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FAQs Lighting for Marine Invertebrates 1

Related Articles: Lighting Marine Invertebrates, Coral Lighting: what we know and what we don't know (mostly the latter) by Sara Mavinkurve
Lighting Reef Systems: Considerations, Organisms, Goals and Costs by Bob Fenner,  Acclimating Symbiotic Reef Invertebrates to Captive Lighting, Anemone Lighting, Marine Light, & Lighting, Feeding Reef Invertebrates,
Technology: Putting on the Brakes:  How much is too much? By Tommy Dornhoffer,

Related FAQs: Lighting Marine Inverts 2, Lighting Marine Inverts 3, Lighting Marine Inverts 4, Lighting Marine Inverts 5, Lighting Marine Inverts 6, Coral Lighting 1, Coral Lighting 2 Coral Lighting 3, Coral Lighting 4, & FAQs on Coral Lighting: Science/Application, Designs/Fixtures, Lamps/Bulbs, Quality, Duration & Intensity, Night-Time, Troubleshooting/Fixing, Makes/Models/Manufacturers, & Small System Lighting, Acclimating Symbiotic Reef Invertebrates to Captive Lighting, LR Lighting, Marine System LightingFAQs 2, FAQs 3, FAQs 4, FAQs 5, Actinic Lighting, Metal Halide Lighting, Fluorescent Lighting, Compact Fluorescent LightingTridacnid ClamsLighting Tridacnid ClamsSmall System Lighting, Reef Filtration, & Reef LivestockingReef Livestocking 2, Reef Feeding, Reef Disease, Reef Maintenance,

A Montipora growing under "low light" conditions in the wild

Small Marine Aquariums
Book 1: Invertebrates, Algae
New Print and eBook on Amazon:
by Robert (Bob) Fenner
Small Marine Aquariums
ook 2: Fishes
New Print and eBook on Amazon: by Robert (Bob) Fenner
Small Marine Aquariums Book 3: Systems
New Print and eBook on Amazon:
by Robert (Bob) Fenner

Coral reef tank lighting  10/2/05 Hello, I currently have a 210G tank which is 6' long x 2' wide x 31" tall Currently I have 3-150 watt HQI's with 4-96 actinic's on it. I want to be able to keep anything and everything I want as far as corals. I know I most likely need to upgrade my lighting, but it is a toss up for me as far as upgrading to 3-250 watt HQI's with 4-96 watt actinics, or 3-400 watt HQI's with 4-96 watt actinics. Being my tank is 31" deep can I get away with 3-250 watts or do I have to go 3-400 watts? again I want to be able to keep anything as far as corals go. P.S. I do have a chiller so heat isn't that much of a issue, but household current might be. Thanks, Brad <Brad, if you want to be able to keep everything and anything, I'd go with the three 400 HQI/4-96 actinics.  James (Salty Dog)>   

Lighting Choice 7/26/05 Hi, I am having a bit of trouble deciding what type of lighting I should use for my new Reef Tank.  I am setting up a 75 Gal tank with overflow and sump/refugium on an oceanic stand with 8" canopy as well.  I would like to be able to have a LPS/SPS/Clam tank.  I have been debating between two different lighting sources.  The first is a Hamilton MH/Power Compact set-up (2 - 175 Watt MH 6500K and 2 - 96 Watt PC 7100K) and the second is a Hamilton or Ice Cap fluorescent set-up (4 - 110 Watt VHO).  Both set-ups would be retrofit kits installed in the canopy.  My concern was with the heat of the MH set-up since I do not have air conditioning and do not want to purchase a chiller, but I feel that I need that type of light to run a great looking reef tank.  Would the VHO set-up be adequate enough or do I need to go with the MH/Power Compact? <Erik, I would go with the MH/PC combo, especially if you want to keep clams.  I would substitute the 6500K with 10000K bulbs.  James (Salty Dog)> Thanks Erik Poch

Lighting for one New to Corals Well I've been reading a lot and I love this site!!  I've just started out in corals. Well to make a long story short I was told by my LFS that this compact would be all I need for the corals I want. Well I just bought a hammerhead coral (Euphyllia ancora) and they said the lighting will be okay it's a 55g tank with 48in. compact 2 65 watt true actinic o3 blue and 2 65 watt 10,000k total of 260 watts I but the coral halfway up in the tank is the  lighting enough for this coral. My other corals or okay I hope! Colt coral, mushroom, pipe organ, yellow leather, flower pot and xenia's are all doing great but not so sure about that hammerhead. Thanks a lot for your help; Audrey Bowens <Should be fine, give the hammerhead time to acclimate. James (Salty Dog)>
Lighting for Corals, cont'd.
Thanks but is the 20000k {being in the blue spectrum }going to provide more lighting to reach the bottom of the tank. which is better for corals .  <Corals really prefer lighting in the 6500K which is the temperature of daylight at high noon. Some people have had trouble with algae growth with 20K's. Your best bet for coral growth are the 10K's. James (Salty Dog)>

Lighting  I have a standard 55 gallon, about 18 inches deep. My question was whether 130 watts (two 65 watt bulbs) would be enough lighting for any soft corals , and/or any types of anemones. Thanks again! <With your tank depth, I would go with four 65w tubes. As it is you only have about 2.4 watts per gallon where 4 to 5 is the norm. I run two 65w PC's in my 29 mini reef (4.5 watts/gallon) and I feel it may not be enough). With four, you would be at 4.72 watts/gallon which should be enough for all softies, anemones and some hard corals. James (Salty Dog)>

Lighting question I am sure this is one of a million times you have been asked this. <No worries Paul. MacL here with you today.> I have 100 Gallon FOWLR but will be adding my corals. For my lighting, I decided to run 4 x 65W 10000K and 2 x 65W actinic 03, all from Hellolights. I have the 4 X 10000k in one fixture toward the back of the tank and the 2 actinics in the other fixture toward the front. <I think this will work fine for LPS and some softies, I think you are going to have to be careful with the SPS.  I personally like the blue from the actinics so I like to have them at the front. Others don't like that look as well, so that's something you might want to check out before you permanently have it done.> In your infinite wisdom, I was curious as to your opinion as the  type/quantity and placement of my setup. <Good luck, MacL> many Thanks Paul

Lights and Hoods? - 8/20/03 Hello <howdy!> I have been reading a lot of your wonderful suggestions on various lighting. It seems that MH lights 10K are a common theme when trying to illuminate a tank for most inverts. <correct and fair to say... a safe choice> Also, it seems to be recommended to hang them 6-12"'s above. <yes... 9" being ideal for many for optimal spread versus intensity> My question concerns the prefabricated hood which are fan- cooled and perhaps stand three inches at best above the glass canopy. Is this a problem, say in a 46g bow tank? <hmmm... it depends on the species of invert being kept. Some will favor or tolerate it... others will suffer light shock. And the lamps have a worse spread the closer they are to the water (not maximizing light delivery). For such fixtures... simply prop them up or suspend them higher to get your 6-12"> ... and more specifically would a 175w 10k Aqualine bulb be enough for soft corals and perhaps an anemone (haddoni or bubble tip)... <it would likely be enough for either, but you must know that the anemone should not be kept in a tank with corals. Motile cnidarians (the anemones) are a recipe for disaster with sessile ones. Issues of movement, allelopathy and simply catastrophe from the inevitable walk through the reef full of corals. Anemones need species tanks> ... or should it be supplemented with a pair of NO, VHO, or PC's and if so 6500k or actinic? <only for aesthetics if you like> As always tanks a lot for the great advice. Regards, Steve <best regards, Anthony>

Lighting LPS - 12/13/04 Hey there,     I am in the final stages of planning a 125 gallon reef.  The tank dimensions are:  72x18x23 (23 inches being the height).  After reading aquarium corals by Borneman, I have decided that I would like it to house Fungiids, Faviids, Lobophyllia, Trachyphyllia, Euphyllia, and Plerogyra.  According to the author, these corals have similar light and water flow requirements (bright light, moderate current). <Be sure to feed the proper foods of the proper size. Take a look through the FAQs we have on the subject here: http://www.wetwebmedia.com/fungiidae.htm and here: http://www.wetwebmedia.com/trachyphlliidae.htm> The trouble I am having is trying to determine the proper amount of lighting.  I am leaning towards power compacts, and am trying to decide between a Coralife Aqualight hood with 4x96watts or 6x96watts. <I like the 6x96 because of depth of your aquarium> I would like to have an open area of substrate with some free living Fungiids on it. <Sounds absolutely perfect> Do you think that the 4x96watts would provide enough light penetration for this? <Maybe.....with real good conditions otherwise and a 3times a week feeding schedule there is a chance. In fact, a good chance.>  The cost of the 6x96 watts is substantially higher, but it does have the added convenience of a remote ballast, to lessen heat build-up in the canopy. <I like this choice the best of the two> Also, how would one provide bright, indirect light (as Borneman recommends for Euphyllia), <the best way to provide this type of lighting is either have a large macro algae (like some of the many algae available from your LFS or online retailer) that partially covers (not touch) the coral (Euphyllia) or a slight rock over hang. No open or direct light needed> and do you think that a yellow tang and a Kole tang would be able to coexist in a tank this size? <Hard to say but I have heard of them coexisting in large tanks.>  Thanks in advance, I will be eagerly awaiting your response.  <Thanks for your questions and being part of the WetWebMedia experience. ~Paul>

Light Acclimation Hi, I have a 18 inch deep tank with 260 watts of PC lighting. I have 4 clams and a mix of soft and hard corals . I am switching my lighting to 250 watt 20 K XM , I plan to keep the pendant 12 inches off the water. The old lights ran for 12 hours a day. What should I start off with the new light so I don't shock or burn anything. On the other hand I don't want to cut back to much, I have read so many articles it is mind boggling. Do you have a straight forward answer for this teaser? thanks Thomas Giddens  <Hi Thomas. Rather than adjusting the photoperiod, I would suggest one of the following options: Raise the new lamps an extra foot above the water and lower them by about 2" every other day to their final position. Or, you could place the lamps as they will be run and use a couple of layers of some kind of screening material. Remove a layer every few days until they have all been removed. Best Regards. Adam>

