Please visit our Sponsors

FAQs about Light and Lighting for Marine Systems 7

Related Articles: Marine Light, & Lighting, Marine Aquarium Light Fixtures and Canopies, Lighting Marine InvertebratesAnemone LightingCoral System LightingMoving Light Systems

Related FAQs: Marine System LightingFAQs 2, FAQs 3, FAQs 4, FAQs 5, FAQs 6, FAQs 8, FAQs 9, FAQs 10, FAQs 11, FAQs 12, FAQs 13, FAQs 14, FAQs 15, FAQs 16, FAQs 17, FAQs 18, & FAQs on Marine Lighting: Fixture Selection 1,  Fixture Selection 2, Fixture Selection 3,  (incandescent, fluorescent, MH/HQI, LED, natural...), Lamp/Bulb Selection 1, Lamp/Bulb Selection 2, (See Fluorescent, LED, MH... below), Installing, Waste Heat Production/Elimination, UV Shielding, Measure, Troubles/Repairs, By Manufacturer Make/Model: & Actinic Lighting, Metal Halide Lighting, Fluorescent Lighting, Compact Fluorescent Lighting Small System Lighting, Lighting Marine Invertebrates LR LightingTridacnid Lighting

Is Lux the same as lumens (for light parameters)? <Nope. Please see here: http://whatis.techtarget.com/definition/0,,sid9_gci542011,00.html Bob Fenner> Thank you, Luke

Lighting & Sump Ok, guys, (Anthony & Steven) <Hi Cathy! How's it going?> We "fixed" the lighting. One of the DFWMAS folks sold us some lights (Thanking him very much, saved us a bundle). Here is what we have: 2 VHO blue lights - which causes a very weird effect of making the daisies, mushrooms, and polyps "glow" green for the "dawn" - and two MH, Hamilton 175 watt 10,000K each. <Sounds perfect!> The VHO also stay on a little longer at night for "dusk". My kids find the glowing part to be pretty cool :-). <Me too!> The tank looks more green than blue (when the MH are on), though, and I'm not sure I appreciate the difference in lighting. <Perhaps you would find different MH lamps more pleasing. There are a ton of lamps marketed as 10,000K, but there are differences between them. I prefer Aqualine-Buschke myself.> The same guy who sold me the lights also gave my some frags - a "Devil's Hand", some frogspawn, and two green mushrooms. I've since lost one of the mushrooms, it moved and I can't find it! Wah! <I bet it is still alive somewhere. There are very tough and adaptable.> The Hand went in the upper third of the tank, and the frogspawn is smack in the middle. But if I do a water change, the Hand will be out of the water, so should I move it, or will it be ok? <You can wave the polyps down while performing the water change and it will be ok. Or you could move it down some, but only once.> Also, I noticed that on the dailies today, Anthony recommended that a sump should be one third to one half the size of the main tank. <I think that was me.> Ummm, y'all told us 20 - 30 gallon, but we have a 140 tall? And we only purchased a 20 gallon. Should we find a bigger tank? <It is workable as is. I would have preferred the 30, though.> We were wondering, as the 20 seemed too small for sump, refugium, and mangroves to all be in there at once. <Agreed> Maybe I can find a 3' long tank that someone wants to unload. <If cheap enough, I would consider making the change.> Boy, wish I had found this site BEFORE I started all of this! Would have saved me time / trouble, and spared an awful lot of fishies! Please let me know your opinions on the lighting, my Devil's Hand, and the sump - thank you kindly! -Cathy in Texas <Talk to you later! -Steven Pro>

Lux Meter Hi, I have a question about Lux meters. If I purchased one, I could get Lux information for different levels in my tank. How could I put this information to good use? Is there something that tells me, you need "x" amount of Lux for coral "a", and "x" amount of Lux for coral "b"? Most information I read says, certain corals prefer low, medium, or high amounts of light. Are these meters very useful? <Ahh, not much use for the average person. There aren't really any books or references with Lux recommendations. It's easier to understand what is meant by low, medium, and high and their relation to water depth, penetration and intensity. It's also best to find the best general optimal conditions for the inhabitant in question and acclimate up to that level slowly.>  Cheers, Craig Thanks, Angelo

LIGHTING QUESTIONS Dear Bob, <Steven Pro in this evening.> If you don't mind I would like to pick your brain on a lighting project I am undertaking. I have a standard 90 gallon aquarium. I am planning to install power compacts totaling 530 watts. I will have 4 96 Watt quad bulbs(50%white/50%Blue) with 2 65 watt actinic bulbs. The bulbs will be in front of an Aqua Mirror which I am sure you are aware of is a highly polished piece of aluminum. Will this be enough light to raise a wide variety of hard and soft corals? <This should be just fine for most soft corals, LPS, and some SPS.> If this is not enough or overkill what would you recommend? <It all depends on what you wish to have grow.> If it is not too much trouble I have a second question for my father. He has a 180 gallon acrylic bowfront tank and is extremely unhappy with the results he has gotten with the use of 4 96 watt power compact lights. Giving your honest and professional opinion what type of lighting would you recommend, metal halide or power compact? <Metal halide would be the most cost effective solution.> Depending on which light source how many watts per gallon? <A useless and arbitrary rule. All discussions of lighting must first start with what you want to light. If your father wants a LPS dominated tank, I would recommend one method versus a clam and SPS dominated tank.> I am suggesting 3 250 watt 10,00K bulbs by Aqualine with the use of PFO ballasts by Champion Lighting, as well as the use of several actinic blue power compacts. Does this sound correct to you? <Very good for a SPS and clam tank. Please see our coverage of lighting issues/questions in the FAQ files of www.WetWebMedia.com for additional enLIGHTenment (I crack myself up).> Thanking you in advance, David Jablonski <You are welcome. -Steven Pro>

Lighting for FOWLR Anthony, On lighting for a FOWLR can PC and VHO lighting be used together? <certainly... very attractive color/rendition. If the tank is less than 24" deep it may be more light than you need though. No harm for most fishes though. Aesthetically attractive for sure> Thanks, Mark <kindly, Anthony>

