is not strong enough to support lights hanging from it that are that heavy. Thank you for the info!!!! <the lights aren't that heavy bud?! Unless you are talking about those piece of crap 400watt construction MH fixtures with the ballast on the bell. Very inappropriate for aquaria. An aquarium MH bell has a remote ballast that can sit on the floor. Such bells are only as heavy as a bulb, ceramic socket and aluminum housing... like a feather! Do reconsider my friend. One 175 watt MH 10K bulb per 2 feet of tank length will serve you well. Anthony>

Affordable Metal Halide lamps and some questions Dear Mr. Steven Pro, Top of the morning to you! How is it? <Not too bad.> I would like to know if Kent's Phytoplex will work for my newly purchased Leather Toadstool. <Probably not necessary.> I perused WWM's site but could not find anything definitive on the above. Also got my PC retrofits yesterday. The animals are reacting very well towards it. However, the built-in fan for the sounds like a WWII plane hovering above my apartment! <Sorry to hear that.> Is it ok to remove the fan? <Perhaps, watch your tank temperature. You do not want it to go above 82*F or swing more than 2-3*F daily.> It's a Jalli 2X55W 24" retrofit kit / independent switches running a 7100K and a 10000K actinic blue bulb. Nevertheless, Kudos to all the folks @ WWM. You are doing a bloody great job. Please let me know how I may return the favour. Laters, Mimi Eliza Rogers <Have a nice day! -Steven Pro>

Affordable Metal Halide lamps and some questions Dear Steven Pro, How do you do? <Very well, work went fine today.> I went ahead, took your advice and purchased a Jalli 24" 2x55 watt PC (comes with built-in fan and independent switches for both bulbs) from an e-tailer for $187. The bulbs were 1 55 watt German-style 10,000K actinic / 1 55W 7100K. I will be getting it early next week. My concern is acclimating the corals (bubble, green open brain and brown polyps) to the new intensity. I currently have an 18" 15W 10000K actinic bulb. So this will be a huge move of 15W - 110W. <Yes, a big change, but a big improvement, too.> The green open brain sits high on the LR about 2-3 inches from the surface. The bubble and brown polyp sits on the 2" sand bed. Depth of tank is 12". I was thinking of running the 7100K bulb for the first 2 weeks before turning on the actinics. <A good idea> Photoperiod at present is 15 hours. I will reduce it to 8 hours with the PC's. <Just in the beginning or for the duration. A normal twelve hour photoperiod would be my recommendation after a proper acclimation time period.> Also concerned about my coralline algae being bleached from the increased intensity . Water params are as follows: ------------------------------------------ Sg 1.025 pH 8.2 Nitrates 0 Nitrites 0 Ammonia 0 Ca 380 ppm Alkalinity 10-12 dKH Temp: 77-80 I am using SeaChem's Reef Calcium twice a week. Please advice and thanks in advance. Best, MER <Please see Anthony's excellent article on acclimating corals to new lighting, http://www.wetwebmedia.com/acclimcoralslight.htm -Steven Pro>

Re: Lighting Thank you for your prompt response to my question. Your comments raised a couple of other matters. Manufacturers of MH lights recommend one bulb for every 2 feet of tank length and 175 watt bulbs for tanks up to 20 inches deep I believe. <I would use one metal halide lamp for every 4 square feet of tank surface area, one lamp per 2 foot by 2 foot area. Also, the brand of lamps plays a key part in how much actual light is emitted. One of the best tanks I ever saw had Aqualine-Buschke lamps and that tank was 28 inches deep with nicely colored Blastomussa, Fungia, Heliofungia, and others on the sand.> The aquascaping plan I have in mind for my 6 foot long tank has 2 coral bommies separated by about 6-9 inches of sand near the center of the tank. I don't plan on having the rock touch the glass so there will also be a bit of sand between the tank sides and the live rock/coral. Would one metal halide bulb over each bommie with a couple of PC bulbs suffice? <Depends on what you wish to grow, in particular, but yes for most things.> Since my tank is 24 inches deep do I need to go with 250 watt bulbs (Iwasaki 6500s seem popular) <If you intend to keep predominantly crazy colored SPS, use the 250 watt Iwasaki's. Otherwise a mix of LPS, SPS, and soft corals would be better served with the 175 watt fixtures, with good quality lamps. This is really the big issue with most people and their "need" to use higher and higher wattages.> or will the 175s be Aqualines you suggested be ok? Also, how often do the MH bulbs we are talking about need to be replaced?

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