- Lighting Choices -  Thanks for your reply about calcium but I have another question about lighting for a reef tank. I am setting up a 55 gal. reef tank. I currently have a 30 gal. with soft and hard corals and a maxima clam with 2 small fish. I am looking at 130 watt power compact vs. a 260 watt power compact. Both will be 50% actinic and 50% 10,000K. Which wattage do you recommend. <The higher wattage the better, especially with that clam - 260 watts.> I would like to get metal halide lights but wife won't let me spend money for them even though they would cheaper in the long run.  Thanks, Larry  <Cheers, J -- >

Ubiquitous Lighting Questions, and the New Coral Stocking Question Hello all. As I look at your site daily for the FAQ's, I find more and more valuable information. I can not say how valuable your perspective and experience is for those in the hobby.  <Thank you!> I have had several tanks over the past few years and have gotten out and back in.  In the past my tanks have been FO. This time after taking my wife with me to our LFS she wants to have some coral. The plan is to add what you could call easier coral like star polyps and leather corals. To give a little back ground my tank is a 125 Gal with 170 pound LR for filtration and has been running for about 6 months. The lighting currently is 2 140 watt (280 total) VHO URI bulbs (1 super actinic, 1 actinic white).  I guess my first question is should I double my lighting?  <Doubling your lighting (4x 140wt VHO's) would be an excellent start, especially when you consider keeping some of the light demanding scleractinians (stony corals).> The reason for my question is about adding coral to the tank. I understand the acclimation process and about slowing increasing the lighting, but I have searched everywhere and cannot find anything about the number of coral that can be added at a single time. I know that with fish it must be very slow. Currently I have only 3 fish in the tank (2 blue damsels and 1 Sailfin). The main reason that I am asking is that I have seen several paces that offer deals when you purchase multiple corals at a time, for an example like 5 Corals for $99 or even 9 corals for $99. Since all of the places are close to my house I could pick the coral that I want. This seams like a good deal from a monetary perspective, but I am not sure if it is a good deal from a tank perspective. Can you add this many corals at one time if they are small to mediums sized or does size of the coral even matter? <Corals produce very little biological load so it would be no problem to add a large amount of coral to your tank at once. I've seen the 9 for $99.00 deal, and it definitely is a good deal. To answer your second question, size will matter, although as I stated above, corals put out such little biological load that it would be fine to add a large amount at one time. I would first make sure your tank can support corals before you go ahead and spend $100.00 on live coral. You may want to add a few easy to keep corals to your tank first, such as mushrooms, zoanthids, etc. If these corals prove to do well, you can move on to other species of coral.> Take Care, Graham Stephan WWM.com Crew Thanks for your help and perspective. I have been reading stuff from Bob since FFExpress day's and greatly appreciate his opinions his book the Conscientious Marine Aquarist is one of the best book I have read on the subject. Also I wanted to let you know that I love the Reef Invertebrates book and can't wait until the next in the series comes out.  Thanks,  Todd

Inverts for PC's I currently have 4 x 65 watt PC's running on my 72g with 95 lbs of live rock and a 6" DSB. Two 10k whites and two actinic blues are the bulbs I am using.  I've read from a few sources that this lighting may be powerful enough to keep SPS, granted you also maintain the appropriate dKH and Ca levels. Given the latter two are in place, and water quality is high, is this feasible? If not, what types of inverts would thrive best under this type of lighting? <4x 64wt Power compacts will not be able to house many species of small polyped scleractinians, especially when it comes to the genus Acropora. Under such lighting, you may be able to keep some species of Montipora digitata, Pavona cactus and Hydnophora. I wouldn't attempt keeping any corals in the genus Acropora unless you upgrade your lighting. The corals mentioned above, if kept under such lighting, will most likely show slow growth rates and will show poor coloration (which is due to increased amounts of zooxanthellae). I would first attempt a fragment of a Hydnophora, preferably one which has been captive raised in another persons aquarium. If the fragment shows good coloration and overall appearance for over 2 months, you may move into some of the corals in the genus Montipora (M. digitata is a quick growing and easy to obtain SPS). Overall, your selection is quite limited when it comes to SPS. If you're considering switching over to the dark side (keep SPS and other light loving invertebrates, such as Tridacna clams), I would recommend you upgrade to metal halides. If you have any further questions please do not hesitate to email us back.> Take Care, Graham Stephan

Different Lighting For Different Animals One last question, kind sir, well for now at least. I have read about a 14000 K and 20000 K bulb (metal halide) both of which offer lighting more in the blue spectrum allowing the corals to fluoresce. Granted these bulbs would be more appealing to the eye for most aquarists, especially if they absolutely cannot fit another fixture for actinics but do these Kelvin ratings also offer the same photosynthetic benefits and life support capabilities as the 10000 K bulb does? <Well, at the risk over-simplifying things, these bulbs provide different wavelengths, but to photosynthetic animals, they offer essentially the same benefits, helping to feed the symbiotic algae living within the animals that we keep. Frankly, if you're not dead-set on all-out growth- try the more aesthetically appealing (IMO) 14000k and 20000k bulbs. You can always switch back, after you re-acclimate the animals to the brighter lighting schemes> And, on another note, I have yellow polyps that are  under about 16- 20 inches of water under a 150 watt 10000k bulb and they don't look so good do they need more light? <I'd look at other possible factors...Re-check water conditions. Generally, these animals can thrive under many lighting schemes.10000k seems to make them more golden, and 20000k makes them more yellow. Give them good water movement, and they should be okay.> And my hermit crab anemones wont open. What kind of lighting do they need? <10,000k should be adequate in the wattage that you're using, IMO> One last thing- I have green mushroom corals on the bottom of the tank and they don't look so good either. What's the deal with them they get hit with light but not really directly... <Well, it could be more than just the lighting. Do verify water conditions, competition from other animals, etc.> If you would be so kind as to answer these questions especially the one on the light bulbs (10 K 14K 20 K) I would greatly appreciate it.  Thanks a million........Wish I could repay you...you make life easy....well for us lazy folk...... <We're glad to be here for you! Do make use of the extensive information on the site about the topics you've brought up and then some. Lots of good stuff here- more than I could provide in just this email. Good luck! Regards, Scott F>

- Reef Lighting - Hello Bob, <Not Bob today, but JasonC... greetings.> I have a 55 gal reef tank/20 gal refugium with 4 40w standard florescence and 2 55w compact florescence lights.  50/50  and actinic bulbs (URI and custom Sealife).  I want to switch over to metal halide two 10,000k or 14,000k 175w (Blueline e-ballast) and two 40w actinic florescence.  Will that be too much light? <Not really, but you will want to bring this change in lighting in slowly... more to read about this here: http://www.wetwebmedia.com/acclimcoralslight.htm > I was thinking about rebuilding my canopy and making it 8 inches instead of the 4 inches that it is right now and keep my two 4 inch fans.  I also keep my glass on for safety reasons. The tank is filled 3/4 of the way up with live rock in the back.  I have at the top Green and yellow Goniopora, pulsing xenia (red sea), green star polyp coral, yellow polyp coral, finger leather, and a finger toadstool.  In the middle I have cabbage coral, glove polyp, pagoda coral (cup), green and purple mushrooms, Ricordea mushrooms, colt coral, two toadstools, and green finger leather.  At the bottom I have snake coral, green and brown button polyps, red mushrooms, and a sebae or long tentacle anemone. I want to get into some more LPS corals and then move into SPS corals without sacrificing my existing corals with bleaching from the new light. <Do be careful with this mix... most all corals are chemical warriors, and with a tank of this size, you are going to have some fall-out if you pack it with corals.> Also if I could switch over to the new lighting can you give me some help on how to switch over without hurting the corals. (acclimating with the new light) <Read that article.> Also what bulbs should I go with (company names and Kelvin ratings) (long skinny bulbs or the fat mushroom shaped bulbs) note: I am going to run 2 48" 40w actinics (URI) <Do believe that bulb choice has more to do with what your eye prefers than anything else. Personally, I'm really fond of the light provided by the Aqualine 10k bulbs.> Cheers, Kris <Cheers, J -- >

175w MH on 180... Enough?- Happy New Year to all !!!! <Thanks, and to you too!> I have a simple question, I currently have a 180g reef that has mostly soft corals but some LPS, I would like to add some SPS and maybe a clam. My concern is my lighting. I have 3 175 watt MH 10000k lights and 2 160w 50/50 VHO's . The canopy hangs approx 8 inches above the surface of the water. Does this sound like enough light to support SPS and clams needs. <You may have trouble keeping good color (for SPS) at the bottom of the tank, but I think you should be able to get excellent growth and coloration of SPS corals near the top of the tank. As for a clam, I'd first pick up Daniel Knop's book entitled "Giant Clams" and give it a read through. You should be able to support many of these guys, but their placement will be determined by their individual lighting needs. I hope this helps! -Kevin>