Quick question and Thanks (marine lighting) Thanks for the past advice; you said I would be back! I'm still in the process of updating (rebuilding/recovering) a tank given to me, ~100 gallons 60"l x 24"h x 20"w, finally got all the water quality issues under control, water flow > needed, etc. PHEW that's behind me. The setup has tons of Live Rock, Snails (4x types), 3+ emerald crabs, hermits (blue & red), 2 banded cleaner shrimp, 2 wrasses (watermelon), tomato clown, anemone, Feather Duster, Damsel (yet to be id.ed) and a tang (again yet to be id.ed). <Do peruse the coverage on www.WetWebMedia.com for an accurate ID.> (Did I mention this was a "given to me project"..) Now I'm down to lighting. Currently I have/had: 1-bank 2-40W VitaLites 1-bank 1-40W Coralife 50% natural 6000k/50% actinic 03 blue & 1-40W corallite 20,000 Kelvin high intensity daylight This "as is" is "not enough" for the tank I would suppose. <Not enough for that anemone.> While I really "don't plan" (you know how that goes), don't plan on getting in to the "exotic" corals (read demanding, difficult, etc) I would like to get a "few". <You already have one, the anemone (demanding, difficult, etc.).> Now the problem, the ballast on the VitaLites went. So it's replace with the same or upgrade. <Upgrade> Again, I move toward the upgrade that is reusable as I plan on ordering a custom tank replacement for this location and migrating as much as possible. <Ok> In the comparisons of standard, ultra compact, etc. do I really need a MH if I don't really plan on getting into the corals? <It depends on what you want to keep.> The replacement tank will be deeper, but probably only about 30" vs. the 24" now. I was thinking about using a Sea Quest Marine PCMH60 retrofit. It has 2-65W Ultra-Actinic bulbs & 2 175W 5500K Metal Halides. <Ok> I have physically seen the Sea Quest products in-use in several LFS's around the area, they say they have had no problems, etc. Is this "overkill" for the tank? <Not for many photosynthetic animals.> Is Sea Quest really an OK product? <I have no personal experience.> The alternatives I've found have not been as well constructed in regards to the MH area. Again, thanks for your advice. ~Robert Molenda P.S. The pics are on the camera, just got to get my arm out of the tank and on the PC, then it'll be on the web. <Have a nice day! -Steven Pro> Reef Lighting Anthony, I'm trying to decide on lighting for are second tank. Since its not going to be a full reef tank, I don't want to use MH.  <Hmmm... MH versus fluorescents is all about species selection... remember :) Sans halides usually means sans clams and sps unless the aquarium is very shallow> I keep going back and forth on PC or VHO. Stocking with corals all be limited to what ever the Imperator won't eat, which is basically: assorted leathers, colts, and mushrooms.  <agreed with fluorescents on this count for sure. Do consider Gorgonians too.. they are very noxious and rarely eaten by fishes. Very fine "corals" for non-reef safe fishes> The tank is 72 X 18 X 20, it has canopy so I can use retrofits. The problem is that the canopy is hinged in the middle and the part that lifts up is split into two sections.  <Ughhh> I could use 2 72" VHO for the rear section but for the front section there isn't enough room for 36" bulbs. I don't feel that the 72" VHO would be enough lighting. The other option would 4 X 96, but since the cover is hinged in the center, I wouldn't be able to center the light over the tank. <sounds like a good case for 4 pc lights rather than 2-4 VHOs. Emphasize daylight colors under 10K> Thanks, Mark <best regards, Anthony>

Lighting  Buenos dias! My eyes are about to fall out from reading all I could find on this subject, but I still have a few questions. I have a 72lx18dx24h tank which I am setting up as a reef tank. I would like to keep soft corals, some hard corals and fish. I am just about finished with the plumbing and am now trying to decide on a good lighting choice. I am still undecided between MHs and compact fluorescents (or is it power compacts?). <Either or power compact or compact fluorescent.> I initially thought either 3x 175 watt or 2x 250 Iwasaki 6500 MHs with some actinic lighting would do the trick, but it seems like PCs would be the more cost effective alternative (no need for a chiller!) in the long run. <The necessity of a chiller with metal halide lights is a complete hoax. They are no hotter than PC's and most heat problems are because of improperly designed hoods, stands, and lack of AC in house.> If PC can be used I am not sure on how many bulbs (or watts) I would need. Any suggestions? <A whole bunch! No really, for this tank and to match the intensity of the 3x175 watt MH option, you would at least need 8x96 watt PC's. Not really a cost effective option when you consider replacing lamps every year. I would use the 3x175 watt Aqualine-Buschke MH's.> My second question is about acclimating corals and inverts to LESS intense lighting. Someone locally is selling corals from their tank. These corals are doing great under 2x400 watt MHs. I am interested in buying some corals from him but was concerned how well they would adapt to the less intense lighting in my tank. <Some may never adapt. There are very high light corals, like blue Acropora or Yellow Porites. These may all change color, some may not be able to make the transition. Not much you can do to acclimate them other than keep them relatively high in your tank and hope for the best.> As always, you guys are the best! Hasta luego! Gerardo Gomez <Have a nice day! -Steven Pro>

PC vs. MH Hi, Thanks for the quick reply!! I like your idea about MH on one side and PC on the other, but I was wondering if this causes one side to appear brighter than the other? <likely some difference yes... but necessary and interesting in my opinion to keep a wider diversity of symbiotic corals. Do experiment if you like> Thanks, Christie <kindly, Anthony>

Lighting I am setting up a 70 gallon salt water aquarium. The glass lid broke while in storage and the hood only holds two lamps that meet in the center. For the lighting to be correct (live rock, coral, etc.) I am assuming I need a hood that would hold 2 or 3, 48 inch bulbs. My tank is older and does not have a support bar in the middle. Can you recommend a solution for a new hood and lid? Also, what type of bulbs do I need to produce the proper lighting? Thanks, Kristy < Yes, you have a couple of major options: to build or buy an adequate housing/hood to accommodate sufficient fixturing and release heat (if necessary). If you want the fastest, though not cheapest route, take your old, broken glass (or good INSIDE edge measurements) to a glass shop (you can find them in your "Yellow Pages") or even a large "department store" retailer like Home Depot/Lowe's (they have glass for sale and will cut, bevel it for you), and maybe even check your retailer (with the dimensions (outside this time) and pertinent notes so they can figure out the Brand name of the manufacturer... and have a new glass made or replaced. The real livestock store will have new, cuttable back-edge material that will attach to the glass so you can cut out where your inputs/outputs enter/leave the tank top. You can make a "hinge" with a bead of silicone rubber (the store will show you how) by running and pinching a bead of aquarium-use silicone between the front and back glass top panels. Fixtures and lamps and a hood can be bought as units. I personally prefer compact fluorescents for this size, shape aquarium for looks and function... Alternatively you can have made or make a canopy type arrangement with or without a glass barrier. This needs to be tall (quite tall if you're going to use Metal Halides), and have provisions for ventilation. Possibly one or more "muffin" fans wired with your timers to come on when the lights do... Manufacturers of pre-made hoods/lighting can be found best in FAMA magazine (Freshwater and Marine Aquarium), and contacted via the Net... once again, investigate your possibilities before deciding. Much more on these issues can be found under the subjects, light, lighting at the wetwebmedia.com site. Bob Fenner>