Lighting Requirements for New Reef Tank 1/8/03 Hello Crew, <Hi Roy!> I have read up on much info on the WWM for the last several months and found that the more I read, the more dependent I am to this site. <Glad to hear you are finding good information!> I'm only 6 months into the hobby, my first tank approximately 130g did not fare too well in keeping hard corals.  Mainly because of the design of the tank (too tall, too narrow), by my interior designer whom value aesthetics more than anything else.  Me being very green, didn't think too much about it at the time until finding it very inconvenient to feed or even to place corals.  In the interim and spending a lot of money, I've killed off many corals, some due to handling & misplacement, some by now returned Lemonpeel, and some by pure ignorance.   <This is a common occurrence, but it is good to hear that you obviously care about the animals and want to do better.> I'm in process of setting up my second reef tank (197cm*69*75H), though I have many questions to ask, I'm going to keep this one just on lighting to keep it simple.  I'm also setting up 2 separate smaller tanks attached to the sump below and an additional refugium tank on the side of the display.  All the tanks will be linked to the display so I can opt to keep many corals and maybe non reef-safe fishes in the other tanks.  Like my first tank, it will include calk reactor, protein skimmer, ozone, PH meter, & ORP meter.  After reading, I will be skipping the UV for this tank.   <Sounds like it will be a very nice system!> Here's the question.  For the display, I'm planning on keeping mainly hard corals including open brain corals (Trachyphylliidae), swollen brain, plate corals, Euphyllidae, pearl, Calaustrea, Catalaphyllia (I must try again),  & various clams.  I understand clams need quite a bit of light but my corals may not need as much.  So based on my tank measurements (outer perimeter) with approximately 12-15 cm coral sand bed (can't get sugar fine aragonite here), how much and what kind or types of lights do you recommend?  Cost is not an issue and I want the best lights for this setup to keep my corals live and hardy. <You are correct that the lighting needs of the corals you listed are inconsistent with the lighting needs of clams, but this is not impossible to rectify.  If you choose VHO florescent lighting, you can keep the clam up high.  If you choose Metal Halide lighting, you will have to carefully acclimate some of the corals to the intense light.  175 or 250w MH are probably a good compromise, providing plenty of light for the clams, but not too intense for the corals you wish to keep.  I would probably choose to use three 175w MH with supplemental VHO's.> Since I live in Taiwan, I am accessible to many corals from mainly Indonesia.  However, not so true with good equipments and hardware since lacking numbers of true or knowledgeable hobbyists.  Many people here like myself buy and kill many corals out of just not understanding.  Your help is genuinely appreciated. <Glad to help.  Please do make much use of the site and ask as many questions as you need.  Also, I highly recommend these books:  "The conscientious marine aquarist" by Bob Fenner and "The Reef Aquarium" series by Delbeek and Sprung.> If ever any of the crew is in Taiwan, look me up.  Roy <You may get more than you bargained for from that offer, Roy.  The crew does get after all!  Best Regards.  Adam>

- What is Moderate Lighting? - Hi -- I am planning to get a 125 gal tank, 22" deep.  The corals that I'm most interested in are mostly LPS.  I also like mushrooms, zoanthids, Fungia, and a few of the soft corals.  Most of the things I like seem to be labeled moderate light.  I don't have any interest in having clams, and not much interest in SPS.  (One or 2 of the less light-demanding SPS  would be nice if my lights allowed it).  I don't want to use metal halide & am trying to decide between two PC options.  One is the CustomSeaLife PC with the built in moonlight, 4X96W.  The other is an ABS PC system with 6X96W.  Do you think 4X96W is adequate for what I want to do? <I think LPS corals should do just fine under this lighting.> Or should I go for the higher wattage? <Well, it will make things just a little brighter, wouldn't hurt... but the 4-by would do just fine.> Thanks for your help! Beth <Cheers, J -- >

Lighting Inverts (12/11/2003) Thanks Steve, <my pleasure> Drs Foster & Smith have the CSL Power Compact with Moon-Lite on sale!  I just ordered the 48" 4x65. <great> Will this be enough to support an anemone? <No> I would really like one for my maroon clownfish pair. <Do read carefully on WWM about the disadvantages an environmental impact of attempting to keep anemones. (See here:  http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/anemones.htm)   Your clownfish do not need one to thrive. Even if you get one, there is no guarantee they will adopt it.> What corals would you recommend with this light setup? <Few, if any SPS corals. Groups that include low/moderate light species are LPS, Corallimorphs, zoanthids. (Start here: http://www.wetwebmedia.com/marlgtganthony.htm)  Also, consider Eric Borneman's book "Aquarium Corals" or Julian Sprung's coral book for guidance.> Just to let you know, here is what I have for fish.  Yellow tang, flame angel, maroon clown pair, yellow damsel, Bluefin damsel, and four yellow tail damsels. <Getting crowded in there. Expect aggression as they grow. All of these fish are prone to it. Also, the Angel may nip at your corals and your feather duster.> I also have a feather duster, cleaner shrimp, coral banded shrimp, 12 turbo snails, bunch of Astrea snails, bunch of red/blue leg hermits, 3 emerald green crabs, sally light foot crab, sand sifting sea star, 2 brittle sea stars. Does my feather duster require any special "feeding?" <Target feeding is a good idea. Search WWM for info. You clearly have an affinity for inverts (as do I). You would really get a lot of great information from Bob & Anthony's Reef Invertebrates book. If I were you, I'd buy it.> I also have a bubble coral <Beautiful, but an aggressive stinger with long sweeper tentacles. Keep several inches away from other corals>, Alveopora coral <Not very hardy. Often waste away within a year, but not as bad as Goniopora. Do read up on its needs.>, and yellow polyps <Potentially toxic to you. Be careful. Search WWM for info. Also, will sting any other corals they touch> on order from liveaquaria.com. Thanks Steve. <You're welcome. BTW, I forget. Do you have a refugium. One would be quite useful here.> Daryl

Lighting for a 10 gallon reef - 12/4/03 Dear Mr. Fenner, I have had a 10 gal. reef tank for 9 months now and can't seem to find adequate lighting to suit the hardiest of invertebrates (mushrooms & anemones). <Mushrooms yes but most if not all anemones are not exactly hardy and require much aquarist interaction> I have tried using a 15W actinic03 tube with a 19W Daylight "spiral" PC (socket bulb) combo but it doesn't seem to maintain anything but the coralline and green algae that continuously grows in the tank. <The 19w is likely too orange or yellow and most of the light spectrum and energy are probably used up as heat.>  I want to upgrade to two PC bulbs what lighting option would you recommend? <Ahh, glad you asked. I really like the CSL 2x40w enclosed PC lighting system even comes with the Moonlite LED. I got mine from Marine Depot and enjoyed their service very much. Should run about 120 smackers including shipping. This is the lighting of choice for me and my two ten gallon nano reefs> Do you think the CustomSeaLife 15 - 2 x 32 W Power Compact Retrofit would be adequate? <That will work as that is what is on my ten gallon refugium, but again if you can get more light for your tank (and about the same price if not just a teensy bit more) then why not go for it?? Here is a link to the lights I am referring to: http://www.marinedepot.com/a_lt_pc_csl.asp?CartId=#pcml> I am also currently experiencing a rapid outgrow of these little weird creatures that are growing in the tank and attaching themselves on the live rock and sand. <Look kind of like some type of hydroid. Maybe even a larval stage in jellyfish. Hard to say from your sketch, but that is what it looks like.> They look like fat oval featherdusters but do not retract and are about 3mm-5mm long and growing. (see attachment for sketch) Do you know what this is? Is it bad? <Not likely bad, but keep an eye on 'em once you start getting corals> What can I do? <Likely nothing. They will probably wax and wane with you water changes and the ever changing tank parameters. Happy holidays ~Paul> Sincerely, Henry Milian

Lighting Quandary... Good morning guys!  I have a couple quick questions for you, in regards to my 20G nano.  First off, I have a question about the lighting that I can't seem to answer in spite of a lengthy search on here.  When I upgraded the lighting in my tank, I built a custom hood with 2 55W PC ballasts, with a 50/50 mix of 03/10,000K.  My livestock in regards to corals is as follows-Pulsing Xenia, Anthelia colony, yellow polyp rock, various mushrooms and a lime green Sarcophyton.  After all the time I spent building the hood, I am wondering if this is too much light for my particular set-up.  The toadstool loves the light, as do the yellow polyps both are placed near the surface, in front of the return  lines), but the mushrooms and the Xeniid/anthelia colonies just don't seem to be opening as well as they used to.  The mushrooms are a bit shrunken/pale in appearance, and although the xenia is growing, it no longer fully extends it's stalks as it used to.  I know that leathers appreciate brighter light and stronger current, as well as the polyps, but I am unsure of the particular lighting requirements of the xenia.  It is in an area of rather swift current, and I'm wondering if this may be the culprit.  Should I worry this to death, or keep as is? <Well, I agree that the mushrooms will generally not appreciate high light intensities. Personally, I would remove these animals to a separate tank which is better suited for their needs. As far as the xenia is concerned, I have seen and kept them under a variety of lighting schemes. Personally, if they are carefully acclimated to higher light intensities, I do not believe that lighting is a factor as much as water parameters, such as pH, etc. There are dozens of theories out there on what makes xenia "tick", but it's probably a combination of a number of factors, the majority of them being water-chemistry related. Sure, you could experiment with backing down the light over the xenia and gradually re-acclimating them to the brighter light...> I love the look of the strong light, but it seems as though the mushrooms and the Xeni/Anth were happier when I had a single 55 W PC fixture.  I  know this is not an ideal selection of livestock in terms of lighting, but I figured I could pull it off if I placed the light lovers close to the surface. <Well, this can work in theory- but these animals inhabit different niches in the wild, and really do best in systems dedicated to their specific needs.> As far as chemical aggression goes, am I correct in thinking these corals with the exception of the mushrooms) are fairly "peaceful" when it comes to battling with other corals? <Well, the Sarcophyton species produce literally dozens of potentially toxic (to other corals) compounds. They can be quite aggressive, so sufficient space between the Sarcophyton and other corals is imperative> I know the yellow polyps will sting other corals, but are they also guilty of releasing compounds into the water, as the Corallimorphs? <Yes they are. Parazoanthus species (the genus that these animals belong to) are capable of releasing compounds into the water that are toxic even to fishes.> I have a 10 gallon refugium/DSB and I run a small bit of high grade carbon weekly( to battle the chemical releases), along with a 2 gallon weekly water change. <Good methods to help alleviate the buildup of allelopathic compounds> I would love to hear your opinions in regards to the lighting of this particular set-up, as I feel a bit unsure here.  All I want is what is best for my livestock, as we all do.  Thank you in advance for taking the time to read this and give me your valuable two cents :) <My pleasure! I would either relocate the mushrooms to a dedicated tank, or I'd set up a "shady" area in the tank for these animals. In general, I have never been a fan of mixing these guys with other corals> P.S.-I have a green, almost yellow macro growing on my LR, and it appears to be untouched by all my grazers, including my emerald crab.  My best description is as follows-"twisty"/branching fronds, very thick/sturdy in appearance, with what appears to me as white "fuzz" on the leaf surface (rhizoids/roots?).  I also has scattered brown dots/pigment throughout the leaves, with no discernable pattern.  It is growing fast now, and spreading to other areas as we speak.  Hardly a nuisance, but nothing I want to leave unchecked.  Any thoughts would be welcomed! <I'd love to see a picture of this stuff...I could probably make a pretty accurate ID with a picture. I love many species of algae, but when it starts spreading to different areas of the tank, it's time to start thinking about what it is and how to control it...Please try to get a  pic and we can re-evaluate!> Ohhhh, and I ALMOST forgot.  One last hitchhiker ID for you reefer maniacs.  On one of my LR pieces from PA, there is a mat like encrusting coral that has sprung back to life, and although I am psyched, I would like to know what it is.  When I first received the rock, it appeared as an encrusting greenish stony color, with a honeycomb appearance to it.  It now is re-growing it's polyps, which resemble star polyps in shape, although far smaller in size(1/16 inch across).  I'm assuming it's some sort of encrusting stony coral, but I have no clue what it is.  Neat looking though, and I'm excited to see this and many other life forms coming out of my rock. <It is cool to see these kinds of animals emerge from rock! Without seeing a good picture, I can guess that it may be a form of Porites, which is a coral that is commonly found in live rock. Other possibilities include Montastrea, Goniastrea, and a few others. A good coral ID book, like Borneman's "aquarium Corals" would help you make a positive ID on this coral.> Anyways, thanks again guys...this site has helped me tremendously.  Happy holidays to you and yours... -David Conners <Glad to be of service, David! And a happy Holiday season to you! Regards, Scott F>

Lighting and Cladiella 10/18/03 I have a 72 gal reef tank with soft corals; colts, leathers and mushrooms. I have just add a small refugium with Chaetomorpha and Gracilaria.  All my softs have done very well for the last 6 months and still are. I added one Cladiella 3 weeks ago and it hasn't done well at all. It constantly has dropped over. It has never stood erect. <often a lack of adequate water flow... have you achieved 10-20X turnover in the tank?> I carefully place into he tank and have never moved it. Most of the time it has it polyps extended but every once in a while it will puff up. It is at least 6 inches from any colt.  I was told that Cladiella are a beginners coral and easily kept. I also use Phytoplex twice a week. <Hmmm... I have serious doubts about any product that is sold warm and without a date/expiration... especially food products. Do consider culturing your own phyto, or buying a product that is sold refrigerated and dated (DT's. etc)> This would be my second failed attempt with a Cladiella. I am not sure what I am doing wrong? <not sure... were they both from the same supplier?> Also, I 440 watt of PC lighting 4-55watt 03 actinic and 4-55watt 10k. I was wonder if this would be a bad thing to done or not. I was consider running 6-55 03atinincs and 2-55watt 10ks. <the heavy blue is not needed or useful other than aesthetics. Daylight 6500-10K is best> The reason I ask is because I prefer the purple look of the 03 actinics compared to bright white of the 10ks. <agreed... but the corals/zooxanthellae service on the PAR of daylight> I would not want to do this if it was bad for overall tank. Or will I get a more purple out of my 03s if I used them with 6500K instead of 10K? <I don't expect you would> Please let me know your thoughts -Ron <best of luck, Anthony>

Enough light? 10/15/03 hey I got a question for you guys I have a 65 reef tank my lighting consist of one 175 watts metal halide 10k and two sets of power compacts that are 50/50 55 watts I'm getting about 4.3 watts per gallon maybe more my question is that enough watts to start raising sps and lps corals and clams please help thank you in advance. <to succeed in the long run, you really need to resist an unnatural mix of all corals indiscriminately like LPS & SPS & Clams... especially in a small/med reef like this. Please pick a specific group or simulate a specific region or niche. At the very least, make coral selections by light needs (High light SPS and clams... medium light soft corals... low light LPS/Corallimorphs. To that end, I can say that yes, many corals will live under a single 175 watt MH over this tank. Be sure that your lights are installed properly: MH at 6-9" off water surface... fluorescents no higher than 3" off water. Best regards, Anthony>

Light Conversation... By the term "low light" how much light are we talking about. <It can be "moderate", to downright dark (as in the case of Dendronephthya)...For our purposes, it usually means not "shockingly bright" (as in two 400 watt halides over a 24 inch tall tank!> I am looking to keep lps corals (bubble, hammer, torch and the like). I currently have 130 watts of pc light and was not looking forward to upgrading. <Should be just fine for most LPS and softies. I wouldn't worry about your lighting...You can mix up different spectrum bulbs as needed/desired> Could you suggest some inverts that I can keep with my current lighting? 55 gal tank 130 wt pc light 10 gal refugium 20 gal sump 50 lbs live rock yellow tang coral beauty false Percula thanks in advance <Well, you have a variety of choices here...Consider many of the Corallimorphs, various LPS, such as Brain Corals, etc. I suggest a copy of Anthony's "Book of Coral Propagation", or Eric Borneman's "Aquarium Corals" for plenty of great information...Have fun! Regards, Scott F.>

Lighting for corals and anemones - 10/05/03 I looked and I can't seem to find the answer, I have a 75 gal for lighting I have a smart light with 2 65 watt 50/ 50 bulbs a eco system on it a 100 gal protein skimmer and a 304 canister is my lighting enough for red based anemones? <Likely not. There are many arguments for properly lighting various invertebrates, but one thing for sure, there is not enough light in you tank for invertebrate sustainability, sorry to say. To put it into perspective, I have a 20 gallon with two 65 watt 50/50s on it and can sustain a fair amount of soft corals. There is more to it than just light but again, I can easily say this is not near enough for this type of life in a 75 gallon tank. Research your inhabitants before purchasing as to know where to place, foods, and general environment, but be sure to up the lighting as well.>  Can I do coral to or need more lighting? <More light is needed even for low light corals, unless you plan to do heterotrophic corals. More research is needed. The answer is out there - Paul>

Light Conversation... Hello and thank you in advance for your help. <A pleasure. Scott F. with you today!> I want to upgrade the lighting on my 65g (36lx18wx24h). I currently have 4 36" VHO's (2-actinic & 2-10,000K). I am slowly growing many soft corals (Xenia, polyps, leathers, etc..) and a few LPS corals (torch coral, Galaxea). I have been reading your FAQ, but am a little confused because sometimes you suggest up to a 250 watt MH bulb and other times you mention not to use any MH bulbs in a tank similar to this size. I'm sure the reason has to do with the types of corals and the exact size of the tank. I would like to add  few SPS corals (Acropora), but I plan on keeping my softies. I'm leaning towards a 175watt 10,000K and keeping up my existing 2 96watt actinics and  2 96 watt 10,000K's. I sure would hate to buy the 175 watt and later wish I had the 250 watt, but on the other side I don't want to hurt the softies either. What do you think? Thanks, Jeff <Well, Jeff, the conventional wisdom says not to mix softies and SPS at all! I suppose that in a tank of this size, you could go with 250 watt halides. On my 20" tall tank, I've been using 3 150 watt HQI pendants and get amazing growth from my SPS corals. My friends tell me that I should have bought 250 watters, but the "proof is in the pudding", as they say! Go with what works for your budget and potential future animals. True, you can' have too much light, but you don't want to melt your tank, either! Your idea of 1 175watt and the actinics sounds fine to me...But it's your call! Regards, Scott F.>

Lights and Hoods? - 8/20/03 Hello <howdy!> I have been reading a lot of your wonderful suggestions on various lighting. It seems that MH lights 10K are a common theme when trying to illuminate a tank for most inverts. <correct and fair to say... a safe choice> Also, it seems to be recommended to hang them 6-12"'s above. <yes... 9" being ideal for many for optimal spread versus intensity> My question concerns the prefabricated hood which are fan- cooled and perhaps stand three inches at best above the glass canopy. Is this a problem, say in a 46g bow tank? <hmmm... it depends on the species of invert being kept. Some will favor or tolerate it... others will suffer light shock. And the lamps have a worse spread the closer they are to the water (not maximizing light delivery). For such fixtures... simply prop them up or suspend them higher to get your 6-12"> ... and more specifically would a 175w 10k Aqualine bulb be enough for soft corals and perhaps an anemone (Haddon or bubble tip)... <it would likely be enough for either, but you must know that the anemone should not be kept in a tank with corals. Motile cnidarians (the anemones) are a recipe for disaster with sessile ones. Issues of movement, allelopathy and simply catastrophe from the inevitable walk through the reef full of corals. Anemones need species tanks> ... or should it be supplemented with a pair of NO, VHO, or PC's and if so 6500k or actinic? <only for aesthetics if you like> As always tanks a lot for the great advice. Regards, Steve <best regards, Anthony>