Lighting Question Hi, before I ask this question, I would just like to say that the subject of lighting is still the most confusing and hardest to understand.  <agreed...> As much as I read I still don't have a good grasp on what is ideal for a successful reef aquarium. <see my article on lighting without controversy here: http://www.wetwebmedia.com/marlgtganthony.htm > So with that said... I was looking into buying a JBJ 36" Formosa 192 watt total power compact fixture for my 46 gallon bow front tank (which is 36" wide).  <a nice outfit but remember that watts per gallon means absolutely nothing... its all about the needs of the corals (have a specific list of species you are targeting and their needs) and then determine how to deliver that light at depth (fluorescents are nice but not very effective beyond 12" of water> Do you think this would be adequate lighting for most corals or clams in a fairly small 46g tank, 2 96watt pc bulbs, daylight and actinic? <enough light for most if they are kept in the top 12" of water. The clams and SPS corals might struggle a bit if you don't have a refugium or otherwise feed them well. You may be much better served by a simple and single 175 watt 10K Aqualine Metal Halide> Thanks, Angelo <best regards, Anthony>

Re: Lighting Question Thanks for the info, it certainly makes sense to go with MH. <indeed most efficient for tanks deeper than 18-20"> One more question, how do you suggest I mount it above my aquarium?  <definitely canopy style with a nice parabolic reflector (like the new spider reflectors...excellent and reasonably priced> Since my tank is on 36" wide, should I go with a pendant? What do you think? <pendant orientation wastes/focuses light to greatly... you wanted a wider dispersion. Mount lamp horizontally and perpendicular to the front long side... best distribution of light this way. Lamp is to be 9-18" off the surface. Best regards, Anthony>

REPLACEMENT LAMPS I currently own a 100 gallon aquarium with a few soft corals. The lamps are now 1 year old. <Old for any fluorescent lamp. My rule of thumb is replace NO lamps every 9-12 months, VHO's every 6-9 months, PC every year, and MH's every 12-18 months.> Currently, I'm running 1 50/50, 1 actinic, and 1 AquaSun. To cut down on hair algae and to provide better lighting, I am going to replace the AquaSun and the 50/50 with 2 Aquasuns 10,000 K. Currently, the AquaSun is only 6500 K. Is this a good idea? <It may help somewhat with your hair algae problem, but nutrient control is more important. Whatever your lighting is, if you have too many nutrients, hair algae is going to thrive.> Thanks, Dave d. <Good luck! -Steven Pro>

Re: lighting (deal for invertebrates?) Bob ok...let me know if I messed up....I think I made a good buy tonight...but I'm not sure now that it's installed. I purchased a 48" CustomSeaLife Power compact "smart-lite. It has 2, 65 watt smart lamps which are one tube actinic and the other true daylight. This is on a 110 gal tank I was planning on putting 4, 50/50 Coralife bulbs. Robert <read here to see how your targeted invertebrates will be best served: http://www.wetwebmedia.com/marlgtganthony.htm Best regards, Anthony>

Inexpensive lighting being a poor reef keeper who can not afford metal halide at this point, would I be better off with 2 -50/50 and 2- 20,000K Coralife bulbs or 4-20,000 or 4 50/50? <<Depending on what you want to keep, the more the better.>> I do want to keep several different types of corals and know that many need very high-intensity lighting. <<Well... best to plan it all around your budget and avoid purchasing livestock that really require the metal halide [clams & most SPS corals].>> thanks Robert <<Cheers, J -- >>

Inexpensive lighting being a poor reef keeper who can not afford metal halide at this point, would I be better off with 2 -50/50 and 2- 20,000K Coralife bulbs or 4-20,000 or 4 50/50? I do want to keep several different types of corals and know that many need very high-intensity lighting. <with any such fluorescents... be sure that all corals are kept within the top 10-12" of the water surface and most importantly (!) that the lamps are mounted no further than 3" off the surface of the water. With that said... for optimal coral health, use heavy daylight colored lamps emphasizing 6500-10K colors. 20K lighting is too blue for coral health. 4- 50/50 bulbs might be best. Remember to replace bulbs every 6-10 months for best success. See a lighting synopsis here: http://www.wetwebmedia.com/marlgtganthony.htm > thanks Robert <best regards, Anthony>

Lighting Being a poor reef keeper who can not afford metal halide at this point, would I be better off with 2 -50/50 and 2- 20,000K (Coralife bulbs) or 4-20,000 or 4 50/50? I do want to keep several different types of corals and know that many need very high-intensity lighting. Thanks, Robert <<Hi Robert, This depends on the corals you want to keep and the color of light that appeals to you. The 50/50 is going to be more balanced with white.  Most 20K's are pretty blue. It depends if you like more blue or more white.  To get good balance many people use a combination. The intensity of the light is more dependent on wattage than color so it is more important for the corals to get the wattage that best approaches the intensity of MH than color.  The color is mostly for you and your preferences. I hope this helps, Craig>>