-Lighting a 30g- hi, I just started a 30 gallon salt water tank and am thinking of going the reef route.  I keep hearing that I need more light than what I have now, which is a Marineland 120 vac 60 hz 20 watt lid and bulb. <That you do> like I said it is a30 gal  dim 30x18 1/2x12. I have about 25 -30 lbs of LR and some cleaning critters ( sally lightfoots, Mithrax crabs, hermits and snails) I've had the tank up for two weeks and trying to let it mature all my testing is within acceptable range I would like to hear your suggestions on lighting. please keep in mind that I am new to saltwater aquariums and don't quite understand all the jargon yet <Will do! First off, if this is an eclipse hood (light and filter built into a single unit) you'll need to remove it to get any reasonable lighting. I'd suggest a pair of 55 or 65w power compact lamps. Both Custom Sealife and Coralife make 30" plug-n-play units with this lighting. You'll be able to keep a wide variety of photosynthetic invertebrates, sounds good aye? Also, check out the various lighting articles in our vast inventory! Good luck! -Kevin> thank you Marty m

-Lighting an invert tank- hi bob, <How are you? Kevin here> I have a 75gallon fish/invertebrate tank-only cycled though.  its one week old and has 2 peppermint shrimp and 3 damsels. <Ooo, shrimp so soon? Tanks don't cycle in a week and you still could have a bit of an ammonia or nitrite spike, even w/ live rock and sand.>  the LFS guy ordered lights for me but they still haven't come in and I am getting nervous.  I have read the section on lighting in your book and know that I need btwn 225 and 375w.  I need 1 blue actinic and 3 full spectrum bulbs.  you also suggest an electronic ballast with dimmer/timer.   I hope this is correct so far. <Well, this setup will be fine for an invert tank w/ live rock, but you'll need more than this for most coral and anemones should you want to keep them.> here's my problem/question: I get confused when I go on lighting sites to order.  I don't know what to order.  can you give me some recommendations with specifics? <Since you have no coral or any other photosynthetic invert you don't have to be in a huge rush for lighting. I'd go with a power compact lighting system, with four 55 or 65w power compact lamps. Coralife and Custom Sea Life both make inexpensive hoods of this nature with internal cooling fans. This setup would allow you to keep a broad spectrum of coral should you want them. Otherwise a single strip with two 55 or 65w power compacts brightens things up nicely. I hope this helps a little! -Kevin> thanks, robin

Reef Lighting Decisions: UV or NO? 7/18/03 Hello <cheers> what do you thing of lighting my 90 cube reef tank with 150W 13000 MH+ Philips tl05 (spectral characteristic enclosed). <its not much light... and it is too blue/cool IMO for many popular reef invertebrates. If this is going to be a mixed garden reef aquarium, 300-400 watts of light at 7-10K would be better> how many watts of this should I use with glass filter or no <The admission of UV or not depends entirely on the species being kept... and some experimentation. Some corals need UV to maintain handsome/natural color... others are not favored by it> Stefan Fournier has written something about it in Koralle magazine 7/2001 do you know something about it, because this light has a lot of uv rays but it can simulate corals to fluorescent brightly best regards <pick your species first and do try to replicate a reef niche (shallow water sps, deep water LPS etc) for best success. Kindly, Anthony>

- 250's Too Much for Softies? - Hi guys,  Thanks for the help in the past. <Kevin here today, ready to help again!> I have a couple of lighting questions.  I have a standard 75g which houses mostly soft corals with a few LPS.  I'm currently running 6 * 65 W PC's (mix of actinic and 10000K).  The tank has been running  for over 2 years with no signs of trouble.  I'm interested in moving on to SPS so am in the process of upgrading my lights to MH.  Another big factor in this decision is having to spend almost $300 every 6 months just to change the PC lamps. <Yes, lamp changing isn't the best time of the year, but depending on what kind of PC's you're running, you may be able to safely stretch that o 8-10 months.> Regardless of what the manufacturer says, I notice a significant difference in the amount of light after the 6 to 7 month mark. <Oh, never mind, there's your answer.> Anyway, I just ordered a MH dual 500W ballast (250W*2).  After reading a bit on your site I realized that 2 250W metal halide lamps may be too much and burn some of my softies that I've grown to love (mauve finger leather, devils hand, colt, Capnella, various mushrooms, and polyps. <If you stick the lamps right on top of the water with a full 8 hour photoperiod you will, but if you simply acclimate everything to the lighting you will have no problems.> I'm thinking of going with 2 175W lamps coupled with 130W of PC actinic just because I like the blue hue in the tank.  My order may have shipped already which means I'm stuck with the 500W ballast unless I shell out the original $50 for shipping plus the additional cost to send it back then an additional $50 to get the dual 175W ballast.  Can I still use the 2 250W bulbs but mount them higher in the canopy (10" to 12"), maybe use 20K bulbs and exclude the PC actinics? <Regardless of which lamps you choose I'd start the lamps at 20+ inches off of the tank on a 2 hour photoperiod, and over the course of a few weeks, slowly changing to your normal 8-10 hour photoperiod. After that the lights can be lowered at an inch or so per day until it is at the desired height. No biggie, as long as you take it slow you won't have to worry about UV burn, active O2 poisoning, etc.> Can I use 175W bulbs in the 250W ballast or is this dangerous play?   If so will it consume just as much electricity as the 250W bulbs? <They won't work> The last questions I have involves retrofitting a 48" JBJ strip light.  I'm sure you are familiar with the JBJ Formosa 48" light.  I was thinking of removing one strip (2 PC lamps) and mounting the two MH lamps in it's place.  I would then take the acrylic/plastic lens to a glass shop and have them cut a piece of tempered glass to replace the original lens in order to shield off UV rays.  The strip light has two fans in it already.  Do you think it's worth a try or just a stupid idea. <It would melt down, don't do that!> I could keep the other 2 PC's for actinic or remove them as well depending on which bulb I use for the MH (either 1000K or 20000K).  Any advise would be appreciated. <I'd go with 10k lamps, you'll lose much of the intensity if you choose a higher Kelvin lamp. Retrofitting PC actinics somewhere will work on the blue for you.> You guys are doing a great thing for the hobby.  Reef keeping seems to be booming and you are providing a great service to both people and ultimately the animals they keep. <We hope so! Good luck with the new lighting and I wish you great success. -Kevin> Thanks, Ralph

Lighting Clams and Stonies Hi, Marion here. I have been a reef keeper for some years now, working with SO fluorescents. I am going to upgrade my lighting system this summer. I would like to start keeping hard corals and clams as well. My problem is this....I simply cannot afford Metal Halides at this time (and probably for some time to come). Is there ANYTHING I can use in it's place that will work as well for the animals I want to keep? <Some LPS and SPS corals can be kept under PC lights if kept high in the tank. I would not attempt clams. Don>

- Leather color change & bubble coral help - Hi there, I have a 29 gallon mini reef tank set up with about 20 pounds of live rock and a good thick crushed coral / live sand base.  The water quality is excellent.  The lighting is 165W provided by 3 - 55W power compacts (2 actinic, and 1- 10K). Filtration is by way of a protein skimmer and a hang on the back filter.  Two power heads - in addition to the filter returns - are used for water circulation.  I have two problems that I am unclear of and any advice would be great!   Firstly I have a green finger leather that was a neon green when I purchased it.  I've had it for about 3 months now and although it is growing (has gone from about 4 fingers to approximately a dozen) it has dulled considerably in color.  In fact, it's now a dark green.  It's also shrunk in height (but has gained width).  It's positioned closer to the top of the tank.<It was either a tad bleached when you purchased it, or it is simply increasing it's zooxanthellae concentration in it's tissues because of your lighting.> My questions about this coral are:  Is this color change normal?  Are they some how artificially "dipped" before sale to give them the neon glow?  My pet store advised me that this may happen, but was unsure.  It's a shame the color has left this animal as it was a beautiful piece when I purchased it. <Almost any coral you put into your tank will go through a color change to some extent. I would suspect that it would retain a lighter color under metal halide lighting.> Secondly I have a large pearl bubble coral with 5 "heads".  When I purchased this coral all "heads" were alive, although not fully inflated.  Since I have placed it in my tank only one of the heads has inflated fully.  Two of the remaining 4 struggle, and the other two appear dead.  My main concern is that the stalk has changed from primarily white with some coralline algae to  a dirty green.  There does not appear to be algae growing on the outside of the stalk - more so the color is within the tissue of the animal itself.  This color change now appears to be moving higher on the stalk and is entering the head regions. <Simply algae colonizing the most valued real estate on the reef: exposed coral skeleton.> What exactly is this?  Is it a disease that can be easily treated and cured?  I'd rather keep at least one of the polyps alive and not lose the entire coral if possible. <It's not a disease, just algae doing what algae does. Good luck! -Kevin>  Any help you could provide would be fantastic.  Thank you.

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

Lighting upgrade! Hey guys! I have a simple question today. I am going to upgrade my lighting soon and I would like your advice on what to add. I currently have a 65G (36wx18dx24h) reef tank with mostly soft corals and stony polyp corals, but I want to start on some hard corals after upgrading the lighting. I currently have 4x96 watt VHO (2 actinic and 2 10,000K). <FYI those 96w lamps are referred to as power compacts. VHO lamps look like standard output fluorescents and have 2 pins on each side (as opposed to 4 pins on a single side on power compacts.)> Before I purchase anything I would like your recommendations. Do you think just one (400 watt) would be OK or would two (150, 175 or 250 watt each) be better because it will spread the light more evenly throughout the tank. <That's the age old question with 3' tanks. I'd recommend a pair of 250's or 175's.> With the lighting hardware I have now and what your recommending; what mix of actinic and high output (5500K, 6000K, 6500K, 10000K, 12000K, or 20000K) bulbs do you recommend? <I'd use 10k or 6.5k lamps in combination with actinic fluorescents. A nice combination would be a pair of 250w 10k Aqualine Buschke metal halides with a pair of 3' VHO actinics. Have fun with the new lighting! -Kevin> Regards, Jeff McHenry

Reef lighting clarification for 2003 >Hi Gents, >>Pardon me, we have a few ladies offering our invaluable service as well, Fred!  ;-)  Marina is the one this morning. >Awesome site, you've been invaluable to me, and thousands of others I am sure.  My question relates to aquarium lighting, specifically reef.  I have a small 29g reef tank, which has been up for several years. The tank is the typical DSB with LR, and lightly stocked with some inverts, BTA, Ocellaris, Scooter Blenny, and several shrimp. Corals are low light Kenya's, mushrooms, and polyps.  It is lit by 2x65 PCs, 10K and Actinic. >>Sounds good to me. >I have read numerous comments by folks at WWM and respected authors like Joyce Wilkerson, and many seem to be indicating that VHO's and MH's are 'reef lighting'.  I am at a loss why PC's for relatively shallow tanks would not be considered, since they are similar/identical to VHO's in their physical makeup, and the type of light they produce.   >>I think they may have failed to qualify their statements.  Back in the day I used normal output fluorescents, and even mixed shoplights to achieve the spectral qualities needed for my T. derasa and LPS (large polyp stony--corals), with very good results.  Light intensity/brightness (measured in lumens or lux), spectral quality (what peaks of what parts of the spectrum does the particular bulb put out), and color temperature (as measured in Kelvin--as compared against sunlight) are what is important, more so than HOW it is achieved, my friend.  The type of lighting you speak of (most folks I know would choose power compacts over VHO's, btw) is generally considered "necessary" for growing particular tridacnids and, generally, SPS (small polyp stony corals).   >My understanding is that they are fluorescent lights in a physical form factor that is simply denser than standard VHO's, hence the higher output. >>Your understanding and mine are in agreement. >I am just your average novice reefer, yet my tank has produced probably 150+ mushrooms, great polyp growth, a couple of dozen Kenya frags, and my BTA has split twice, and one of its splits has recently split.   >>Oh, do share!  It's heartening to hear of success stories with the delicate cnidarians. >Am I missing something, or did I just buy an extremely well established tank? >>Nope, you're not missing something.  You're doing things VERY right, thus proving my "As much art as science" philosophy to keeping all creatures aquatic. >P.S.  This is a terrible hobby.  It's so bad that my wife is now telling -me- we need to get a much bigger tank when we buy our house shortly.... And I haven't told her yet that the other bedrooms aren't going to need pink or blue wallpaper, 'cause we're gonna be Clown breeders! >>Hooray!  Yes, it soon goes beyond anything resembling a "hobby", and can soon come under the heading of "pathology".  LOL! >Thanks for the excellent service. >>Most welcome, Fred.  And thank you for your input!  Marina

10000k Is The Way (Lighting Shallow Water Inverts) Hi, <Hi there! Scott F. in today> I have 50 gal reef tank and I am building a cabin with a metal halide light of 175watts. If I would like to keep some sunlight loving invertebrates, what is the temperature of bulb should I use (6000K ; 10000K; 14000K)? <If you're dealing with shallow water inverts, I suppose the optimum spectrum would be the 10000k> Should I put 2 actinic 30W fluorescent with it ? <Strictly an aesthetic preference...No real benefit, IMO, especially if you are using full spectrum bulbs, such as the 10000k for your primary light source> Thank you for your help!!!! Steve Timmons <My pleasure, Steve! Good luck! Regards, Scott F>

Question on reef lighting Hi have you ever heard of a Jebo hood Jebo is the name of the manufacture anyways I'm getting one for my reef it's PC 4*55 watts I'm thinking I'm going to go to 65 watts when these  burn out anyways what bulbs would you recommended for this setup of mushrooms sun polyps zoanthids and pulsing xenias? thanks JM <Jebo is a fine brand from what I have heard/read. Before you jump to 65W you need to make sure the ballast in the hood will drive them (call Jebo). I would combine 10000K and Actinic lighting above the corals you list. After that, the brand is up to you as it can be very subjective to the individual eye. I would check around at what others are using in their tanks so you can see what it looks like to you. Hope this helps Don>

Shedding A Little Light ON T5 Fluorescents Hi folks, <Hello! Scott F. with you today!> Thanks for your excellent website ... it's become daily reading and I'm in serious danger of 'late arrival' if I treat myself to a quick (ha!) look before leaving for work in the morning. <I can relate!> Can I ask a very basic question? In the near future (I hope) I'm going to treat myself to a 5' x 2' x 2' tank to replace my Rio 180. This will be for soft corals and fish... <Sounds like my kind of tank!> and so I'm going for T5 fluorescent lighting, built into the hood. My LFS makes excellent tanks, and they come complete with sliding cover glasses. Providing I keep these algae free is their impact on lighting quality (e.g. filtering out UV) to be ignored. Thanks, Brian <Good question, Bryan. I have not personally used T5's yet, but if we use some of the common "wisdom" applied to the use of VHO fluorescents, I'd venture to say that you might lose some qualities of the light (perhaps some spectral characteristics or intensity) if it is filtered by a cover glass. May be a better route to use water proof end caps and go sans cover glass. You may want to post on the WWM Forum to see what other T5 users are doing...Be sure to share your findings on this! Regards, Scott F

Need your Advice on Reef Tank Lighting After reading your Q&A I'm more confused then ever.  I have set up a reef tank using a 44 gal. Pentagon tank.  Please give advise as to 1 light which will accommodate all corals not matter which corals I decide to buy.  Tank depth is 24", widest point of tank is 30" corner to corner. <Sorry, Denise, it is simply not possible to do this. Corals are classified by light needs and mixing low light needing corals with high light needing is not recommended. The best all around lighting in my opinion is metal halide. I would think that a 10000K 175W for low to medium need corals and a 250W for high need corals. You can supplement this with actinic (PC or VHO) if you like. Write back if you have more, Don> Denise

MH lighting/ inexpensive bulbs Hi again crew! I stumbled across this web site: http://www.animalnetwork.com/fish2/aqfm/1999/may/product/default.asp Is there any validity to this article? Being a "Poor Man" myself, I'd like to save as much as I can on lighting. Especially on the over-priced higher temperature "aquarium" metal halide bulbs compared to their drastically cheaper lower temp. counterparts. Input would be great. <Some of this is alright, but some inaccurate. Blue acrylic doesn't produce blue light, it filters light and par and does not actually produce blue spectrum lighting.  Comparing Corallife bulbs is not accurate, as these bulbs are *rated* as 10K, but are neither 10K or produce the same par as comparable bulbs. They picked a weakling to compare to.  Most folks recommend Iwasaki's for growth and bluer bulbs (10K, 14K, 20K) for *appearance*.  You may also want to look into T-5 compact fluorescent bulbs as an alternative.  Try shopping our sponsors or on the web for bulb specials.  There are few good  shortcuts!  Craig>

Lighting Question Hello All, >Hello yourself! I have a lighting question for y'all.  I was reading in the MH faq's that the duration of lighting for metal halides would be in the 4 to 7 hour a day range.   >Have you also seen these? --> http://www.wetwebmedia.com/marlgtganthony.htm http://www.wetwebmedia.com/acclimcoralslight.htm http://www.wetwebmedia.com/growingcorals.htm >Also, please try the library at--> http://www.reefs.org/library  there should be some good information available there or in the forums.  (As well as our forums at--> http://www.wetwebfotos.com/talk ) I will be keeping sps, Montipora, Blue Maxima clams sitting on the sand, housed in of a 24" deep 90 gallon tank.  I will be using 2 250W 10,000K bulbs about 12 inches from the top of the water.  If the 4 to 7 hour range is correct, what should I do for the rest of the time up to the 12 hour daily lighting??   >I would suggest considering a mix of lighting that includes power compact fluorescent lighting.  With it you could include actinics that would allow you to simulate daybreak and dusk.  This will give you the flexibility to more accurately reproduce equatorial lighting (though it's difficult to reproduce all the variables of weather--cloud cover and such). Also, for shading any type of corals that may not enjoy the bright light, I see references to using vinyl screens for shading them.  Will this be okay under the heat of the light??  They won't burn up?   >Glass can also be used, I'm a bit incredulous of vinyl as I'm imagining it, too. As always thank you.  I find it amazing that you guys don't get paid for this..... Thank you,  Paul >HINT-HINT!  LOL!!  Yeah, us, too.  You're quite welcome, I hope this has been a bit helpful, and good luck!  Marina

55 gallon tank, PC 4x96 watt for corals Hi guys,   My question is short.  I have a 55 gal. tank (36''x13.5''x24'') which has been running for a year, with a 6 line wrasse, two red head gobies, with assorted hermit crabs and snails.  I am currently running 2 96 watt smart lamps.  I would like to start trying my hand at some hardy corals.  How much light do I need to upgrade too?  I was thinking of either getting a 4 tube 96 watt hood, or getting a double and continuing to run one of my singles.  Would the 4 tube system be too much?  Or could I get by with 3 tubes? Any advice would be welcome.  I'm just afraid of over lighting the tank. <Rick, you really need to research what kind of corals you want to keep. Your current lighting would be great for low light Corallimorphs (mushrooms) and some polyps/soft corals. But even the 4x96 would not be enough for some SPS corals. My recommendation would be to get a copy of Anthony Calfo's Book of Coral Propagation Vol 1 and/or Eric Borneman's Aquarium Corals. Both excellent references and reads. Good Luck, Don> Best regards, Rick

Lighting Coral 3/24/03 How much lighting do you need for a 50 gallon salt water tank that is going to have coral in it? Thank you in advance. <the light required is relative to the needs of the specific corals you will put in the tank. Various corals have various needs. Decide on your livestock first, my friend and Use this article and the links/archives at the top of the page for guidance: http://www.wetwebmedia.com/marlgtganthony.htm best regards, Anthony>