Marine Lighting Hi <<Hi Erin, Craig answering for the crew while they play at MACNA.>> I have been going through all your lighting FAQ since I found this site - very helpful for a novice.  Thanks!  I am getting ready to set up my first tanks - 2 130 gallon, 42x24x30 deep.  In the first tank I want to create a Florida Gulf of Mexico microcosm, including Christmas tree worms and live rock and sand from that area, as well as sponges (hopefully), corals and fish and inverts common to that area.  In the second, I am pretty sure I would like to go with a South Pacific type reef, although I may go with a Caribbean type.  In any event, I would like to go with MH lamps so that I can be prepared for any photosynthetic animals, but I am unsure as to which wattage to use, especially regarding the depth of the tank.  I figure the depth will allow me to house animals from various depths at the corresponding depths in the tanks - what do you think?  How many lamps?  Do I need actinics if I go with a 10,000 - 12,000 K source?  What about the acrylic brace - should I center the lamps over each opening so that I don't melt it?  Can it be melted or injured?  I have varying reports.  Finally, do you think a bunch of muffin fans will do the cooling adequately?  I sure don't want a reef fry in my tank!  Is that too risky?  (Of course, I will set up the tank with just water ahead of time to make sure, but I'd like to prepare myself for the probability of another $700 per tank!)  I do want to try to get this right the first time, and the best I can manage for my animals, etc. <<Wow!  This sounds like a blast! For a 30" deep tank you are in the 2 X 400 watt area. In my way of thinking I like deep sand beds, so I would likely add 6" of aragonite and make it 24" deep to the substrate. Now, with good reflectors you can use 250 watt MH's. I would use two fixtures centered over the openings.  Yes, the center brace can be damaged if the light is too close, etc. Your lights will likely be 8-12" off the surface of the water so heat over the tank can be dealt with using fans. I highly recommend fans in any enclosed MH fixture to maintain the proper temp. I see your e-mail addy is Tampa Bay which puts you in the heat and humidity of summer with MH lighting. You will need supplemental fans and air conditioning or a chiller may be necessary depending on how hot your house gets. You can cool a lot of room with AC for the price of a chiller or two!  The color of the bulbs is dependent on what you wish to keep and what colors you like to see.  Actinic lighting "fires" the phosphors in corals so we can see it. A very bright white tank reveals less of this coloration than a bluer look.  This is a personal preference.  You might go to several different places and see how different lighting looks  to you. 10K is a nice white look with a touch of blue.  As you go up (12k, 20K) they get more blue. Sure sounds like a nice set-up! Enjoy, Craig>>

Lighting Wattage For FOWLR Happy (???) Last Day Of Summer :( <Ah, tempus fugit, indeed> As I am about to switch my FO to a FOWLR, I am noodling around with how to upgrade my lighting. I would like to maintain coralline and grow a few inverts in my tank to make it look more natural, but yet keep the emphasis on the predators I own. Hence I am not desiring 7 watts/g to grow the most light hungry corals, but something more moderate in intensity. Note that I will have two morays in this tank, and I don't want to freak them out by making the tank too bright -- though I will have caves and overhangs for them. I am currently at 1 watt/g. What do you recommend for wattage for a 180g with these parameters, and are power compacts the way to go or will a number of simple NO tubes do??? <Maybe doubling to two watts per gallon of full spectrum fluorescent (either CFs or added fluorescents of whatever output fits) will do, be best (life is a series of compromises... in general) will serve to boost the photosynthetic aspects/life of your LR and accommodate your Muraenids. Bob Fenner> Thanks gentlemen! Steve

Re: Lighting for a 135 Thanks for your help and prompt replies Steven (or Bob, or Team WWM). I haven't been able to get back with you until now. You had asked what in particular I wanted to put in the aquarium before you could advise me on lighting. <Yes> I would like to have some maxima and crocea clams in this tank, and then pick other corals that would be compatible with the same lighting. The tank is a 135 gallon tank (72X18X24). I really light the way MH look. I was thinking about 3 175 MH but was worried that since the tank is 24" tall this might not be enough. <Since this tank is 24" deep and your desire to house clams, I would probably recommend 3 250 watt MH's. Do be sure to get good quality lamps. They make all the difference. Aqualine-Buschke, Iwasaki, and Ushio are favorites of mine.> Because of space constraints, the lights will be fairly low, but I plan on having lots of circulation/venting and there is a glass cover on the aquarium. Would this be enough light for crocea and maximas? <See notes above.> Would it be as simple as placing the clams higher up in the aquarium and putting less light requiring organisms toward the bottom? <You could do that, too.> If the 175's are not enough would it be better to add 2 96 PC actinics or switch to 3 250 MH (or both even)? I have not purchased any of the lighting yet, so I am free to take whichever road is better. I am an Electrical Engineer, and as most engineers probably do I get a lot of fun from this hobby (or obsession?) from all of the possible DIY projects. <Much cheaper and rewarding to build some of your own stuff.> Thanks again, Greg <You are welcome. -Steven Pro>

Advice Please Lighting  A hearty hello from sunny South Africa and hope you can give me advice on my question . My question concerns lighting ( Yes I know by now that topic must drive you insane ) I have read and read and read again as much as I can from your site . My set-up is as follows : 300 Litre tank , currently have 2 x daylight 10 000k Fluorescents , 1 x blue Fluorescent . I am going to be getting 2 more fluorescents. My question : What would be the best buy )9 I.e. 2 more daylights or 1 blue etc ) .  <if you have symbiotic invertebrates (corals, anemones) then more daylight is better for their health/growth. Keep only enough blue for aesthetics. If you don't keep cnidarians, then the bulb color choice is simply a matter of aesthetics for you> Also I'm thinking of putting mirrors inside my canopy for more reflection . Is this a good idea?  <not really...> Better than Aluminium sheeting ?  <a bent and polished aluminum reflector can generally reflect/refract more light. Do look into finding a parabolic reflector (like the Spider)> And lastly what corals can I keep that will thrive with this lighting , I currently have a small group of brown mushrooms they seem to be doing fine but what others ???? <the lighting is low indeed... standard fluorescents do not penetrate very deep. Look more mostly brown corals from the leather family like Toadstool, finger and cabbage leathers (Alcyoniids) and many Zoanthids will be fine too. Have you read this article?: http://www.wetwebmedia.com/marlgtganthony.htm perhaps it will be useful for species info and lighting at depth> Thank you Thank you Thank you Werner Schoeman <it is our great pleasure to help when we can. Kindly, Anthony>