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>

Moving lights and coral - 3/24/03 Hi <Hi there. Paul swimming in to answer your questions> I wanted to move all my live rock further back instead of all in the front of the tank and wondered if moving the rock with the mushrooms on it would effect them since the colony is on a rock way at the top of the tank will it effect them? <Well it could....but mushrooms and zoanthids are very hardy......I would go for it. Take in to consideration the flow as well.> I have the sun bulb in front of the tank and actinic bulb towards the back gonna switch that to actinic in front and sun bulb in back will this hurt the mushrooms also <wait.....sounds like right now you have the sun bulb in front, where the corals are currently right? Now you stated that you are moving the sun bulb and the coral more to the back of the tank is that correct? If that is the case then this will be fine as it sounds like the coral is basically going to be in the same environment as it was in before, just further in the back of the tank right?> thanks JM

Lighting for anemone I am thinking of buying a VHO 2x75watt fixture from one of your sponsors for a 26gal tank. I want to keep a anemone.  Should I get one actinic [75watt] and one daylight [75watt] bulb or one daylight and one 50/50[75watt] or maybe two  50/50 bulbs? Thank you very much, Steve <I would recommend a captive bred/cloned bubble tip anemone. I suggest one 50/50 and one actinic blue bulb.  Get the electronic ballast (Ice Cap) to allow for future growth or the addition of a third bulb (50/50) if needed. PLEASE make sure you read all you can about anemones and their care and feeding before you adopt one!  Have fun!  Craig>

MH reef lighting I would like to thank you for all your help. This is truly a great site and all of you need to be commended for your labors. <thanks kindly <G>> I have a lighting question that hopefully you can help me with. I currently have a 75-gallon tank with 4-96 watt power compacts for lighting. I have a good growth of yellow polyps, star polyps, Xenia (growing like a weed), mushrooms (doing well in the lower light areas), Four different Zoanthids, cup coral and fish. I would like to switch to MH lighting for the aesthetics. I could also use one or two of the 96 watt PC's for a little actinic. My dilemma is choosing between double end HQI and single end MH bulbs and fixtures. What would you recommend for the animals I have listed above? <the double ended lamps are better IMO> 150 watt HQI or 175 watt SE? <HQI> How deep could I place a clam lit with a 150 watt HQI MH if the clam was centered under the light? <depends on the species of clam... derasa and Hippopus can go lower. None below 20" IMO/IME for long term success> How about a 175 watt MH? <no difference> Would 250 watt HQI be too much light for the listed inhabitants? <likely yes... or at least, more than is needed> Thanks in advance for your help. <kindly, Anthony>

Re: lights crammed together!! My plans for the tank? Well, last year when I first set it up, all sorts of plant life grew and grew, including many interesting leafed plants. Today, a year later, not a single green sprout to be found! I figured this was due to the lack of wattage. What do you think? <I think 300W would support most macro algae and plant life over a 75G (20" deep right?)> PS. I haven't changed the bulbs in this time. <If these are power compact fluorescent bulbs, they should be changed about 6-9 months> Pam PPS. I want to have a nice variety of hard and soft corals if possible, and I don't want to be hindered by lack of light. <By placing the corals at different depths you should be able to keep most Corallimorphs (mushrooms), polyps, soft, and a few LPS corals. Put the low/medium light need corals at the bottom/middle and the high light need middle/top. If you are going to keep SPS metal halide would be recommended.> By the way, the link you sent me didn't do much for providing info on covers/lights. Are you trying to tell me to do the research myself? Hmmmm. Okay! <At the top of the page are links to our site sponsors. These folks can talk to you about your needs and direct  you to an appropriate product. If you want to read our info/FAQs on lighting start here: http://www.wetwebmedia.com/marine click on Setup and toward the bottom of the setup page is info on lighting. Hope this helps. Don>

Lights crammed together!! Bingo Don!!! Great link, thank you for all you've done for me today! Pam <Great to hear, Pam. Do update me/us on how this goes, Don>

Reef Light Recommendations- mixed I'm sorry, forgot to mention it's a 125 gallon tank which right now has mostly mushrooms, colt, and a Ritteri anemone but I want to eventually try clams. <I must admit that I'm concerned to hear that the Ritteri is mixed with corals. Not only are they incompatible with regard for allelopathy (chemical aggression). But they are also incompatible regarding lighting needs (VERY high light for this anemone yet very low light for mushrooms and also fairly low for colt coral). Also... it is entirely inappropriate to mix sessile stinging animals (corals) wit a motile stinging cnidarians (the anemone). It is quite frankly a recipe for disaster in the long run. I have seen it too many times in 15 years as a merchant and a mentor. My advice is to remove the anemone to a species-specific tank. A shallow 50 gallon by a window with a single MH lamp would be excellent> Would I be better off putting the lights a little higher up? <becuase of the mixed needs of the corals and anemone, the question cannot fairly be answered... something will suffer> Also, do you know if the AB 10K bulbs are bluer than the Ushio 10K? <the new Ushios are color-corrected for green (less of it) and both have a handsome blue-white cast IMO.> I prefer a blue tint and plan on leaving the 2 96W PC actinics on as well as the three 250W MH. Does that sound feasible? <if you like a distinct blue color, consider 20K Radiums. Excessive blue... but excellent for many corals> Thanks again for all your help. Tom <best regards, Anthony>

N.O. fluorescents with corals Hi guys hope you all are doing good! I have 5 normal out put fluores (1 actinic, 1 50-50 10 000K, 3 daylight) all 36 watt bulbs, this is atop of my 55 gallon tank, could you please list corals that will do fine under this lighting, thanks, P.S- I know that Sinularia, Sarcophyton etc should do ok but I just need some more names :-) <hmmm... so many corals. On one hand... most any coral will live here... and on the other hand very few. The dilemma with fluorescent lighting is light penetration. You can tell me that you have 100 NO bulbs over this tank and I will still call it low light if you are trying to keep many corals below the top 6-10" of water. NO bulbs just don't penetrate water that deep. In answer to your question in gross terms... most Corallimorphs and Zoantharians will survive well in the top half of the tank. Very few sps clams or corals will survive at all here in the long run. And many soft corals will fare well like the mushrooms and button polyps if kept in the top half of the water. I regret that I cannot be more specific with the amount of mail we get here every day... there are several hundred corals to list! Do get a good book on the subject. Eric Borneman's Aquarium Corals has pictures on all popular species. My Book of Coral Propagation (few pics, 450 pages text) details the lighting and husbandry requirements of every popular genera of coral in the trade. If you'd care to write back with a dream list of corals, we'll help you sort it. With kind regards, Anthony>

Lighting Recommendations for a 75 Gallon Reef I am new to saltwater tanks and just ordered a 75 gallon Oceanic RR tank. I am finding out that there doesn't seem to be a short answer to the lighting question. What I would like to know is, if you had a new 75 gallon tank and you were buying lighting for it, what type of lighting would you go with? <It would all depend on what I would want to keep in the tank.> I am going to set up a reef tank (LR & LS) with inverts, a few common fish, and some common corals. I have no plans to put anything extraordinary in the tank, as I am new to all of this. Any help you can provide would be appreciated. I am going crazy in the land of MH's, VHO's, PC's, etc, etc, etc. <I wish I could be of more assistance, but all lighting needs to be tailored to the needs of the individual corals desired to be kept. There is no perfect lighting for all corals, hence the multitude of lighting options. The animals we commonly refer to as "corals" vary in their collection locations from a few feet of depth (and some of those are exposed, out of water, at low tide) to 80 feet or more. The light they are exposed to varies significantly at those different depths. First decide what you want to keep and then investigate the needs of those corals.> Thanks, Andy <Best of luck to you in your education and this hobby. -Steven Pro>

Perfect Lighting? Hi guys I have just on short question here that I'm sure you must be so tired of answering. I have read, read, and then read some more of your site but please just advise me. I currently have a 300 litre tank filled with some mushrooms and a tree coral. My lighting consists of 4 fluorescent tubes (2 x blue and 2 x 10000k white). I have decided to change to MH's and my local pet store is raising my canopy and putting in 2 x 150 watt MH's. Is this enough for most corals and should I keep my fluorescents? <There is no such thing as enough light for most corals. Lighting needs to be tailored specifically to the exact intended photosynthetic animals and plants desired. I don't know the wattage of your fluorescents, but there is a very real possibility that your current inhabitants could suffer and die from luminary shock from this switch.> Thanks guys, Werner Schoeman <You are welcome. -Steven Pro>

Clams light problem Hi there, Your fan from Turkey :-) need your help again. <cheers, my friend from afar> I have 50 gallon setup which I have Hamilton Power Compact 3*55w 10K, 1* 55w true actinic, also NO  2* Powerglo 30W and a 1* Marine Glo 30W/ Lights are 1" from the surface of the water, it doesn't have plexi or protection from the water.   <all excellent and installed properly> I have got  a clam 2 weeks ago, I believe it is Tridacna crocea Metallic blue. The clam was put in 2 inches below the water.    All seems fine, but I have noticed that the clam mantles started to have flaky burn type markings on them.  All over the mantles.  It looks like skin burns.  Since then I moved the clam down to the sand and I hope it will get better.10" below the water line <hmmm... its OK to put this clam lower, but not for too long (2-4 weeks only). The symptoms do not sound like a burn from bright lights. Excess light would cause bleaching (paling in color) from the zooxanthellae being expelled. The clam would also let go of its foot in such a circumstance and tumble to a lower/darker place. It sounds instead to me like a problem with a predator like a damselfish or dwarf angel picking occasionally at the mantle> I also have a bubble tip anemone in the same aquarium last six month  just 4" below the waterline, it always hide, it is glowing white color.  It feeds well and seemed happy with 3 ocellaris clown.  But it does not grow and the color do worry me. <yes... the white color is a problem for lack of symbiotic algae. If this occurred after you bought the anemone, we may have a light or water quality problem. If the anemone was white when you bough it however, it is unfortunately too common. Feed well (daily ) regardless, while we wait for this specimen to regain color> I douse regularly carbon, so my water is always clear. <very good> >Do you think it is the UV from the lamps ? <doubtful... little from these fluorescent bulbs>   What do you suggest for me to do?   <you can experiment with a thin glass or acrylic lens between the lights and water if you like... but is must be cleaned weekly at least> Murat Ozturan :-) :-) :-) <best regards, Anthony>

Inverts Good Afternoon, <Good evening!>     I am in the process of stocking (slowly) my Reef set-up. I have been very careful to read up on the compatibility of the fish I am adding (with each other and with the reef). <Very wise!> I don't have a lot of information on invertebrates however. I recently read a FAQ on your site regarding the mixing of inverts (differing lighting and circulation requirements). Before purchasing any of the inverts, I make a point to ask the owner of the LFS about it's hardiness (or lack thereof) and lighting but I am now seeking more information. I have a 45 gallon (tall) glass aquarium. It measures 12"W x 24"T x 36"L. If I hadn't already had the tank (from an earlier set-up) I would have gone shallower. <24" is deep. If you had a 4" or 5" sandbed it would help.> I use power compacts - two 55W blue actinics and two 55W 6750K white bulbs. This gives me approximately 5 watts per gallon. <This would be on the low end for high light animals.> My LR comes to within approximately 10-12" of the top of my tank. My lights sit directly on top of the tank. I have a tank turnover of almost 25 times <Good to hear...> per hour when I have my mechanical filter going (once a month or so) and almost 20 when it is not in use. The flow is somewhat varied. Not including the fish or the clean-up critters, I currently have a squamosa clam, a flame scallop, <I know flames are cheap and easy to buy, but they do need to be fed. Good luck keeping this one long term (as in years)...> a leather umbrella coral, a frogspawn coral, a couple of polyps and feather dusters that hitch hiked with the LR and a Red Sea Pom Pom (I assume of the Xenia family). <Heteroxenia> I have stayed away from the maxima clams and any hard corals due to my lighting and inexperience. <Another wise choice.> The pom pom, the leather coral and the frogspawn <Euphyllia divisa: One of the better hard corals for a tank like the one you describe.> are all near the top of the LR. <Good.> I have started adding Iodine with the addition of the Pom Pom. <Are you testing for the amount of iodine in the water? You really need to so the limits will stay within reason.> I have 2 questions; with the given set-up, have I introduced any inappropriate items? <I don't see anything that should cause a problem. Be careful about mixing hard and soft corals. Many hard corals from the Scleractinia family have sweeper tentacles. Don't place them close to other corals. Corals from the octocoral family use chemical weapons. Not a major problem if you have a good skimmer and use a little bit of carbon.> Do you have any suggestions or comments regarding any new additions with regard to hardiness and/or compatibility? <The choices are so numerous...I won't go there. You are making excellent choices so far. Continue your search at WetWebMedia.com> Thanks for your help. Your site is an invaluable tool. <Thank you for sending these thoughtful questions. It is our pleasure to be of service. David Dowless>

<sigh> Change in lighting required? Hi, crew...hope all is well, <yep... Bob's back from the Caribbean and all is right in the world... except for that little thingy going on in the middle east... and the starving in Africa... the plight of persecuted Chinese... Hmmm> and as always, thanks for providing this resource. <our great pleasure> OK, a little background. I have a 75g tall (24") reef tank, but due to a chiller disaster while on vacation early summer, I lost the entire tank. <ouch... sorry> Since I had to buy a new chiller anyway, I bought a larger size, and decided to upgrade my VHOs to better lighting. After reading and reading, online and elsewhere, I chose 4 55W PC Actinic, and 2 250W 10K MH. <almost certainly too much light (the 250 MH) unless your tank is exclusively clams and shallow water SPS> It seemed a lot, but others have apparently had success on 75's with that, <I disagree... ten years of world travel and I have seen these set ups appear to work for 1-3 years before corals succumb to photoinhibition, but not so many over lit tanks making it to the 5 year mark or longer with mushrooms, low light soft coral, LPS etc> and I was thinking if I ever upgraded to a larger tank I could use the lights again. <OK... but a waste of precious and expensive electricity in the meantime> Tank seemed to do OK...I went through the standard acclimation, burned the bulbs in for 100 hours before use, and worked up to 9 hours of MH over a 2 week period, with the actinics coming on 2 hours earlier and going off an hour later. <all fine> 2 months in, I had a water flow problem that killed a pair of Acropora I had at the top of the tank. The replacement pieces didn't last the week - in retrospect, it must have been due to bleaching. At around the same time, I was getting disillusioned with the lighting - the 10Ks were very, very white in the tank, even with the actinics on. <that's just an aesthetic preference. Even the 10K lamps have more blue than corals need. Higher Kelvin lamps are worse. You will go blue at the expense of coral growth and in some cases coral color (accuracy of color that is)> Several people recommended switching to 250W 20K's, and some recommended dropping the wattage to 175W. <I whole heartedly agree with that if maximum growth is not a goal and you really like blue color. 20K Radiums are beautiful lamps> However, that would have required new ballasts (and I had already invested over $400 on the icecap 250W ballasts and 10K bulbs), plus I can't find 175W 20K Radiums. So I switched to a pair of 250W 20Ks. <OK> I don't have spare ballasts lying around, so I couldn't burn them in for 100 hours, and instead went back to 3 hours of MH, and worked back up to 9 hours over a week or so. <Oh, no!!! Please say it ain't so! <G>. Really... your corals may have toughed that one out... but it was a very stressful move. Eric Borneman on ReefCentral gave an excellent and scientific explanation for how bad that is. You cannot mess with the duration of the photoperiod so severely in such a short period of time... better to pulse the lights off and on (one hour on, one hour off, etc... for the full normal photoperiod... OR... simply use my screen method (Eric agrees) mentioned at the end of this  article: http://www.wetwebmedia.com/acclimcoralslight.htm > I love the way the tank looks light-wise now, and everything seemed fine for a week or 10 days, but the corals don't seem to be doing as well. <if not surprised at all... a very stressful change> I had another Acropora die (although he was on his last legs from the flow problem), and for the replacement piece I'm using the "screen" method to acclimate, <awesome!> but even some of the LPS (bubbles towards the top, elegance at middle) don't seem to come out much anymore. <if the elegant has a conical skeleton it needs to be in the sand. Hack... even if not... under these excess MH lamps, you may need most all LPS in the bottom third of the tank anyway> And I'm worried because I'm seeing a tinge of bleaching on another Acropora. <understood and agreed> So I guess the question is, what to do now? <before I'd buy another ballast, I'd buy a PAR meter and do cautious experiments with screen to filter light. That way you can keep your fixtures for future use and the only thing you will be beat on will be the extra cost of electricity> I wouldn't be averse to dropping to 175W, but it would be another $400, require me to sell my 2 month old 250W ballasts and bulbs to help pay for it (or have my wife banish me to the couch  ), <no worries... you may end up there anyway :)> and I don't know if anyone makes a 20K 175W (I don't relish going back to 10K's because of the white light). Should I stick it out, hope stuff acclimates? <most coral are amazingly adaptive. If the electricity thing doesn't bother you, then yes... I'd be patient, use more screen and be patient> Get a screen for the entire top of the tank and acclimate everything over the next two weeks? <Yessuh> Is it too late to stop the decline of a few of the corals? <remains to be seen> Thanks for any help you can provide...    Arthur <best regards, Anthony>

moon light for spawning fishes and sighted aquatic animals Hello! <cheers> What would you suggest as moonlight. I want to have luminescence effect. What do you think about Philips Tl05 actinic 5W for example? How can I make moon cycle? I enclose spectral characteristic of TL05 <your choice of lamp for moonlight really depends on your purpose. intent. If it is mainly aesthetic, the TL05 looks very fine to me. If it is for the fishes and other sighted animals, however, (to stimulate spawning for example) then it really isn't as important. Studies have produced results (manipulating spawning cycle) with simple incandescent blue bulbs! (like colored party/holiday light bulbs!). The light is to be plugged into a rheostat and the bulb is run 24 hrs daily and made to wax and wane with the lunar cycle. You can do this manually or use a computer microprocessor to do it. I describe a very simply method in my Book of Coral Propagation for how to do this with a rheostatic light switch for a ceiling fan. A template is made to cover the switch plate and hash marks are made around the "Orbit" of the rheostat. You can then simply follow an almanac and make occasional changes on the switch dial to follow the waxing and waning moon. Best regards, Anthony>

Your Lighting Marine Invertebrates pc.  Anthony, pls see: http://www.wetwebmedia.com/marlgtganthony.htm Can you make out my suggested chg.s? Pls adapt, adopt as you see/deem fit. Either take out my bold and italicized notes, or I will later. Bob F

Re: Some images for your consideration for your pc. on MarLgtgInverts Bob, Thanks big-time for the pics. The mag is Today's Fishkeeping UK and the editor is Derek Lambert (know?). <Bizarre... I've never heard of the title (is this a Brit ed. of Akvarium Heute?), but do know of Derek from Underworld...> He first said that he had his own images but I made a hard pitch for your archives when I sent in the piece. Lets wait to hear what this fellow has to say. I really like the third picture attached for the article on your website (the full tank/stand warm color woodwork). <Okay... if you (and Steve) have interest, we've got to get you some sort of "full set" of images/scans if they can be/come of use... can copy onto DVD's (perhaps best) and send... As a matter of fact... will send this note to all... am sure Jas.C could use as well for CA... Bob F, who has a new computer with a DVD burner... no blanks as yet.>

Small Marine Aquariums
Book 1: Invertebrates, Algae
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Small Marine Aquariums
ook 2: Fishes
New Print and eBook on Amazon: by Robert (Bob) Fenner
Small Marine Aquariums Book 3: Systems
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by Robert (Bob) Fenner
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