Re: lighting ?s Follow up to your reply, do you think a 4-48 inch VHO's for a total of 440 watts would improve this scenario below rather the 4-36 inch for 380 watts of VHO? <It is more intense, but again it is not cost effective to get rid of perfectly good PC's lamps. I would just add more lamps, VHO if you wish.> You call called it lateral move from 260 watts of power compacts to 380 watts of VHOs. Again my main concern is to get color out of my coral that are turning brown. What I thought was VHO's were a stronger/more intense light than PCs? <I would put it the other way around, but fairly similar.> I am really afraid that metal halides would melt my hood. I called Oceanic and they wouldn't recommend MH's. They said it might even melt the plastic trim around the top of the tank. <Now they are getting a little crazy. Properly mounted MH's will not hurt your tank trim. You may not be able to mount them inside the standard canopy, but you could always build or have something built or hang pendants.> You don't think they burn as hot as VHO's? <All lights throw heat which can easily be taken care of with appropriate room temperatures and fans.> If you were to recommend MHs - do I hang them? <Many options out there, do look around.> How high off the water? <6-12" for most> Would 2-175 watt MH and 2-40 watts actinic VHOs be okay for a 21 inch deep tank? <More than enough, notice that 40 watt actinic lamps are usually NO, not VHO.> Also, I wasn't sure what you meant by "<It will make a difference, but not much and IMO not your best/most cost effective move.>" What are you referring to by IMO? <IMO is short hand for In My Opinion.> Please let me know- thanks so very much! <I would still merely add another fixture or retrofit kit. -Steven Pro>

Lighting 50/50 no Hello crew! Just a quick question I hope you can answer. I am upgrading my lighting and am going for NO fluorescents. I looked up the full spectrum ranges (5000k) but got conflicting advice. <Full spectrum refers to the spectral analysis of lamps vs. 5000K refers to the color temperature of the lamp. Sanjay Joshi has a very good, detailed explanation of the difference. His site is linked from the www.WetWebMedia.com site or could be found by a simple search.> I want a 50/50 (half actinic) fluorescent e.g. Philips Colortone 50 (f40c50). But I have read that the Philips advantage f40t12/adv50/alto) will produce much brighter light - 3250 lumens v 1915 lumens (Colortone) can you give me any advice in this as I want the blue color for my corals. <I would merely use several lamps, actinics along with full spectrum lamps until you reach the desired intensity and appearance for your animals. IME/O, you get much better results using multiple lamps vs. trying to find one perfect lamp. In most instances, you will not be able to reach anywhere near the required light intensity for corals with one NO lamp.> Thanks a lot guys from Clint <You are welcome. -Steven Pro>

Re: Yet Another PC vs. MH Query Wow, you guys are fast!! <I'm really glad I don't hear that too often outside of WWM :p > Thanks for the information.  <our pleasure> This reasoning is definitely more logical and animal oriented than basing everything on tank volume.  <exactly, my friend> I have one more question about MH lighting. Can I shine it through the glass windows on top?  <yes> How will this affect the light getting through?  <if the glass top/canopy is kept very clean, then it mostly filters out UV. Some kind of lens is in fact necessary with MH lamps> Should they be closer to the tank in this case (closer to 6" or so)?  <nope... 9-18" for MH> I'm concerned about the extra evaporation and our 2 cats!  <very interesting... I have never heard of evaporating cats. But at least in the tank, the evap can be replaced with Kalkwasser for a Ca/Alk boost> Thanks again. Jason & Karalyn Jacobs <kind regards, Anthony>

Re: Yet Another PC vs. MH Query Hi Anthony, <cheers, my friend> As I was reading this previous email, I now feel like I am being a terrible parent.  <no worries... we are all in a state of evolution as we learn. Bad parenting is continued ignorance but you instead seek to learn and grow> I have a Haddon's carpet that I have owned for a couple of years after adopting from someone.  <a fairly hardy species as anemones go> I have a 72-bow with 4-55 watt PCs. Previously, I asked about my lighting (I can't find the email, so I can't exactly recall the response), and I was told that another 2-55 watt bulbs would be better than my moderate lighting.  Oh, ya... much agreed!> The penetration is obviously not as good as a MH,  <not even remotely close> but would the addition of two more bulbs be enough to maintain my carpet's health, or should I just bite the bullet and buy some MH?  The MH would be a lot easier... but heavy feedings can actually compensate markedly if the prey is small and digestible enough in addition to being nutritive> And what do you suggest as the amount used?  <2 175-watt 10K Aqualine MH lamps run 7-10 hours daily and mounted 9-12 inches off the surface of the water> Would it be okay to use PCs and MHs at the same time?  <if you like... but there is no need for the PC's with the MH beyond aesthetics (cool actinic dusk/dawn)> Or will the amount of MH bulbs needed force me to make a choice between either MH or PC? <no need to choose... both will be nicely bright and quite attractive if you like> Kim <best regards, Anthony>

Lighting I currently have a 72 gallon bow front Oceanic tank with a plastic ABS hood designed for this bow front.-The tank is 48 inches wide. I am having a really hard time pick out a lighting set up to upgrade what I already have. I currently have a JBJ 260 watts PC. I want to upgrade to at least VHOs. <Ok... More of a lateral move than anything.> I have several soft coral and a few SPS's but would to add more SPS because of coloration. The overall reason I am upgrading is because even my soft corals are shading towards brownish hues rather their truer colors. So know my concern is coloration and I really don't want to have to add a chiller so I guess Metal Halides are out. <Not really. I believe the "MH's needs a chiller" theory to be a vast conspiracy by the makers of fluorescent lighting. They are the same ones suppressing the evidence of alien intelligent life, but that is a different story.> Is my current choice of upgrading to 4-36 inch 95 watt VHO's for total of 380 watts going to make a difference? <It will make a difference, but not much and IMO not your best/most cost effective move.> Unfortunately, the 46.5 or 48 inch bulbs won't work with my hood. I am afraid that my hood ABS plastic would melt or cause a fire hazard with Metal Halides. <That could be a possibility.> Please tell me what you think I should do to improve the colors of my corals. <If you believe your corals need more lighting, I would keep the 4-65 watt PC's and change them all to full spectrum daylight lamps and perhaps add some VHO actinics. -Steven Pro>

Increasing Lighting I was searching for CF ballast when Google came up with your website, WOW! I have had SW tanks and several ponds over the last 7 years, and EVERY article that I have seen on your site is GREAT. <Thank you!> Ok, now my question; I am getting ready to upgrade lighting on a 100 gallon salt tank (72") that started as a fish only. Now I have added and maintained several corals (soft and hard) and it is time give them the light needed to grow. Current setup is 4-40 watt bulbs (2-20,000k / 2-blue moons) running 12 hours. <Very low intensity. I have a low light reef tank, a 55 gallon tank with 4-40 watt lamps.> It has been just enough to keep the corals alive, but now I want to change the 20k's to compacts. I can't decide on 2-96 watt 10k's or 4-55 watt 10k's. <I would not get rid of any of your current lamps, just change them all over to actinics, Phillips or URI are my preference. I would then add the 2-96 watt PC's in a full spectrum lamp.> The cost is a factor, due to the fact that I am married and some how I know that she will bring it up. Oh, can I use conventional ballast (4 of them remotely mounted) if I go with the 4-55 watt bulbs. <Power compact/compact fluorescent lamps require a PC/CF ballast.> That cost thing again. Any information would be helpful. Thank you, Brian Clark <You are welcome. -Steven Pro>

Nano Reef Lighting I have a 20 gallon saltwater tank I am converting to a small reef tank. I have an eclipse hood with a Coralife actinic blue bulb and a Coralife 10,000K bulb. They are both 15 watt. I've been told, by another person with a reef tank, that this is insufficient light for invertebrates.  <no exactly... some low light inverts would do fine. Change the lamps to 2 daylights (6500-10K)...no blue actinic needed here. Mushroom anemones would be a good first choice> Would using a Coralife Magtinic bulb increase my lighting to an acceptable level? If not, could you suggest what would help. My tank is 24" long and the hood uses 18" bulbs (2). Thank you. Lyda <best regards, Anthony>

Reef Lighting Hi Bob, <Steven this morning. Bob is out of town.> Thanks for your response. Now I have this question; what will be the good lighting for my reef tank like I said 60 gallons, 18 inch tall, lights 5 in away from water. This is what I have: 2 100 watt MH's and a 660 ice cap ballast. This is my plan have 1 MH in middle and two 40 watt actinics. <I would probably use two 6,500K 100 watt MH's and two 110 watt VHO actinics, since that is what you have the ballasts for. -Steven Pro>

MH vs. PC for a tall 125g Hello to whoever's on duty, <Steven Pro right now.> Sorry to bother you with this question, but I'd like to get your opinion on how to light my tank. I have a tall 125 gallon tank, 6 feet long with a distance of 25" from the top of the water to the top of the substrate. My tank has been up for about 8 months and contains 10 fish, live rock, snails, & 1 cleaner shrimp. The fish are 1 yellow tang, 2 Heniochus, 2 common clowns, 1 neon goby, 2 yellow tail damsels, 1 yellow damsel, and 1 four-stripe damsel. I'll give away the damsels eventually and replace with something else <If you can catch them (snicker).> (e.g., royal Gramma, small group of Firefish, etc.). My tank is currently lit (somewhat) by two 40 watt NO bulbs. I'm looking towards two 96w PC's or two 175w MH's, the continued paucity being motivated by budget. <There is a world of difference between these two upgrades, the MH's are considerably brighter/more powerful.> To install the MH's into my canopy, I'll have to modify the canopy significantly just to get the UV glass 9" off. I've read through most of your archives and have a sense of preferences for brands, etc., but I'm wondering which way to go. I know that you'll likely ask what my goal is. <Correct, the key question.> My goal is to keep the coralline I have left alive and to possibly support a few easy, hardy corals down the road. What advise do you have for me? <If you want to get into corals, bite the bullet and buy the MH's now vs. buying the PC's and later replacing them, too. It is much more cost effective to buy something once. On the other hand, if this is primarily a fish tank with a few mushrooms or something and that is all you ever want, adding two 96 watt PC's would be fine. I would get full spectrum lamps and keep the two 40 watt NO fixtures as actinics.> Thanks in advance, John <You are welcome. -Steven Pro>

Re: Reef Lighting Hi there again Mr. Steven Pro, hope you still remember me. <Truthfully, I don't. We get over 40 emails per day. It is very helpful to reply so your previous emails are their for our reference and mental refreshment.> This will be my 3rd and last email. <Ok> I haven't really upgraded my lighting but I already have (3) 40 Philips Actinic 03. My problem is that I can't seem to find those 55W 6500K Daylights in any of my LFS. <If none of the local stores carry them, you can surely purchase them on-line. We have a lot of links to e-tailers on www.WetWebMedia.com.> So I was wondering if I could use those that can be bought in hardware stores. Those screw-in types labeled ac compact fluorescent lamps? <I have read of some people using these before.> I think they have those 6500K daylights but the highest wattage I saw was 50w, so would 6 of these be OK? <I cannot at this time recommend them for your primary light source. I have only read a few scattered reports of people using them, no long-term feedback as to how well they worked.> I am now dosing Calcium which is at 400ppm, Ammonia-0, Nitrite-0, Nitrate-0, Temp - 27, S.G- 1.024. I haven't got Alkalinity and pH test kit yet. Strontium and Iodine are still being added. My main/major problem now is Diatoms, since I bought flake food "Tetra Marin" which I fed my fishes 3 time a day (still have the all the clowns and damsels which I will separate when they become horrible tank mates to each other, and the Scopas tang plus a blue hippo tang). I now changed from 10% every 5 days of water change to 10% once a week. I did not saw that the flake food has "poly-phosphate" which may have accelerated the diatoms and is now killing my moon coral (3 of the polyps at the back are gone and is covered with diatoms) and corallines and covering everything. <Phosphates really do not contribute to diatom growth. Silica and iodine can both fuel diatoms. Also, I have never seen a case of diatoms killing any coral. Other nuisance algae are invasive and destructive, but my gut tells me something else is off. Phosphate itself will interfere with calcification and could be damaging your hard corals.> My 15 Astreas are outnumbered. My water now for Tropic Marin salt mix is purified water (drinking water, reverse osmosis). How can I remove the Phosphates? <First test both your source water and then your well mixed new salt water for phosphate to determine where it could be coming in from. If both test out clean, you may just be overfeeding or under skimming.> Will baking soda precipitate/remove the phosphates?. <Kalkwasser has some reported ability to precipitate out phosphate.> I stopped feeding them with flakes and got back to feeding them saltwater fish meat, zooplankton and for the corals clams, mussels and squid. I also lost all of my Euphyllias. I think its brown jelly, my 2 hammers died quickly overnight its like they rotted inside the skeleton. My frogspawn and torch also died on this within about 3 days not as fast as the hammers. And that's 4 corals lost in a week and is very frustrating, one day they were all fine, looking good and then poof, their gone. I didn't know that Brown Jelly is contagious, since all my Euphyllias are near/touching each other. <Brown jelly infection is contagious. Did you happen to see the infectious agent? It is very noticeable.> Also can I use Calcium Carbonate for adding Calcium in my reef tank? <In a calcium reactor, else calcium carbonate is not easy to dissolve in saltwater.> My Father told me he can get me a lot of Calcium Carbonate in their company since he works in a chemical company. I need some advice on Phosphate removal, Diatoms and the Brown Jelly since I want to replace my lost Euphyllias with the same Euphyllias. Thankfully none of my other corals are affected by the brown jelly. <Euphyllias are the most susceptible, IME, but other LPS corals could be at risk. I am still not sure if that is your problem, though.> Thank you very very much, sorry for the long mail and a bunch of questions since this is will be my last email, so I tried to squeeze everything here. <No worries about length nor any reason to cut off correspondence. We use these emails as a way to help people help themselves. We answer what we can and point people in the proper direction for additional enlightenment. As long as you are doing your part, feel free to continue to ask questions.> Long live and success to all of you. Ken. <Thank you kindly. You do the same. -Steven Pro>

Lighting I know this is probably been asked more than I have thought about it and is probably covered in extensive detail in your lighting section but after reading about someone's coral "panning" for lack of light I think this is true with mine as well. I did not buy them, they merely survived on my liverock with what we thought were dead coral polyps. However, now that they are here I was wondering if there is a type of light that is brighter than the standard that comes with it that will fit in the same ballast. <There are various lighting retrofit kits available from www.AHSupply.com that entail replacing the ballast and lamp sockets, but still fit in a standard aquarium light fixture.> Lighting was not next on my list a skimmer is and so I'm looking to not spend a ton on something different. <Perhaps, you may consider finding a local aquarium hobbyist that is willing and able to provide a good home for your hitchhikers.> Thanks for your help, C <You are welcome. -Steven Pro>

Lighting Question Hello to all you helpful people at WWM <<G'day, mate! JasonC here...>> Just need a few lighting questions answered if that's ok <<It's fine with me.>> I have a 100g tank 4'x2'x2' with a 33g sump and I was going to upgrade the lighting (at the moment have 2x36w +2x18w NO fluor's) I was thinking of going to 6x36w NO using 50/50 lights (maybe Philips color tone 50 or Dura vita-lite supreme if I can find them) <<Good luck on the vita-lite - Dura is no longer an entity... too bad too, these lights worked quite well.>> I was just asking if that would be enough of too much for the below tank mates <<I don't think your lighting plan would present any problem for these.>> FISH --- 2x neon gobies (oceanops) --1x flame angel (loricula)--2x tomato clowns (frenatus)--1xhippo tang (hepatus) and 2x Banggai cardinals CORALS --there are a few corals that came on my live rock --Mussids (I think)--Staghorn--and maybe an anemone. At the moment I have no fish in the tank (been set up for 3 months but letting algae grow). I have about 90 - 100lb live rock and shell substrate.  I suppose I just need a bit of help before I build a hood for the lights (if I need MH then I won't need the hood) <<You only 'need' metal halide if you are planning to keep Tridacnid clams or SPS corals. Most anything else is much less demanding.>> thanks for all the help P.S. I have a friend starting SW tank keeping soon and I recommended your site to them as the best web site I have ever found <<Glad to hear we can be of service. Cheers, J -- >>

Worms, Halogens and Condylactis Hi to you all, Anthony and Bob. Love your books. <Danke!> My wife writes to you all quite often and we appreciate all the help. I have two questions for you, myself. We have a 75 gallon reef tank (with a brand new EV 120 Aqua C which is fabulous), three 3 foot VHO Actinics. We added to the hood, 2 exterior spotlight fixtures from Home Depot with regular bulbs in an attempt to generate some shimmer. This worked.  <be sure to have a safety lens protecting this lamp from water splash or the hot bulb cold shower glass into the tank... still, a neat idea. > We could not stop there and decided to try one of the spots with a halogen spotlight. This is certainly even more pleasing to the eye but is it OK for the fish and coral? <as per above for safety, and regarding the animals... no harm, but the color is warm and may support nuisance algae growth if your nutrient levels get away from you (not likely with that sexy new skimmer though!)> The second question is about some new worms that have shown up in the tank. This tank has been up and running for 9 months and new things do still appear from all that live rock..... <yes...awesome, and wondrous!> These worms are about 1 inch in length, and white. They are in a sort of web which is also white. The web appears to be growing (it is about 2 inches long now) but not at an alarming rate. These worms seem to be staying in the web. Any ideas? DDT? hee hee. <hmmm... almost every worm species that you will ever see is harmless or Beneficial. The description does not ring a bell though. Do send a picture in the future if you can get a clear close-up.> Thanks for the help. Have a good Labor Day. Dana <thanks kindly, Anthony>

Lighting a 135g I have a few questions about lighting for a 135 gallon tank (72X18X24). I would like to have a light setup that would not limit me as to what I could put in the tank (Corals, Clams, ...). <This is truly an impossible task. You need to have an idea as to what particularly you want to keep alive before I can advise you as to what you need.> I have been thinking about going with 3 250W MH. <When you use good lamps, most "corals" in the trade would be overlit. There are some SPS and clams that would require 250 watt halides.> I have also considered 3 175 MH and either VHO or PC actinics, but am worried that the bottom would not receive enough light since it is 24" tall. <I like 175 watt halides for most applications. Again, it all depends on what you intend to keep. Corals have a very wide range of lighting needs.> Or would a setup of just VHO or PC be even better? <Depends> There are so many different combinations so I would like your opinion on what you think the best combination for this size tank is. <There are so many lighting options due to the different depths some corals have evolved to live at. If you narrow your search down, I an sure we could be of further assistance.> Thanks, Greg <You are welcome. -Steven Pro>

Reef Lighting Steven thanks for quick response on reef lighting. <You are welcome.> I have a few more questions. This is one instance where research and studying is confusing me more. <How so?> I had planned on going with PC and all set to buy a JBJ unit. Then I read that VHO was a more true blue with the actinic and corals stand out more and I am partial to a more blue cast to the water. <Ok> So now I've been reading up on and looking at sites that sell the Ice Cap retro kits and making my own hood. Here's the problem. I found a discussion board on the Oz site about reflectors in DIY hoods....all different types of materials, colors, some say you need to make the reflector shaped like an "M" above lights, some say move lights closer together. I am completely lost. IYO/E what is the best way and material to use as a reflector in DIY hoods w/ VHO. <This discussion is mostly moot, because most people use URI VHO lamps and they have their own internal reflectors built into the lamps. IMO, almost any reflector will do. The key is keeping the lamps close to the water.> I don't want to screw things up and not utilize my lights to their fullest capability and jeopardize the life in my tank. <I think you are worrying too much. This is fundamentally a hobby which you should enjoy.> Last thing, my one big issue between the PC and VHO is with PC the capability to have on/off times of actinic and daylight is included (dusk/dawn effect). But the VHO are wired in a series so it's all or none (I don't have the money to buy a $200 dimmer or another ballast). <I would not recommend the dimmer switch.> Then I read (again) that the actinic dusk/dawn effect is actually bad because the fish see blue different and it is actually a bright lite and causes undue stress. <I have heard this alleged, too.> So they said that a dimmer is the best way. Is their any truth to this I do realize it is probably an attempt to sell the dimmers)? <I would choose either PC or VHO in complete confidence that both would serve you well. Avoid the dimmers. The dawn/dusk effect is nice in my eyes, but probably not needed. If you room is very dark, perhaps setup a lamp in the same room with a timer to come on an hour early so as to not shock the fish.> Thanks for all your help, Bryan <You are welcome. -Steven Pro>

Re: newbie (mis-matching electrics, electronic ballasts and lamps) hello again <<Hi...>> can I run the actinic VHO lights on my regular 40 watt setups that I have??? <<No... they require their own, unique ballast.>> i.e. a 40 watt VHO in place of a regular 40watt bulb. <<No such animal... VHO bulbs have significantly higher output than normal fluorescent tubes. The HO in VHO means High Output.>> I am also going to bye the 10k MH you suggested thanks a lot for all your help im beginning to enjoy the hobby again now that I am on the right track <<Make sure you continue with the research and reading. Cheers, J -- >>

Re: newbie (mis-matching electrics, electronic ballasts and lamps) <<Greetings... JasonC again.>> thanks for your quick response I left out that I want to raise hard corals and the lighting and Alk. question is for that. <<Fair enough, then you know that the bulb you have is inappropriate for SPS corals.>> I cant seem to get my coralline to grow so I don't want to add frags till then. I am back to kalking at night and dosing reef supl. <<If you are not adding Kalkwasser in your top off, then you should be adding it first thing in the morning, before the lights come on. The pH of Kalkwasser is quite high [12-ish] and better to be added in the morning when the pH of the tank is naturally lower.>> but to no avail my LFS (a great store) said my lighting is not enough, <<lighting by itself won't do anything for coralline, and in fact coralline will grow just fine under fluorescent lighting alone. You need to work on your calcium and alkalinity.>> so I went to halides I run 2 -4foot - 40 watt aquarium daylight bulbs with my 175 halide the LFS said it should be enough for coralline ?????? am I correct <<No, and neither is your LFS. Your metal halide bulb is not the correct type for an aquarium or for SPS corals, and likewise your 40w fluorescent bulbs are not the correct match for a metal halide system. Consider picking up a 10,000 Kelvin German bulb for your halide system and replacing the 40w tubes with similar length VHO actinic bulbs - this is a very standard arrangement for reefers trying to keep SPS corals. Please read the following links and FAQs beyond: http://www.wetwebmedia.com/marlgtganthony.htm http://www.wetwebmedia.com/kalkh2ofaqs.htm >> thanks again <<Cheers, J -- >>

Lighting upgrade question Hello Gentleman, <cheers, mate> My 75 gallon reef tank currently has two lighting hoods on it. 1) JBJ Formosa Deluxe 4x65 PC (2 7100 + 2 10k). 2) A plain old 40w NO fluorescent with a Coralife 6700k bulb. I want to replace the 40w NO with a Custom Sea Life 2x65 PC SmartLite system. The 4x65 Formosa will remain, giving me a total of 390w of PC lighting. I have four corals in the tank: One piece if live rock covered in metallic green mushrooms, one short tentacled tongue (plate) coral, two brains -- one red and one greenish / purple. <all low to med light animals that require regular feedings (3-5 times weekly... or tiny bits daily for optimal growth> The tongue and brains are on the substrate,  <excellent and as they should be> the mushrooms are about halfway up the water column along the back of the tank. <OK> Should I be concerned with any light acclimation issues, or is this proposed upgrade 'safe' as is? <reasonably safe indeed... fluorescent lamps just don't have that much punch (good and bad) and the upgrade here is not severe> Thanks in advance. Sincerely, Mark Schwartz<do look here for further "illumination" of the subject (sheesh that was cheesy :p) http://www.wetwebmedia.com/acclimcoralslight.htm  and here: http://www.wetwebmedia.com/marlgtganthony.htm best regards, Anthony>

Lighting Hi Crew: I am about to purchase a 4ft Giesemann 2x250W Metal Halide w/PCs to hang about a foot above an Oceanic 110G (5ft long) tank. Any opinions or information on this Giesemann light would be appreciated. <I have never used one of these before, but I did a quick search for "aquarium Giesemann light" using Google and got several hits of people discussing the product.> Thanks, Rich <Best of luck to you! -Steven Pro>

Lighting (marine, Lionfish) Greetings from Colorado! I have been reading your lighting articles and FAQ's but I haven't found anything that accurately answers my questions. I have a 120 gallon tank (I believe that it's 24" deep) with Florida and Fiji live rock, and some damsels. I have recently noticed that the coralline algae has stopped growing/ spreading and has maybe even been dying in some spots. I assume this is from poor lighting. <That or could also be caused by low or consistent levels of calcium and alkalinity.> My biggest problem is that I don't have the capabilities for VHO, power compact or halide (Interpretation: I'm too poor.) <Invest in a few test kits or have a store test your water to see if your lighting assumption is correct.> Here is the second part of my question, I would also like to add a lionfish to my tank. I know that lionfish can't live in bright environments but I don't know exactly what a "bright environment" is. So here's the question, what type of lighting will sustain life in my live rock and also my lionfish?

Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: