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FAQs about Canopies, Tops and Housings for Lighting for Marine Systems 1

Related Articles: Canopies, Covers & Lighting Fixtures, Marine Light, & Lighting, Moving Light Systems, Marine System Components, Used Gear,

Related FAQs: Canopies 2, & FAQs on Canopy/Cover: Rationale, Design/Engineering, Construction, Sealing, Reflectors, Fans, Wiring, Repairing, & Marine System LightingFAQs 2, FAQs 3, Actinic Lighting, Metal Halide Lighting, Fluorescent Lighting, Compact Fluorescent Lighting,  Small System Lighting,

- DIY Canopy - Good afternoon. <Good morning.> I was wondering if someone could give me a good site with instructions for a DIY aquarium canopy. <Sure - OzReef: http://www.ozreef.org/diy/index.html > I have a 75 gallon reef tank, mostly softies, with only 1 light strip. I'm seeking room for more light and better look. I have also heard conflicting opinions on what color to paint the inside of the canopy to increase light reflection: black latex, white? <White.> What does the crew recommend? <This member of the crew says white. Cheers, J -- >

Lighting Quandary...Part II Okay, one follow up question then.  I have a canopy on my 55 gallon tank and my wife and I both really like the way this looks.  If I were to go to a pendant system, can I mount them in a canopy? <If there is enough clearance and sufficient ventilation and fan cooling, you can definitely do this. I have pendants mounted in the canopy over my reef system.> Will I need to worry about temp under my canopy and possible overheating.  (I may already have a problem since my current temps in the summer for Freshwater run in the low 80s for about 3 months.  I'm looking into fans to see if that will cool the water enough to get it back down to about 79 degrees.).  What do you think? <Well, cooling and ventilation are huge issues when mounting pendants in the canopy. My canopy was designed specifically for pendants; you may need to see if yours will work. You should allow at least 6-8 inches of clearance above the water, and a little more room for ventilation.> Thanks again for your input and support of all of us that are trying our best to learn what we need to keep these beautiful and fragile creatures in our homes and under the best possible conditions! Jeff Smith <Glad to be of service, Jeff! Good luck! Regards, Scott F.>

Fish Jumped (6/13/05) Hi there!! Great site! So far, your help has been more than appreciated! <Glad to be a part of this helpful venture. Steve Allen with you tonight.> There is my question. I had a Chalk Basslet, very active fish, great health, lots of personality and never afraid, no matter what happens! A few days ago, I left the glass cover opened for a few hours (my mistake, I know!) and the Chalk jumped out... <Sorry to hear. I've found a couple of missing fish dried up behind my tank months later myself.> I was wondering what could have made him jump out?? <Impossible to say. Spooked by something. Just happened to jump. Many possibilities.> Water quality is good, ammonia/nitrites: 0, nitrates: ranging from 10 to 20 ppm (little high...), sg: 1.025, temp.: +/-78F, water changes: every week, 5-7%... other fishes: ocellaris clown, royal Gramma (really peaceful, even with the chalk), Yellowhead Jawfish, 2 cleaner shrimps, 1 coral banded shrimp, lots of small inverts, soft and LPS corals... <All sounds fine.> I heard (or read, can't remember) that chalks don't jump out... <Any fish can jump. There is no such thing as a fish that "never" jumps, though some are certainly much more prone to do so than others.> Any idea of the reasons why he "committed suicide"?? <Again, absolutely no way to know. I'd say that anyone who has an open-top tank will eventually lose a fish.> Thank you very much!! If you need more details about my aquarium, please kept me know! Thanks!! Ivan <Consider using a piece of that plastic egg-crate stuff from Home Depot to keep fish in while allowing good ventilation and access for feeding.> To Cover or Not to Cover, That is the Question - Or Is It? Hello Crew or Eric R., <<Hello, Marina here.>> In Tuesday's (05/24/05) FAQ, someone posted a question  "Wrasse Behavior - Jumping, Freaking And Hiding (Oh My!) - 05/23/05" and in the question the writer stated that he has the top 100% covered because the wrasse likes to jump. Eric R. then responded with <Mmm...not sealed I hope...possibly covered with egg-crate or similar?>  <<Yes.>> My question is why not 100%? Why use the egg-crate? <<Actually, those are questionS, not one question. And the answer lies in a couple of areas of concern for reef aquarists. First being O2-CO2 exchange; this exchange is greatly hampered if the tank is covered in such a way as to create almost a seal. Using something that does not allow fresh air to come across the surface of the water means that this exchange won't take place here. If one is running a wet/dry trickle filter, then it's a non-issue. However, many folks have eschewed this technology in favor of that which does not encourage this exchange. The other issue has to do with heat gain, again a problem in closed reef systems. Glass not only does not allow heat to escape, it creates a greenhouse. Higher heat means lower O2 saturation. Why eggcrate? Because it is chemically inert (unlike aluminum or brass window screening), relatively inexpensive, and very easily cleaned and configured to fit any system. Neat stuff to work with, actually.>> I'm asking because I'm currently running a 100% glass covered 150gal Oceanic RR tank. What am I doing wrong now?  <<Ha! You sound like my father-in-law ("Ron!" "What'd I do now?"), and I KNEW we'd catch you! Actually, not knowing anything else about your setup we cannot say that you're doing something wrong. But if I catch you then I will. <wink> >> Thanks in advance.  Stan <<You're welcome Stan. Now don't let me catch you doing something wrong!  Marina - The One Who WILL Catch You If You're Doing Something Wrong>> 

Lights in a Canopy? Good day, I have been reading through this site for several weeks now and think that it is really a wonderful forum. Thank you to everyone that participates and shares their skill. <Welcome> I have about 30 years in freshwater and I am starting my first marine tank this year. I have a lighting question that I have not found in the archives. I built a stand and canopy for a 48" 90 gallon AGA drilled tank. The more I research lights the less I want the bulbs fixed to the top lid (retrofit kits) do you see a problem with using one of the common aluminum fixtures inside the canopy (like the Aqualight)? <Mmm, for marine use, yes... the aluminum reacts with seawater, the residue from this is toxic to livestock> There is about 8" across the back for airflow and 8" of height inside. I plan on one 4" fan as a pusher and one as an exhaust in the canopy I would prefer MH on the tank but the common thread that I am reading is that they are so hot I would (or should) be worried about them starting the canopy on fire (it is oak). <Mmm, can be fitted with a non-metallic thermal buffer, reflector behind, twixt the wood, fixture> I was able to find a manufacturer that will put six 96-watt PC bulbs in an aluminum housing. I believe this will allow me some good options for more light hungry inverts. What are you opinions on enclosing MH in a canopy? <This is posted... can be done... with cooling fans> If I go the PC route I was thinking about four 10k bulbs and two 50/50s, do you think that would allow room for growth down the road? <Also posted... I am a bigger fan of boosted fluorescent technology than metal halide in water depths (not tank note) of less than two feet... Others opinions here vary> Is lighting the most bewildering subject or do I have another surprise coming Filters seem easy by comparison? <Heeee! You'll see. Do make sure that whatever fixture you employ is resistant to marine water. Bob Fenner> 

-A Cracking Good Time- Hi. <Hello> I just upgraded to a 92 gallon corner saltwater aquarium. I purchased a Coralife compact fluorescent fixture with 2-36" long 96 watt bulbs (one actinic, one 10000K) and 2 lunar lights. <That is a good setup> My tank has a glass cover over the top of it. I put my light directly on the tank, to gain the most out of my lighting, due to the 24" depth of my tank. The light itself has built in cooling fans to keep the Daylight bulb from overheating. There is no canopy of any kind to restrict air flow. <Yes but you will have bad results without something to get that overly hot bulb from cracking your glass covers.  there should be a set of legs to hold the unit up, either with the lights or ordered separately.> My glass keeps cracking. I heard it this morning, the first time, after my light had been on maybe an hour. I went to my local glass store and had them cut me another piece, which is 1/4" thick, by the way. I came home and placed that piece on my tank, and by tonight, it is cracking again. <Hehe, I am not laughing at you but rather remembering my personal glass cracking crusades which led me to a glass filled aquarium and a lot of water on the floor... OOPS.> It is practically breaking a line from the middle to the side each time. Do I need to use some kind of legs on my light? The weight of the light CANNOT be what is doing this, for the second time, I rested the majority of the light on the sides of the aquarium. All I can figure is the heat from the light is doing this. How will raising my light up 3" effect the lighting in my tank? I am going to have live rock, maybe a few soft corals, and some anemones later on. Will this work? Why is my glass breaking? Please help... I am going crazy over this. <Yes, you have hit this one on the head so to speak.  The lights have to be elevated in order to not crack the glass.  Your tank will not suffer from the loss of 3" of height versus all the cracked glass you have.  Though do keep the glass as clear as possible or do not use a cover if you can to not limit the light from getting into the water.> <Justin (Jager)> Lights - 50/50 vs. 10K Greetings. Boy do I need to get to bed! This is such a great time though to get reading in! I have a 90 gal. With a little over 100 lbs. Live rock, some reef safe fish, and good water parameters. Skimmer, UV, sump. I already has some strip lights mounted inside the beautiful canopy my husband made for me. They are two 65 watt PC SmartPaqs (50/50). I have added two 192 watts Coralife PC (1 96 actinic, 1 96 10K). After reading that anemones would benefit better from daylight and not really actinic (did I understand my reading correctly?).  I have been considering changing out the two 65 watt PC SmartPaqs (50/50) for two 65 watt 10K's. This would give more of the daylight that the RBTA likes. I happen to have one of these as of Thursday last week. Seems adjusting well. I have thought I would keep some corals that are easy with medium lighting requirements just to add a little color and interest to the rock. Could you affirm if the Rose bulb tip anemone likes daylight better than actinic?  <Renee', you would be better off exchanging the 50/50's for the 10K's since you have a 96w actinic already. James (Salty Dog)> Thank you. Renee'  <You're welcome>

VHO/Power Compacts VS Metal Halide  By spending an outrageous amount of money in this hobby I have learned a few things that have led me to believe that the simplest way to setup and maintain a Reef tank is to stick with the basics and not to go overboard on the vast amount of equipment available (I should write a book on what not to do in the Reef hobby). <Please do> Now with that being said, I was thinking about changing my current lighting from VHO/Power Compacts, 2-VHO/White/Actinic 1-VHO Actinic & two 96W 50/50 Total of 672W to a new Aqualight Pro, which has 3-MH, 4-PC & 3-Led lights giving me 834W. I have a 135g Oceanic with Sump, Remora Pro, two Mag 9.5 Returns and 3 Tunze 6060's... <Heeeee! A larger heater and you could make this into a Spa-bath!> ...with about 300 Lbs. of Live Rock and a 3-4 inch sand bed. I would like to know before spending this kind of money if I would be gaining that much? <That much.... for...?> I understand that I am increasing the amount of wattage, but am I also gaining a "new look" within the tank that I will be pleased with? I would appreciate any advice you can give me. Art McKinney <Mmm, not possible to render subjective evaluations for others... that is, what you might be pleased with is not within my domain of assessment... Depending on what you hope to "accomplish" functionally (boost growth? Color?) or aesthetically (again, up to you), you might be better off investing your funds in... a calcium reactor... an ozonizer... perhaps with a desiccator... A new refugium... another tank! Bob Fenner>

Re: VHO/Power Compacts VS Metal Halide and The Toilet Bowl Syndrome Thank you for your quick reply, the Aqualight Pro runs about a $1000 for the lights and accessories. <Yeeikes! New idea... save this money up and come on out and stay with a bunch of the WWM Crew at our house... for a month, diving, hiking enjoying yourself in Hawaii... April... take a look for airfares... think of the enjoyment of just the anticipation...> I guess what I was trying to ask is if the light output from the Aqualight Pro would be better than the VHO lights. I am not sure what the Spectrum is for VHO's compared to Metal Halides so I am not sure if I would be gaining anymore than the wattage....Spa, funny, everyone says we should have flow within the aquarium, the sad thing is that all of my fish are plastered to the glass.  <I'll bet... AM serious re HI. Bob Fenner> 

Of VHO/Power Compacts vs. Metal Halide and Tax Returns Again, thank you for your quick reply and the invite to Hawaii....When I see my Tax return I may have to take you up on this offer:) So, are you saying that I won't notice a difference going from the VHO setup to the Metal Halides? <I can only speak/speculate for myself... I would NOT be switching... unless there is some compelling reason you have... Bob Fenner> 

Lighting question from a new guy Well I have been reading reading etc. (wonderful site to say the least) and I am now confused on what type of lighting I should get I have a 72 gal. bow frt. My goal down the line is to have a wonderful reef with fish with quite a few corals but not too much of ether. I really do not know what lights I should get???? Without getting new ones on every upgrade and more $$. Is there a good mix or only MH or pc's (e.g. Coralife has a fixture I like, but what 96 watts,,65 watts two, four bulbs) I not sure? signed AL in Canada <Keep reading Al... it's all there on WWM. Bob Fenner>

Lighting hood coating I recently made a new hood for my 75 gal tank. It has bare wood in places that may come in contact with salt water. What would be best to protect (paint) the exposed wood with? It is not just a flat surface that I can put a laminate on. Where would I find such a product. <Either an epoxy based paint or my fave, a polyurethane> Also my lighting will be a 660 IceCap (3-lamps) and a 100w MH. Should I use VHO actinic (1 or 2) and can I use GE ultra daylight lamps in place of a 50/50? What will be my best set-up for the above lighting scheme? Thanks, Spence <Depends on what you're keeping, what you want it to do. Please read here:  http://www.wetwebmedia.com/marine/setup/index.htm  skip down to the area: Lights/Lighting... and read on. Bob Fenner>

Re: lighting hood coating Thanks Bob, <Welcome> My next question is a regular polyurethane that you use to finish a kitchen table? Glossy or flat, and how many coats would I use so that it would last for years and hold up to the inevitable salt creep. Thanks again, Spence <Is the same stuff as for tables (I REALLY like this material)... the finish is up to you... comes in a rainbow of reflectivities... Check them out at Lowe's, HD... and at least two coats... maybe with a light steel-wooling tween... and don't forget some inexpensive "throw away" brushes! Bob Fenner>

Re: lighting hood coating Bob, Thanks again I was really in a conundrum(sp?) about what wouldn't be toxic to my fish and inverts. urethane it is!  Spence <Good enough for bowling alley lanes and my countertops! Beautiful, enduring, and fun to apply! Bob F>

- IceCap Wiring Information - Hello,  I was just wandering if you had a direct route to info about IceCap Industries Model 660 Electronic Ballast. Like, where the wires go and what colors... Thanks for the help! <For all information IceCap, please go here: http://www.icecapinc.com  Cheers, J -- > 

Aquarium lighting I currently have a 55 gallon tank (standard) with 4 x 55 watt PC. Two are 10000K white and the other two are 03 actinic blue. I know that this amount of light limits some types of corals I can keep, so I recently upgraded to 2 x 175 w MH. I plan on building a canopy and incorporating all of the lighting under this canopy. First of all I was wondering if you knew of any good canopy plans for such a common size tank. <Hello Corey. I'd copy one of the nicer hoods from a dealer. I would suggest a hood where the whole top opens which makes it easier to clean the tank without having to take the hood off.>  I think I am leaning towards suspending it from the ceiling to avoid having to buy a chiller. Also do you think this would be too much light?  <Definitely not too much light.>  I would like to keep lower light loving species as well (i.e. mushroom coral). Another option I was considering was taking apart my PC fixture (same one as described above) and assembling it into a hood for my 15 gal. tall sitting beside my other tank. I have some anemones and corals in both tanks that would enjoy a lighting upgrade. What would be a good way to "divvy up this light" so to speak. I also have a spare 48 in 40 watt 50/50 fixture I plan to throw in the mix. <I would use one 10K with an actinic. James (Salty Dog)>  Thanks, Corey 

Non-jumping Tank Mate for Tomato Clown - Is There Such a Thing? >OK, looking for some help finding a tank-mate for my tomato clown.  >>Oh boy, this should be fun.  >The tank is a 37g with a bunch of soft coral and 2 clams, one squamosa and one crocea.  >>I can tell you already you're going to be VERY hard-pressed to find any fish that won't suffer harassment at the fins of the tomato. Just about any fish is going to jump if pestered the way these tomato clowns can pester. >The tank has been up for over 18 months. It used to house a two-spot hog fish and a Cherub angel as well. Due to temperature issues the tank is open. Unfortunately the hogfish jumped after about 2 months. The dwarf angel jumped about 2 months ago. Very very bummed.  >>Indeed. Consider something akin to fencing around the perimeter of the tank. >Needless to say I'm in the market for a new fish. I plan on covering portions of the tank with some egg crate, but don't want to cover the entire thing for fear of making my clams (mainly the crocea) unhappy. Any suggestions on non-jumping tankmates? I've been thinking about a canary wrasse, a six-line wrasse or a royal Gramma? Thanks, - Matt >>That's really tough when you're considering wrasses - they all have a tendency to get going really fast and then WHOOSH! Uh oh, crispy critter. With that tomato, I would not go any LESS aggressive than a nice, stout Pseudochromis species. You really need to stay with fishes that will not grow large, yet not be timid as well. Stick with animals that prefer rockwork, rather than being benthic or open-water swimmers, this will reduce competition. And, as I said, consider "fencing" instead of directly covering, like what some do with Koi. Marina DIY Hood And Lighting Greetings To The Best Knowledge Base Around! I have read many of you faq's on lighting and am narrowing down a setup that is right for my pets.  I am an employee of Lowe's home improvement and naturally I have been looking through our lighting dept.  I have decided upon constructing a hood from wood to match my stand, and plan to add five fluorescent bulbs- Four 10000k Ocean Sun 32 watt T-8 and One Coral life actinic blue 40 watt T-12.  all 48" bulbs with the T-8's on a four bulb ballast, and the T-12 on a single T-12 ballast.  I had planned on mounting the ballasts in the tank stand away from the hood. <And carefully... away from where waste heat might cause troubles> This is for a 55 gallon 48"x18"x12".   <Mmm, s/b 13" wide... or my memory is bunked out... again> I have not seen much talk about using these type bulbs for corals or anemones, only the halides and other high-dollar setups.  Will my lighting plan satisfy a bubble-tip or some types of corals? Thank you for any suggestions. <Will... but "barely"... however sufficient from my point of view. As you will come to understand, you could bring to bear much more photonic energy here... but, there are downsides to driving photosynthesis... these are covered in the extreme in archived FAQs on WWM. Bob Fenner> Hood Options, Hex Tank 1.8.05 <Hello, Ryan with you today.> Ok, every time I look at your site, which is a lot, I find myself with another question; well here goes.  My 44 gal. Pentagon tank has fairly insufficient lighting, only two 15W fluorescent bulbs for a 25'' deep tank.  Problem is the hood that came with my tank is unable to support any other lighting system.  So I went to my hardware store and made my own hood out of 1/8" thick Plexiglas. I can only fit at most a 20"Lx6"W lighting system on top. <Have you considered using a MH pendant?> I only wish to boost my coralline growth, but I was thinking of the Satellite light fixtures(?), I forget the proper name at the moment, which is only 10W more powerful than what I have now, but much more light will be able to enter the aquarium. <I have used the fixtures you're thinking of.  They worked well for a moderately lit tank.> Anyways, is Plexiglas a very good material for this purpose, and if so, would the light system be flush with the Plexiglas hood, or rest above it so that the lights are approx. 3" or so above the hood. <I'd give a bit of room for air- And hands, etc.> Thank you so much and sorry for flooding your mailbox with questions.  Thanks again! <No problem!  Ryan> -David Hume Lighting for Hex I just acquired an aquarium and I am setting it up for saltwater. I'm a rookie so I'm taking my time however I should have started reading BEFORE I bought the tank! Anyway, my question is about lighting. Tank: All-Glass 35 gallon hex with 20" Fluorescent aquarium reflector, 120v, 19w, 60hz The height of the tank is 2 ft. I know I need strong lighting for live rock (3 - 4 watts / gallon) and K >=  5500 <6500K minimum> There doesn't appear to be any lighting that will fit this hood, and if not, can I make one? <Drs. Foster & Smith on line have several PC hoods that should fit on your hex.> James (Salty Dog) Thank you very much! Sincerely, Keith Rupnik

Metal Halide Lighting 12/26/04 Hi, I was just wondering how much light most the anemones need and where they would be placed. If I was to use 150 watts were would I place it???? <It depends on the anemone.  150W metal halide might not be enough for Heteractis Magnifica regardless of placement, but on the other hand, Entacmaea Quadricolor may do fine in any part of the tank.  Do look to "The Reef Aquarium Vol. 2" for good info on specific requirements.> and what is the best Kelvin rating to use with soft corals and anemones??? <This is largely an aesthetic choice.  The animals don't really care.  However, as a general rule, lower Kelvin lamps produce more usable light per watt.  Also, FWIW, the only popular aquarium lamp available in 150w is the Iwasaki 6500k (which is actually mercury vapor).  Most Metal Halide lamps are 175w.> Hi, Also just wondering how much percent of the light is lost if cover glass is used and is that percent left an efficient amount???  Thanks <I don't have statistics on how much light is lost due to cover glass.  It depends on thickness and how clean it is.  Even very clean thin glass will block a significant amount of light, so most reefers choose not to use it.  There are other reasons to avoid glass covers as well...  heat retention, less efficient gas exchange and less evaporation.  If you are worried about fish jumping, consider other options like a high sided hood, "egg crate", etc that will avoid the problems of glass, but will also keep your fish in the tank.  Best Regards.  AdamC.>

Open Top...Open For Trouble? (Concerns Over Open Top Tanks) HELLO <Hi there! Scott F. here tonight!> Whereas many aquariums have ready-made canopies, reef aquariums with  open tops offer many benefits such as better air exchange, evaporative  cooling, better lighting, etc. <True...> Perhaps this is a silly thought, but having an open top allows everyday & inevitable household dust, hair, lint, etc., greater access to enter the system. <Not a silly thought at all...A reality of this type of system.> Chemicals probably are attached to this stuff, so should carbon be run 24/7 in open top reef tanks for airborne contaminants?   Is this really a non-issue? What are your thoughts on this? Thanks James <Well, James, this is something to think about, but I would not be overly concerned about it. Airborne contaminants are a real probability, but with adequate water movement, good filtration, and a little care, there shouldn't be many problems. Common sense around the tank, such as not spraying household cleaners or smoking in the immediate vicinity of the open top will help. Activated carbon and/or Poly Filter media should be used in every system on a regular basis, IMO, as they are excellent at removing a wide range of "bad" stuff from the water. Using such chemical media is a great idea for any tank! Hope this helps! Regards, Scott F.> Using mirrors in a canopy? Hi crew- I keep saying "this is my last question", so my apologies.  My canopy  is ready for the lighting to be installed.  Are mirrors better than  polished aluminum? << Hmmm, maybe.  Harder to bend and shape.  May be easier to clean.  Not sure what I would rather use. >> Mirrors are less expensive. << Really?  I bought the reflector for my 55 gal for $10. >> I know weight is an issue.  I do not plan on taking the canopy off,  except for emergencies, etc. Would the weight of thin mirrors ( 1/8") be too  much on the sides of a 90 gallon? << Weight is an issue.  Boy that is tough.  I think the main problem is getting a properly shaped set up with mirrors. >> Should I just go with polished  aluminum?  Stainless steel?  Mylar?? << Not Mylar. Also, not steel.  I would go polished aluminum, but I also like seeing people try new things.  So if you think you can make it go well with mirrors, then do so. >> Thank you so much. <<  Blundell  >> - Canopy Completion - Hi crew - <Hi.> Hope all is well, my next step is to wire a direct hotline to you guys to save on typing. <Can it be a 900 number?> I cannot thank you and your website enough for the  information provided while upgrading my tank. Lighting is the only part I am uneasy about.  I have upgraded from  PC's to HQI halides. I have built my own canopy- and I would sleep better if I get your approval/suggestions on it- <Ok.> It's going to be a 90 gallon tank, with mixed corals, a lot of LPS and  SPS. My lighting is DIY HQI- 2-250w with Ushio 10,000K bulbs.  Since I don't really want a suntan (Irish), I will be sealing the top half of the  canopy (where the bulbs are) with 1-inch glass. <One inch? Won't that be incredibly heavy?> The bulbs will be about 10  inches off the surface when installed.  Under the glass- I will have 2-80  CFM fans blowing through the canopy.  Above the halides, I will have 2- 30  CFM fans blowing upwards. Directly above the halides will be a polished aluminum reflector. The  rest of the canopy will be coated in silver Mylar reflective covering. I installed a dual closed loop system in the canopy, but I am confident in the plumbing area.  I am kind of seeking a "stamp of approval" on my setup, and any suggestions would be helpful. <Sounds good to me. Make sure your plans to "seal the top" of the canopy and lighting don't make the canopy too heavy to maintain OR make it impossible to swap out bulbs. Other than that, it all sounds good.> The info you provide to the general public on fishkeeping is more than helpful.  You guys (and gal) have guided me through a complete overhaul of my tank. Thank You. James P Providence, RI <Cheers, J -- >

Metal Halides above water - 11/22/04 Hello, <Hey Brent!>      I have a 55 gallon aquarium that I'd like to add metal halides.  Since my canopy is 7 inches, about 6 inches off of the surface of the water, it seems through reading the FAQs that I'll have to build a custom canopy.  Can you tell me how high the canopy should be?  <Well it is more important to note how high the recommendation for halides to be above the surface of the water. I would suggest 7-10 inches above the water (minimum) and definitely incorporate a fan or two into the canopy for cooling and moving the trapped heat out of the canopy. Do search the internet (via Google, Dogpile, or Yahoo) for DIY canopies. See if there are any helpful DIY plans available. Good luck ~Paul) Thanks, -Brent

Building your own metal halide system and canopy Hi crew, I hope all is well, and if its not, I hope it gets better. I just finished building my own canopy to house my metal halide  system.  It is built out of pine.  My MH are complete DIY, with a  reflector.  Do 250 HQI's get hot enough to warrant some insulant between  the reflectors and the wood( I spent hours making it, don't want it to turn to  ashes just yet)? << I don't think so, but I would certainly have fans in there for water heat reasons, and I guess for wood heat reasons. >> Is painting the inside of my canopy white sufficient to reflect  light? << No way!  For about $10 you can buy fantastic reflectors which make all the difference in the world.  Best money you will spend on your tank. >> I also want to address everyone who asks a question to you guys.   There is a donation area to keep these guys up and running.  I figure about  1-2 dollars for every email you send to this site is more than worth it.   The information is invaluable, and it will keep them here.  I figure I have  asked about 10 questions this year, so I'll be sending them $20.  It is  expensive to run a site, so let's all chip in!!! << Well that is awful nice of you.  I think that is a little high, and I feel bad seeing you pay that much.  I think $.02 is fine (like asking for my two cents on something).  You know if you really want to, write in a question about advertising for a certain price (I have no idea how much) Cesnales will put an add for you on our site.  We appreciate the donations, and we are here to help. >> Thank you crew. James P Rhode Island <<  Blundell  >>

Building your own metal halide system and canopy continued The metal halides will have a polished reflector.  Would covering the remaining interior of the canopy with silver Mylar work? << Not really.  I did this on a tank once.  It was great for about 8 months but eventually the salt creep just ate it away.  A polished aluminum reflector is definitely the way to go, and I wouldn't worry about using anything else. If you can, just use more of it. >> Thanks again. James <<  Blundell  >> Lights, camera, fish tank! Dear Wise Ones, <That's Wise Guys to you!  Ha!> I'm setting up a 220 acrylic reef tank (72'"x24'"x30") in my living room, with sump & mechanicals directly below in basement. <Very nice.  Eliminating noise, sloshing buckets and siphon hoses form the living space dramatically increases spousal acceptance factor!> In order to accommodate the necessary lighting, I'm having a 14" deep canopy constructed. My issue: I wanted to use three 400w M.H.s plus VHO blues, but my supplier says that there will be too much heat in the enclosed canopy, even with 4'" fans (and 1/3 hp chiller).<Heat will be a concern.  Consider bumping up the number of fans and/or using an exhaust fan that will carry the heat out of the living space (into an attic or outdoors).  A 1/3 HP chiller should be adequate if you take steps to move as much heat out of the hood as possible, otherwise, jump up to 1/2.  Since you will be in the basement, you could also consider some alternatives like running your R/O input through a long coil in your sump.  This will warm the water for the R/O (improving efficiency) and cool the tank.  If you have a sump pump, the sump makes a great geothermal heat sink.  Be creative!> He recommends three 250w M.H.s and four 96w blues. This seems a little "light" on light (sorry, couldn't resist), especially for the few SPS corals I will be transferring to the new tank. Your opinion is highly valued! Patrick  <The difference between 250 and 400w MH in terms of actual light output is not that great.  If you choose 250w DE along with their super effective reflectors, the difference becomes very small.  With either 400w or 250w double ended, you will have plenty of light in the top half of the tank for just about anything.  If you go with all 400's, you may have trouble finding spots for those lower light critters like Euphyllias, etc.  Bottom line...  IMO, 400w are probably over kill unless you want to keep light demanding SPS low in the tank.  As a point of reference, I am growing Acros, Montis, etc. even low in my 24" deep tank that is lit only with four VHO's.  Good luck!  AdamC.>

Re: Questions about lighting for new tank Ok I can do the metal halide instead of the PC, I was looking at a 2X175W MH retrofit as well (costs a little more but if I can keep it cool without a chiller I'd consider it). <Fans will do the trick, you'll need to get some large ones installed in the hood to keep it cool> But I was concerned with the heat since I will be keeping it under a canopy.  Is it possible to cool the lights enough with fans that it won't raise my tank temperature and also not set fire to my wooden canopy and burn my house down?  And if I did the MH then the two VHO would most likely be Actinic correct?  <Definitely> Thanks for your previous reply and advice, Clif <Good luck Clif, MacL> Re: 75g New Reef Tank Canopy Hey Gwen, Alejandro here again asking you about the lights, probably tired of hearing my light problems, <<Naw. Don't worry about it :) I just wish I could explain things better to you, but this is a complicated subject and requires much research on your part, in order for you to make the proper decision. I hope you will keep reading!>> well I hope this is my last email about this before my purchase, yes I told you I was doing a canopy but if this is not necessary and I can buy an already-made hood with UV protection and everything and all I have to do is raise it some several inches above my tank I can get a piece of wood and raise it 12 inches or something like that would that do it? <<Yep. But you should not need to raise up a ready-made hood. If you are so concerned about heat, you should look into buying hanging pendant-style metal halides. The pendants come with protective acrylic lenses and you can hang them at any height you wish...usually about a foot above the tank. They look great. And if you buy 10k bulbs for your pendants, you will not need actinics at all. Just the metal halides. You can buy 175w, 250w or 400w metal halide pendants. If you don't like pendant shaped lights, there are also rectangular-shaped hanging metal halides, from companies like Giesemann, for example. You can do a web search to find more companies or even mail-order them on the Net. I can't recall any offhand. For a four foot long 75g tank, I would recommend two pendants, 175w -250w each. Again, it really depends on what livestock you plan on keeping.>> Or buying that same kit but in retrofit and making a canopy? Down here its hard to get good things done like you get up there or people you can trust to help you, it's all about the money and getting it out of the way. <<It's like that everywhere...you are wise to ask your questions here.>> And it's my money in jeopardy, not theirs, that's why I look for your help. I am ready to order but just want to know which ones of those hoods will make my life easier: the one that you place on top of the tank like a Perfecto hood but raising it, my doubt is wouldn't the light spread around <<If you raise a Perfecto hood, it will spread around, so don't raise it.>> cause it won't have a canopy, this is probably better than a canopy because I don't have a chiller and more air would pass I don't know, please tell me what to do? <<Don't' raise it, just buy a canopy with a fan built into it, or hanging MH's.>> And is their any difference between the acrylic and the glass in functions of a protector for the bulbs if I get the canopy? <<Most hoods being sold today come with acrylic to protect the bulbs from salt spray, and to protect the fish and coral from UV, clean the covers often to prevent salt build-up from keeping the light from penetrating properly.>> And if  I get the hood it already comes with its UV  protector <<Yes.>> so should I remove the glass cover from  my tank because then it would be open air? <<If you like.>> also the bulbs are 5500 Hamilton's each and I could upgrade them for 10K USHIO each what do yo say? Thanks a lot. <<I am not able to compare either, I have not used these. Perhaps another member of our team can give you this information. Sorry. I DO have experience with Giesemann, though, and they really light up a tank, and make the inhabitants look spectacular. Pricy, though.-Gwen>>

Tank top/lighting question 6/9/04 hello friends!   <howdy!> just a simple one for ya': <Okey-dokey> I currently use the 1/4 inch (greenish tint) glass top that came with my tank to set my 110w pc fixture on. I have access to quality acrylic/Lexan at my work and could rout it to size. Would making a custom top out of this material (I would most likely use 3/16 or 1/4 Lexan) allow more/less filtration of  light to enter the tank, or be better for it's inhabitants? Hmmm... yes. There are two things at odds here: light admission in general, and UV admission specifically. Glass or Lexan will have various admissions of these two params. Many/most that allow  a lot of light in still often reduce UV severely (not good for corals). You need to see the mfg specs top decide on any of these random products> I want to maximize my lighting obviously, and don't think I'm willing to go topless for fear of "Gumdrop" the clown jumping out. thanks, I appreciate your time and willingness to help us all. Erich <always welcome my friend> 30g glass 15g sump, CAP 1800 return 4"sand -fine 40lbs live rock cs90 overflow urchin skimmer JBJ Versailles 110w pc lighting Millennium 2000 HOB filter -no media 1 Xenia (fingers pulse again.... hooray!) 4 hermits 5 small colonies of zoos 1 colony shrooms 1 small (for now) gold maroon clown 1 cabbage leather frag 1 Galaxea frag  (lots o' room) ;) 1 medium meat coral 1 banded coral shrimp 2 Turbos *will be adding more zoos and shrooms <the Galaxea, corallimorphs and zoanthids are all quite aggressive and noxious... enjoy them in this tank that specializes in them, and do resist any more of the weaker/incompatible species (like Xenia here). Best of luck! Anthony>

-Covering a reef aquarium- Hello WWM Crew. <Good evening, Kevin here> I really, really appreciate the advice you guys have given me in the past. It makes such a difference for someone like me who's just getting started with reefkeeping. <We're happy to help!> The issue I'm struggling with today is what to use to cover the 90-gallon reef tank I'm setting up. I know a lot of people don't cover their tanks at all because they don't want to reduce light for their corals and because they don't want to impede the exchange of gases. <Exactly why mine isn't covered.> These are definitely concerns for me, too, as I plan to keep sps corals. <As do I> But I also have my heart set on including a fairy wrasse in my tank, and I know what accomplished jumpers they are. <Holy crap, we couldn't be in more similar of a situation, I just landed a pair of Rhomboid fairy wrasses who I will not allow to hit the floor.> The only alternative I've seen to using a glass top is eggcrate. <Been there, tried that. I found that it lit up the entire room (light deflecting off the sides) and it would absolutely blind me as I approached the tank. I have also tried this stuff Home Depot sells called 'hardware cloth'. It's basically chicken wire w/ 1/2" squares covered in a green plastic and does not seem to make much of an impact on the lighting situation. Lately I have been doodling some plans for an acrylic frame about 2-4" wide that will fit into the groove in the top bracing of the tank where I would string fishing line through holes space 1/2" apart across each side. You would end up with a nice clear net that would keep fish in and allow for proper gas exchange and light penetration. I would also look into pond netting, as they may have some types that are clear.> My main concern with eggcrate is that it seems like the plastic grid would block a certain amount of light. Do you have any thoughts on that? My lighting will consist of four T5 fluorescent bulbs (100W each) and one 175 MH pendant, all suspended about 9 inches above the tank. In doing a little internet research, I did find an eggcrate product made for photography lighting which is actually supposed to diffuse and slightly intensify the light as it passes through the grid. The individual squares are apparently coated with some sort of reflective material -- possibly aluminum, but I'm not sure yet. Sounds interesting, but it's quite expensive (about $200 for 2' x 3')<Yikes, you're not kidding. Who knows how fast it will degrade w/ the saltwater splashing on it.>, and I'm afraid that the reflective material could be toxic in saltwater. <A possibility> Since the eggcrate would sit right on top of the tank and would likely be splashed from time to time, the toxicity issue makes me nervous. Are there any other alternatives I haven't thought about? <Check out my comments above, that should give you something to go on. I hope my rambling has been of some use, -Kevin> Thanks for your help. Don't know what I would do without you guys.   

Covering Reef Tank Follow-up? >Thanks so much for the advice -- I never would have thought about the glare off the eggcrate.   >>I wish I knew who helped you previously, I'd put this in their folder.  Glad whoever it was helped. >I think I'm going to try your acrylic frame with netting solution.  There's actually a plastics store a couple of blocks away from my apartment that does custom orders.   >>So and so will be glad to hear it.  Marina

-Covering Reef Tank Follow-up- <Wow, looks like you get both Marina and Kevin in this one, I hope you can handle it!> >Thanks so much for the advice -- I never would have thought about the glare off the eggcrate. <Neither did I, that is until I was blinded by it. It also seems to visibly cut down on the light, since the eggcrate is about 1/4" deep> >>I wish I knew who helped you previously, I'd put this in their folder. Glad whoever it was helped. <Me me me!> >I think I'm going to try your acrylic frame with netting solution. There's actually a plastics store a couple of blocks away from my apartment that does custom orders. >>So and so will be glad to hear it. Marina <Do send pictures if you finish it!!! I've yet to start it myself, and would love to see how yours comes out! -Kevin>

-Covering Reef Tank Follow up to the Follow-up- >Will do.  By the way, I'm having some free samples of PVC netting sent to me from a company called Internet (at www.internetmesh.net).   >>Oh, really?  How'd you find this place?  Is it resistant to UV and heat?  This may be a good solution for a LOT of people. >I'm told the "squares" in the netting samples I'm receiving range from 1/4" to 1/2".  If the netting is clear or at least very thin, it may also work well in a frame over the tank.  If it turns out to be good stuff, I'll let you know.  Thanks again, Kevin. >>Absolutely please do.  Marina WWM FAQ Crew <crew@mail.wetwebmedia.com> wrote:-Covering Reef Tank Follow-up- >Thanks so much for the advice -- I never would have thought about the glare off the eggcrate. >>I wish I knew who helped you previously, I'd put this in their folder. Glad whoever it was helped. >I think I'm going to try your acrylic frame with netting solution. There's actually a plastics store a couple of blocks away from my apartment that does custom orders. >>So and so will be glad to hear it. Marina

DIY Canopy pt. 2 Since you are building a canopy yourself I must ask what you will use for lighting? <My canopy on this setup I'm building is 6 60 inch VHO Tubes and variable moonlighting.> I plan on keeping soft and hard corals. Which bulbs would you use if you had my set up. A 125 gallon tank with 2 inch sandbed, two 250 watt HQI fixtures with 4 55 watt pc's. I have the fixtures but haven't bought the bulbs yet. <I like Coralife for the PC, Aqualine AB for the halide> Will this be adequate lighting? <Oh yes> I am stumped on whether I should use 10,000k metal halide bulbs and supplement the actinic with the pc bulbs. Or use a 14,000k or 20,000k bulb in the halides. I think most of this is preference as I do like the blue light but I want the corals to get enough light. <Which corals, that's really the question. The tank I'm building is a propagation tank for Sinularia and Ricordea- Heavy on the blues. Depends on the animal, or go with a balanced approach if you'd like a wide range of choices. I'd go 10,000k HQI Aqualine with 4 55 watt PCs, all actinic.> I am stumped at how I can mount the pc lights closer to the water than the halides as well. I've read the general rule of thumb is mounting the halides 10 to 12 inches away and the pc's 3 to 6 inches away. <Yes, the PCs are fairly cool to the touch.> I have never used the metal halides and I do worry about the heat they generate. <Lots! 2 250's will generate a serious amount of heat> I plan on using fans for sure and may be more conservative by mounting the halides 14 inches from the water. <12 is fine> There is so many things to consider, it can be a headache, LOL. <Certainly!> I'm sure it will work out in the end. I am just curious to what the pro's would do. <Ha! Just had more headaches in my time. Good luck, and let's see a picture of this tank all up and running when it's done! Good luck, Ryan> Thanks again for any info.

The Dreaded Hex!  >hello!  >>Greetings.  >first time "question asker" kind of a beginner with saltwater tanks.  Here's the dillio. I have a 30 gallon hex (was a free gift) with over 30 lbs of live rock, a wavemaker, and a filter (soon to be replaced by a protein skimmer  [SeaClone 100]), recently added a cleanup crew of some hermits and emerald and sally light foot crabs, and bubblers (do I need to get rid of those??).  >>The emerald (a.k.a. Mithrax) and Sally Lightfoots (one of three possible species), you very well may need to. Not always known for being polite customers. As for the bubblers, the salt creep they generate will help you along with your decision one way or the other.  >Well the main question I have is!! . . . what can I do for some great lighting? I don't want to do a metal halide because I plan on moving in probably 5 months  from now (or my roommate probably won't approve of how it looks hanging from the ceiling as it does) and there are no compacts that can fit with the top of the  tank being 20" across. I recently found an Aqualight Deluxe 20" exuding 96 watts. Should I just go with it or is there someone out there that can take this hex to other places than 3 watts per gallon.  >>Well, I don't see why you can't go with power compact fluorescents at all. You'll be somewhat limited as to what you can keep in terms of photosynthetic creatures, but you may be able to create a "bank" of lights, or go with the MH lights post-move anyway (5 months in terms of setting up a reef and getting it going really isn't a very long time).  >I don't really want to put in that much time making a hood with a compact. I'd rather buy another tank than do that, but are there other stories I can hear about overcoming the dreaded Hex? Can someone just make me a hood and sell it to me on eBay, please?!?!  >>I'm sure someone could, but you'd have to ask them.  >p.s. the top is glass (looks custom made) -Michael  >>Right, well, there you have it. Or, stick with entirely non-photosynthetic animals and you'll have no worries on the lighting front. Marina

Stupid Question? No..  >Hello all...let me throw a stupid question at you...  >>Hello.. if you insist.  >I replaced my current (inadequate) lighting with 4-30 watt screw-in compact fluorescent bulbs, 2 in each hood (total of 120 watts). I have a 55-gallon tank. It's a tight fit so the bulbs touch the clear plastic that separates the lighting from the water.  >>Hm, not such a good thing.  >I touched the plastic from the inside of the tank and it's quite hot. Will this melt or can the plastic handle the heat. Thanks  >>Well, it may be that the plastic can handle the heat well enough not to melt, but I would expect it to rather quickly degrade in quality such that it very well may crack, or eventually begin to melt. Either situation isn't very good. If there's any way you can lift the light fixture (maybe even some silicone nipples - the stick on kind) you would be enhancing safety/longevity. Marina

Distance from lights 3/25/04 I am building a canopy for my 90 gallon tank...I have purchased a DIY kit with 2x250 metal halides and 2x46.4 inch VHO's What would be the ideal height I would want each light from?  I have heard that the metal halides should be 6 inches and VHO's 2 or 3?  Does it really matter? <It isn't super critical.  The closer to the water you get, the more light you will get into the tank, but there are practical limits in terms of splash risk and being able to work in the thank.  The distances you stated are reasonable ideal goals, but you will likely find that a bit higher is more practical, and that is fine.  I would recommend staying within about 10" of the surface, though.  Best Regards.  Adam>

Heavy Metal In Deep Sand! Hi Crew, <Hi there! Scott F. with you today> I need some help!  (what?s new ? huh?)  While removing a retainer on my light canopy, the retainer shot into my aquarium.  While trying to dig it out, it got lost under the sand bed.  The retainer is spring steel and contains an amount of metal probably close to that of a penny.  Since the retainer is highly magnetic, I tried to fish it out of the sand (about 3 ?? deep sand bed) with a strong magnet ? with no success.  I have picked up every piece of live rock I thought it could be under but I am unable to locate the retainer. Do you have any additional suggestions for finding a piece of buried steel in a 180g aquarium with a 3 1/2 ? DSB and live rock? <I guess a conventional metal detector wouldn't work under water, huh?> Worst case ? at least this is not copper; how dangerous would it be if this small piece of steel is left in the aquarium?   <Well, It's obviously not a perfect situation, but I suppose that the impact of this piece of metal may be minimal, given the water volume, especially seeing that it is so small. On the other hand, if it makes you feel better, you should run aggressive chemical filtration with activated carbon/PolyFilter, or other "metal removing" media, in the hopes that any potentially toxic leaching could be minimized> Currently this is a FOWLR aquarium but I am getting ready to add corals and begin keeping a reef. Your advice is greatly appreciated!--Greg <Well, short of mounting another dredging expedition, I suppose that you are just as well served to use the aforementioned chemical filtration media full-time. Good luck Regards, Scott F.> Use of aluminium reflectors? HI Crew, <Hello Bob> On my Juwel tank, the fitted lights come with optional reflectors (which appear to be polished aluminium). <Yes... very nice units> As the lights are set very low in the hood, and directly above the water surface, I am concerned about the condensate getting back into the tank and giving a toxicity problem? <Me too> I called the supplier, and they told me that the reflectors would be "fine for marine use", but might "tarnish a bit from the salt" Hmmm? <He is steadfastly wrong here> I'd like to improve the lighting efficiency, but I'd rather add more light than do anything silly.......it's just that they are soooooo easy to fit, and they are also not too expensive.... Any comments? <I would NOT use aluminum/aluminium in or around marine systems> regards Bob (UK)  UK.. hence the "aluminium" for you US folks, I know you call it  Aluminum   :--) <A metal by any other colour. Bob Fenner in the colonies>

- Eclipse III Hood Problems - I am ready to move on from my Eclipse 3 system. <Seems a familiar theme today.> Right now it's sitting on top of a Sea Clear 30"L x 12.5w x 24H 40 Gallon acrylic rounded corner freshwater aquarium. I have the heater set for 78 degrees, and my two 24 inch lamps are on for about 8-10 hours a day. The reason I want to scrap the hood is despite what Sea Clear said about a perfect match, water condensation keeps dripping down the sides of the hood and then continues down the side of my tank. If there is an solution you can suggest... whether it be a modification to the existing hood or purchasing a new hood/filtration. <No suggestions that I can think of... probably not a marriage made in heaven, this hood and tank.> I have been looking at the Eheim Ecco/Pro canister filters, but if you have any suggestions I would really be grateful. <The Ecco canister filters are very nice - well designed.> Thanks! -- S <Cheers, J -- >

- Eclipsing the Eclipse - Hi all, my wife and I both love your site and try to keep up regularly. We have had moderate success these last 2 years keeping a 29 gallon saltwater setup.  It is in one of those eclipse systems by Marineland.  You are probably familiar, they have all the lighting and filtration in the hood.  A terrific concept but we are beginning to suspect not well designed for saltwater. <Yes, you are correct... you win... a brand new Eclipse system... what? You don't want it? They are a good enter into the aquarium hobby, but not made for upgrading.> We are able to only keep very hardy fish such as damsels and clowns and a few others.  We've tried a flame angel twice without success.  Anyways, we are positive it's gotta be water quality with the lack of protein skimmers etc. <Quantity and quality - the two are joined.> One other VERY disappointing result is our sand.  It started off great the first 6 months, very white, like the nicest beaches in the Caymans.  We both loved the sand.  However, over time, it was taken over by red slime.  We tried the yellow powder (can't remember for the life of me the name) and it helped somewhat, but in the end, it's a real mess to clean up by hand.  Again, I'm sure bad water quality. <Among other things...> So, we think we are ready to move up to a bigger system.  We have the room, the time, the money, and the desire and are considering tanks in the 125 gallon and higher range. <Ahh wonderful.> My questions are these: 1.) We are considering placing all the filtration equipment in the basement, about 10 feet below the tank.  Is this wise? <It will be quiet in the room where the tank is - that much you can depend on. Do take steps in the basement to deal with moisture, water spills, etc. Other than that, many folks wish they had the luxury of this option.> Can we do our water removal and additions from our basement as to not have to stand in front of a tall tank with buckets and hoses all the time? <One of many benefits.> Obviously, siphoning would still be done. <Sure, no worries.> 2.) Given our bad luck with sand, can we steer clear of any bottom material all-together. <If you want, but I think with some research and planning in advance, you can avoid these problems in future systems.> I have noticed this at my LFS who keeps a very nice 300 gallon setup in this manner.  Nothing in the bottom, just lots of fish and rocks. <Many folks do... think the fish seeing their reflection in the bottom glass is a bit problematic for the fish's mental health... best to at least paint the underside of the bottom panel if you choose this route.> 3.) At my LFS, the few display tanks with sand appear to have at least red algae in the sand, not to the degree we had, we had slime.  Is it that difficult to prevent even under the best of conditions? <Not difficult to prevent if you understand the origins/causes - read here: http://www.wetwebmedia.com/bluegralgae.htm > 4.) Without bashing any particular aquarium manufacturer, are my experiences with the eclipse system common among those who try to keep saltwater in them? <I think so - again, tank was designed to bring folks into the hobby, not be an end-all-be-all system for everyman. Most who use these realize at some point that they won't be building the reef of their dreams in an Eclipse system.> Thanks again for services. <Cheers, J -- >

Glass covers Hello. I just have a quick question on removing the glass covers over my reef tank.  I have a 75 gallon reef with mostly soft coral (colt, xenia, Shrooms, zoo's, etc). I have a retrofit 4X65 watt power compact lighting setup in my canopy. About 5-6 inches above water.  Should I remove the glass covers? I am worried about splashing and dog hair (yellow lab)?  Any worries or suggestions?  Mike <Hi Mike.  I am assuming you mean the glass covers on the tank, not on the lighting fixtures.  No worries with the dog hair.  I also doubt splashing will be an issue if you are careful.  If you will sleep better at night, you can fashion makeshift covers for the lamp sockets to protect them.  Best Regards.  Adam>

DIY Hood Questions Hi Guys, Just built a 6' hanging style hood for my 125 gal.. Has 3 metal halides and 2 VHO's. Was wondering if a piece of 1/4" laminated safety glass is a sufficient UV safe splash shield. My glass man told me this would filter 99% of Uv rays, thus saving my eyes etc. from these harmful rays. Also have an ice cap fan with built in thermostat on one end, and planned on having an open grill on the opposite end. Should the fan blow  fresh outside air across the lights, or  pull (exhaust) the hot air out.?                     <Awesome! Building your own hood is a great way to save money- congrats.  This glass sounds appropriate.   As for the fan, it should pull fresh air in.  The side without the fan should act as the exhaust.  Good luck! Ryan>    Thank You in Advance, Louie

Egg Crate- The Good And Bad Good day, <Hi there- Scott F. with you today!> Im changing my current lighting right now to metal halide and I would like to use an eggcrate top for heating/gas exchange and better lighting. I've been told that eggcrate can cast shadows and diffuse light and that eggcrate can be fairly opaque to point sources. Can someone please give me the complete explanation of the pros and cons of eggcrate with lighting? Thanks! Travis <Well, Travis, here are a few. Some of the "pros" are that you can use eggcrate to help newer corals acclimate to your system's lighting, and create shade effects for corals that prefer different types of light levels. Some of the "cons" are that this material will unduly shade the corals that reside beneath it, in some cases. Also, the eggcrate can become brittle and crack, or even melt over time. There are many, many other pros and cons to the use of egg crate; of course I only touched on just a few that came to mind...In the end, you might be well-served by chatting about this topic with a few fellow hobbyists...You'll probably hear many different opinions and ideas on the topic as you talk to different people. In the end, you'll probably have to pick up some egg crate (it's cheap, fortunately!) and experiment. If it doesn't suit your needs, you can always try something else with it- like build a plenum! Good luck! Regards, Scott F>

Lighting Canopy Questions... Hello, <Hi there! Scott F. with you today!> I have a 90 gallon tank with a base and a canopy top. I want to buy PC lights 4 X 96 watts for my tank. Is this too much or too light for fish, live rock, mushrooms, invert, and maybe soft corals, anemones??? <Nope! Sounds just right to me!> Also I went to my local glass shop the other day to see if they could make my a cover for my lights I want to get. SO basically The cover I discussed with them is going to be made out of Lexan. The light will be placed in this cover, basically it is a rectangular box with an acrylic hinge top. SO the light will be mounted in this Lexan box and the Lexan cover/box will be mounted on the canopy it self. Is this a bad idea?? <Only if it prevents heat from escaping, and filters out too much of the light...> I did not want a glass canopy in the inside of my wooden canopy top. So the water and light will have the Lexan cover between them. Every time I open the top of the canopy I will see the light fixture in a Lexan box that is mounted on the canopy cover. I talked to them about putting some fans into the design and say they could do it. Should I have two fans on one side exhausting heat?? Or should I make the Lexan cover longer and put two fans on one side sucking air in and two fans on the other side exhausting air???? <That would be cool (no pun intended), if you could have two fans blowing in, and two blowing out...> By the way the tank is 48 X 18 X 24 inches. The light fixture will be 36 inches long. Please tell me what you think. Will the Lexan cover discolor, melt from the four pc lights that will be only about 1-2 away from it. <Not sure...I'd consult the glass place...Tell them about your intentions, and verify if this material can stand up to the potential heat...> The reason for the mounted on cover on the canopies top itself is that there is a little trap door in the front of the canopy's heavy (mahogany canopy and base, solid mahogany)) for feeding the fish. If I put a glass canopy on the top of the tank  I would have to open the canopy's top or trap door and still have to open the glass canopy to feed the fish/. <Clever!> Please reply as soon as possible. Zeyad Yusuf <Well, Zeyad, I think that your idea is fine...just make sure that the hood ventilates properly...>   P.S  Thank you and I love your site!!! <And we love to be here for our fellow hobbyists! Good luck! Regards, Scott F>

- Finding a Glass Canopy - Dear Sirs, I have been looking for a glass canopy for my 26.5 inch long fish tank.  This is proving to be quite a difficult task.  Do you have any information that could help me?  I am getting desperate, and annoyed with my odd shaped tank. <Hmm... do you need an entire canopy or just a glass top - if just the top, I'd head to a glass shop and get them to cut be a couple of pieces of tempered glass. You should be able to find the plastic bits [hinge, handles, and back cover] without difficulty although you'll probably need to cut them to length.> Thank you. Joseph <Cheers, J -- >

Canopy Paint - 9/24/03 Can you suggest a paint for the inside of a light hood over an open reef tank?   <tub&tile or swimming pool 2-part epoxies work very well and dry hard/non-toxic. Else, any baby safe latex paint that you coat with polyurethane will be fine if above water> I have some bathroom paint lying around and was hoping to use it. The problem is it contains a mildewcide. <alas no... it is very toxic to aquatic life because of the anti-fouling agents as you have suspected> I was hoping to use it if  I sealed it with a few clear coats of polyurethane. <not worth the risk> Is this even all that critical, since most of the surface area of the hood will be covered with reflectors for the new T-5 lights? <agreed... but still not worth the risk.> Get that next book going, I am out of good reading material. <writing it as we speak <G>.> Thanks as always, Ken <thank you, my friend... Anthony>

-Mounting fans in canopy- Dear Crew I just received my MH/PC retrofit. I also bought 2 Ice Cap fans.  My question is this: What is the best way to place them?  One at each end of the fixture? Across from each other?  What? <One on each of the long ends, one blowing in, one blowing out. Good luck with your new lights, and enjoy the new found heat! -Kevin> Marion

Tank cover - filtering MH? 7/30/03 Hello Anthony! <cheers> My today's question is concerning cover for my tank. My tank is completely opened from top and I have a 250W MH lamp hung 30 cm above the water surface. Today my two sons were playing in the living room and a small ball was dropped into the tank, which leads me to the question: If I place a cover, simple glass or acrylic, leaving empty spaces on left and right side to allow aeration, would it be a problem? <it may affect (sometimes for the better... sometimes for the worse) the coloration of some corals by filtering the light and UV through glass. More importantly however... the lack of a concealing or enclosed canopy (as evidenced by the ball finding its way in freely) gives me great cause for concern regarding the naked MH light being seen by you or your family. Human eyes should not be allowed to look at the MH lamp unprotected... do conceal this better my friend as with a hooded canopy> Would it cut on my lights penetration or have some negative influence on aeration?? <the light yes perhaps... but the aeration is little issue of concern. You can inject enough aeration otherwise with good water flow and protein skimming> I would prefer acrylic cover, because it is light and it is does not break easily. However my concern is that acrylic absorbs some lighting. Your input would be much appreciated. <the acrylic is not without problems of its own (warping and discoloring quickly in time). Perhaps a piece of tempered safety glass would be better. Seek as clear and thin (say 6mm or less)> Thanassis, leaving for 10-day holidays. <safe travel and return my friend! Anthony>

Avoiding Reef Jerky Dear WWM Crew, <Scott F. at the keyboard tonight!> I am finally ready to stock my 437 gallon (80"x36"x36") Acrylic Tank with two Hawaiian Dragon Moray Eels, in a reef type environment.  The tank has two openings each measuring 16"x22". My concern is weather to leave these openings uncovered in order to enhance air exchange or cover them with acrylic panels to make the tank "eel proof", as well as control evaporation.  Lighting initially will be a 6 foot custom Sealife ABS Fixture with four 96W P.C.'s.  The tank is plumbed to a 150 gallon open sump and connected to a large Aqua Medic Protein Skimmer.  I would appreciate your advise on whether or not to cover the tank openings. Thanks, Ron Well, Ron, as you have surmised, Morays can slither out and around just about any form of confinement, if they feel frisky. I've even seen them many times, when I was fishing, slither right out of the water to eat fish that we were cleaning on the rocks - an amazing sight to see! I'd opt for a cover of some sort- either the factory supplied acrylic slot covers, or a finer eggcrate over the openings. Either way, you do want to secure them, or they can definitely become "reef jerky"! Regards, Scott F>

Light Hood and Tank Access I'm reading The Conscientious Marine Aquarist -- very good information. <Yes, an asset to anyone in the hobby> My question is a practical one.  I have a 55 gallon tank (48X13X20).  I have a Hamilton oak light hood (halide/CF) which is 50X12X7.5.  It covers most of the top of the tank.  I cannot hang the hood from above.  I can't scoot the hood back because of the hoses/cords hanging over the back lip of the tank.  Can you think of a workaround so that I can access the tank daily for feeding, etc.  without having to lift the hood and setting it on the floor?  I also use glass canopies, half of which folds up to access the tank.  I can't move the hood enough to fold up the canopy.  Is there a way to make a miniature, say 4X4, opening or door in the front right of the glass canopy or use a plastic canopy and make a little door?  That way I could perhaps move the hood enough to get access to a little opening. <Yes, this is why customized and DIY hoods are popular. If your glass top is similar to others I have seen, it has a plastic strip that acts as a hinge between the two pieces of glass right? You should be able to remove the smaller piece (normally the front) by sliding it out of the hinge. Any glass shop should be able to cut the glass to give you what you want. Or, you could replace the smaller piece of glass with plastic eggcrate to give access to the tank. Eggcrate is used as a diffusion panel in overhead lighting. It is sold by home/hardware stores in 2ft x 4ft panels. Hope this gives you some ideas, Don> Lifting it off weekly is not a problem, but lifting it off daily or twice a day is tedious and increases the risk of breakage. Am I the only one that has problems with a hood that covers the entire top of the tank?  I've never read this question anywhere. <Certainly not the only one. I have seen some very clever uses of drawer slides and hinges used for the tops of chests that solve the problem. Most of these designs are on DIY sites so you would have to be pretty handy with woodworking tools to accomplish some of these.> Thanks, Randy

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

Plexi-mirrors Hi Crew! I'm planning to put 2 175W metal halides above my 80 gal reef tank. Future inhabitants: T. maximas, fish, corals (I don't know which ones yet) and some invertebrates. Enough light? I am planning to supplement with 2 110W actinic VHOs in the future, also (far future... no rush=no funds). Well here is my real question: I've been reading up on your canopy FAQs and Bob has suggested using acrylic coated Mylar or plexi mirror as a DIY reflector. I am concerned that my metal halides will melt this material. Won't they? <Maybe> Will stand-offs for mounting the halides away from the mirror help? <Should. Do see the manufacturer of your light fixture's recommendations for how far they need to be away from acrylic> I love your site. It's full of a wealth of information and a friendly & helpful community of reefers. Thanks all! Iona <Thank you for writing. Bob Fenner>

Custom Lighting? I have a glass 48 inch flatback hex tank. I've used it for freshwater fishes and would like to now create a reef system. The canopy has a sleeve for a single tube lighting fixture to sit in. It simply isn't wide enough for anything larger, which I know I will need for the new system. Do you know of anyone that makes a more suitable canopy for this size tank? Or do you have an idea of how I could improvise? Thanks for your help. Russell <Well, Russell, I'm not sure of your tank's exact width, but you have a few options...Lots of manufacturers make canopies and retrofits for different sized systems. You also can consider the use of pendant systems...I'd do a little web searching for lighting systems and components. A good place to check out is hellolights.com, which offers a variety of lighting components, bulbs, etc., to meet a wide variety of tank configurations. Have fun researching and developing a system to meet the needs of your tank! Regards, Scott F>

Tank Cover and Lighting Hello WetWebMedia Crew, Your help and advice have been invaluable! <Thank you for the kind words!> I just wanted to get your opinion on my tank cover and lighting.  I have a 6' acrylic 125 gallon, with a total of 576 watts PC lighting above the tank in a canopy.  I have addressed the issue of moisture build-up in the canopy by 1) adding 2 CSL fans and 2) totally covering the 2 access holes on top of the tank with acrylic sheets.  Is there anything wrong with totally covering the tank on top?  Does the tank need some ventilation on top?  Will this be enough to prevent any electrical problems for the lighting (i.e. the lighting is not moisture-proofed)? (FYI, via a built-in overflow, the water flows down to a sump and protein skimmer below the tank). <The sump will help with gas exchange, so that should not be an issue. The totally covered top may be a problem if heat builds up. A small fan blowing across the sump will help cool the water. Normally, the canopy has an acrylic, or better yet, glass lens to help with moisture, splashes, and to contain heat in the canopy so it can be exhausted. You will have to monitor your setup to see how much heat becomes a problem.> Your comments are greatly appreciated, <No problem Ed, hope this helps, Don> Ed

Paint for canopy Hello, I hope you can help me, I am so confused about the type of paint to use on my "canopy" (it is more a light shield for my suspended MH fixture: a rectangular box with no top).  I fear that I have made a real mistake in painting it with acrylic/latex paint.  I was then going to put a clear polyurethane over that.  In your opinion, should I build another and just use a polyurethane stain.  (I wanted the canopy black on the outside).  For the sake of my reef tank inhabitants, I hope you can give me a definitive answer, as I don't want to make a mistake.  BTW, I used BC plywood.   Thanks C Pawley <Please see here: http://www.wetwebmedia.com/marine/setup/lighting/canopyfaqs.htm and here: http://www.wetwebmedia.com/tkstdfaq.htm and the next FAQs file beyond re. Bob Fenner>

Paint for Canopy Hello, Hope you are well today! <Yes, thank you> I was hoping you could answer a question for me: I have built a light shield for my suspended MH fixture.  (basically, a canopy without a cover)  I am going to paint it and would like your recommendations as far as sealants, primers and paints that would be non-toxic.  I used BC pine plywood and, this may be a dumb question, but, here goes:  I should prime it, paint it, then seal it, right?? <This is one approach to protecting the wood. You might also consider coating the exterior with polyurethane.> Thanks for your time and in advance for your response. Cheri Pawlak <You're welcome. Bob Fenner>

Re: lights crammed together!! Hi everyone, it's been some time since I've written,.......bet you missed me! <Welcome back Pam, Don with you today> Anyway, I have been plenty busy with my tank, continually trying to give it the best, which leads to my question/dilemma: I have a 75 gal reef tank. The problem is the cover. You see, I have the original cover that holds one large strip light. You know the type that opens in the front for feeding, then there's glass in the middle portion separated by a strip of plastic. This is where  I have crammed a second light into the small spot to supply adequate light. Still, I only have  300 watts total. What's out there for covers that will 1.) let you feed without taking a light off, and 2.) will allow enough room for lights??!! Do you understand me? <Yes> I would love to someday install an over the tank (suspended) metal halide model, but at this point the cost is too much for me. Any suggestions for a simple, clean design that works??? <Hmmm. I build custom covers for my tanks so the best I could suggest is to try the online sponsors listed on the WetWebMedia.com FAQ page here: http://www.wetwebmedia.com/daily_faqs.htm. BTW what are your plans for this tank? 300W on a 75 is not that bad. Don> Thank you all! Pam

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

Cost of a metal halide hood - 2/20/03 Hey <Hi. Paul back atcha'> I would like to know how much would a metal halide hood cost? <Depends on many things, the least of which is the size of your tank, what type of fixture, and brand.> Can you give me some web sites with cheap hoods? Thanks <There are a great many sites to find such. I would first think about what type of animals I plan to keep, what size tank I need to light, then I would look at the following links for information: http://www.wetwebmedia.com/marlgtganthony.htm http://www.wetwebmedia.com/marine/setup/lighting/mhmarfaqs.htm http://www.wetwebmedia.com/growingcorals.htm After this information has been assimilated, I would just click the various links that are advertised on this site and do a price comparison for the fixture you want. The links are on the right hand side and top of this page as well as here: http://www.wetwebmedia.com/WWMAdminSubWebIndex/general_links_pg.htmBe sure to look under Retailers/E-tailers. Hope this helps! Regards Paul>

Re: acrylic adhesives used in proximity to a stocked tank Great site! by far the best/ most informative fishy site I've ever encountered! Onto my question: I have a 180gal FOWLR tank stocked with a 80cm Fimbriated moray eel and a few disposable (obviously) damsels. The eel, "Corporal Clegg", has been my pet for about 8 years now and am looking to make an improvement, but am concerned about the Corporal's safety.  Currently weighting down the covers of the tank is just a 4ft piece of oak.  As you can imagine, the lighting of the tank can be greatly improve upon by securing the covers with a more translucent object.. this is my goal in life.  I was thinking it would be nice if I could glue some small "swing arm" type brackets made out of acrylic to the top of the tank as the solution (small and translucent == good).  Are there any adhesives on the market that you would deem "safe" to be used in such close proximity to the water and my fish?  I am sure that mounds of activated carbon and PolyFilters would be beneficial... >  I guess I should give you a little more info: tank is obviously acrylic with wet/dry, protein skimmer, and denitrification chambers underneath in the stand.  About 120lbs of LR, and 50lbs livesand. Thanks for your advice and suggestions. Mark <Hi Mark, The solvent in these glues is very volatile and will evaporate quickly, use a fan to exhaust the fumes from the room as they won't be good for you either. If this is done, no worries!  Craig>

Re: canopy and light design I think I'm nearly complete on the canopy and light design and, if you be good enough to make comments on the plan and open items, I'm done. 200 gallon 72L x 24 W x 27H.  I will have clams and SPS corals. I am having a custom built canopy and stand that will be against but not built into the wall (but will have a built-in look) set two inches away from the wall, so air can travel behind the tank.  So no "back" on the canopy other than the wall.  The front 1/3 of the canopy will fold up on piano hinges and fold back on itself.  The outside height of the canopy will be 14" high.  The canopy will be made out of maple plywood.  The inside of the canopy with be painted with white epoxy.  The fixture will be a Custom Sea Life retrofit kit 3 x 250 Ushio 10000K MH with VHO (actinics?).  The fixture is about 71" x 12.5" x 2" H. The fixture will be hung at least 1" from the underside of the roof of the canopy, so the bulbs will be about 10" from the top of the tank.  Perry at Champion insists that I need a lens cover, acrylic Plexiglas would be fine, hung 2" beneath the fixture.  It seems to me that this would interfere somewhat with access and may not be convenient to hang. Is it really necessary? He also believes fans are necessary and that it should be mounted on one end with a finger guard (is that a filter?) on the other end for optimal air flow.  He thinks that the canopy should have a back so that together with lens cover the "heated air" is enclosed and kept away from the water and then sucked out by the fan.  If I had to have a fan I would want it mounted in the top of the canopy?  Do I need one, and if so, where should it be placed? So I'm still uncertain over fan location and the lens cover.  Can you illuminate these issues? << Fan location: Yes you need fan(s). The idea is to keep the air moving to cool the canopy. There are some interest FAQs here http://www.wetwebmedia.com/marine/setup/lighting/canopyfaqs.htm and beyond about fan placement and if top/back/sides are best. The best placement is such that there are areas of stagnant air. Lens Cover: Excellent idea but acrylic too close to halide = melting!!!! Trap the air??? Never thought about that one. But keeping water spray out of the canopy is a good reason. May use coated glass to cut down on UV. Oh, to my knowledge, a finger guard is a metal protector over the blades of a fan for exactly that reason, guarding your fingers. There may be a foam filter as well>> As always, your input is valued. <<Thanks, Don>> Lawrence M. Benjamin

RO or RO/DI another quick question if you would.  On my 90 gal. could (should) I keep the glass top off.  I do have a maxima clam at the top of my rock work under the dual 175 MH's and a lot of salt builds up on the glass top quite quickly. <I would leave it off, try to reduce splash, spray otherwise. Please see here re this issue: http://www.wetwebmedia.com/marine/setup/lighting/canopyfaqs.htm Oh, and the areas on tridacnid clams. Keep reading, dreaming, learning, sharing. Bob Fenner>

Electrical safety in aquaria Thank you very much for your input, Anthony.  Trust me when I say it's valued greatly.  I think I'll keep a close on it (for condensation and salt), and buy my own cheaply made plastic cover if necessary, or better yet, a high quality one. <agreed, my friend> One more follow-up question if you don't mind.  What, in your opinion is the worst that can happen if condensation or salt builds up.  I know that an electrical arc will be created eventually, but am I just in danger of blowing a bulb, or is there a possible fire hazard here? Thanks again, and a happy New Year to you! Eric Newman <there are bigger issues here than product application and durability. Regardless of how safe or unsafe any such devices are... every aquarium should have the aquariums electrical life support equipment plugged into two separate lines (for safety in case of non- whole-house outages (single devices fails or breaker trips otherwise). You don't want all of your eggs in one basket, so to speak. The two biggest draws for any system are pumps vs. lights. Those two system are your separate lines. Those lines should be shock protected with ground fault interrupters (GFI). Nowadays, you can even buy an extension cord with a GFI built right into it! If you run your aquarium equipment off these two GFI protected lines, you will have little or nothing to worry about with any reasonable electrical application. Best regards! Anthony>

Light covers and marketing Hi, First I'd like to praise your site as having an unbelievable amount of information on it!  It's wonderful to see, and has given me endless reading material. <very glad to hear it> I plan to buy a 75G Oceanic Reef Ready, with Standard Oceanic Canopy, and would like to purchase a Hamilton 4X96 retrofit kit, compact lighting system.  I have read that Mr. Fenner (and some others) advocate removing any glass covers and using egg crate if anything, instead.   <agreed for most> Having experience with optics from a former career, I don't doubt that there is a lot of truth that this practice can be beneficial to maintaining light intensity and spectral purity, so I like to idea and want to try it. Here the question: When I called Hamilton to get some specifics, they insist that this lighting system will require a plastic (I'm assuming plastic) cover, or shield for the light, if no glass top is used over the tank.   <my first experience with Hamilton was about a decade ago. I ordered a light system and wanted to opt out of the plastic lens. They said they didn't recommend it and could not guarantee the fixture if I did. I asked if I could just use a piece of Plexiglas on the custom canopy I was building instead... They restated that they did not recommend or guarantee it. So I bought their overpriced  "special" lens to keep my guarantee and guess what arrived at my door? A rough cut piece of Plexiglas (chips all along the edge) with the Plexiglas paper still attached. I trust that they have improved their tactics since then... but the memory lingers. For what its worth :) > My question is...is this necessary to prevent damage due to condensation as they say, <there is definitely some truth to this if your hood is not properly ventilated (and it should be)> <and if so, won't using their shield defeat the purpose of removing the glass cover?   <correct> Is there any truth to the theory that condensation build-up on the lights will cause problems, or are they just trying to sell me a $4 piece of plastic for $40.00?   <I feel that I got misled as you have suspected> The kit itself is fairly cheap, $399.00. Above all else, I don't want to take the chance of burning my house down! ; Any advice you can give me would be greatly appreciated. Thank you, Eric <since you are not building your own hood, but buying commercial... I would hope that they have designed the fixture with adequate ventilation. There is as much or greater of a concern for splashing and salt creep on the bulbs if you neglect a weekly wipe down. The condensation is easily prevented (muffin fan). Best regards, Anthony>

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

Egg Crate Material Reference Lighting Hi Steven, Just a comment about using egg crate material to cover the tank instead of glass covers. I read somewhere a few years back, that an enterprising student studied the effect of egg crate material on light and discovered by turning the egg crate upside down (opposite of the way they use it in elevators and office buildings) it increased the fluorescent light intensity by almost 30%. Don't know if its true, but I thought I would share. Paul E. Proue of St. Joe Beach, FL <It is definitely true. Egg crate has distinct top and bottom sides. If you look closely you will notice that there is a slight taper to the plastic. Used one way it blocks out light, the other way it focuses the available light. -Steven Pro>

Lighting Hi again, Currently, I've got 2 x 96 watts power compacts about 2-3" off a glass cover and cool it with a fan, but I don't think the glass cover is such a great idea because it blocks the light, accumulates a lot of salt, and also the canopy gets pretty hot after a few hours. What height would I have to place these lights off the surface of the water to not have the lights so they are still effective, but not ruined by the salt spray? <I would leave at 2-3 inches off of the water surface and instead attack the source of the salt spray. Remove any venturi airlines on powerheads, lower any spray bars, remove any airstones, use a bubble trap on your protein skimmer, etc.> Are there better solutions than glass covers? <Some people use egg crate material to stop fish from jumping out while allowing nearly full light.> I'd like to grow LPS corals, mushrooms and polyps. Thanks, Ben <You are welcome. -Steven Pro>

Reflector question Hi Arthur> OK, for the 75 gallon tall reef tank, I think I've finally decided to try swapping my 2 250W 10K MH for 2 250W 20K Radiums. It's not a drop in wattage, but I wanted to at least try it before tossing the ballasts and having to get new 175W ballasts, and I can get a pair of Radiums for around $160. Can I maybe drop the wattage going into the tank by removing the reflectors?  <The Radiums sound cool Not quite the same as 400watt Radiums, but should be nice! No, you won't lower the wattage of anything, that's the amount of power the lights use (250 watts), not the amount of light they emit. Removing the reflector WILL reduce the amount of reflected light, but it won't do anything about wattage, and MAY be a fire hazard without it.>  I have Spider reflectors, and removing them should help in lowering the overall wattage entering the tank, no? I'm a little concerned about warping the wood of the canopy without reflectors - would you remove them or find some way of dampening them, maybe with heat-resistant paint for example? <No. Leave the reflectors and raise the hood or lights or use shading of some kind if you are worried about temporary added light levels. The Radiums should be about the same intensity but a different spectrum than the 10K's. Leave the reflectors, they reflect a LOT of heat from the wood hood and paint is painted onto....wood, that's still flammable!>  Thanks for all of the help the last couple of days...you provide an invaluable, extremely helpful resource for the reef tank owner to be able to ask questions that aren't covered by a FAQ... Arthur <Hope this helps you Arthur, Craig>

Re: tank tops, Lighting Up His Life... Hey fellow fish-keepers: <Hey! Scott F. Here> If I may, a follow-up to my homemade top questions: I only wish to use some form of fluorescent for my 55gal, up to VHO, if necessary. In this case, can I use Plexiglas? <Acrylic/Plexiglas should work okay> I lean this way so I can do it myself. How much will it cut down my light? The thinner the better?  <How much/how thick really depends on the type/grade of acrylic you will use. I'd recommend talking to your local hardware store about the different grades of acrylic and how much light (or what spectra) they'll block out> I read so many opinions an watts per gallon. Can you give me (or point me to) a reliable rule of thumb (or range-of-thumb) for FOWLR, then moving up to hearty inverts, and MAYBE (way in the future), the easier corals (if there are any)?  <Really, no hard-and-fast rule for FOWLR-although if you are interested in deep-water species, you probably won't want as much light/intensity. If your intent is to eventually move up towards keeping corals, and you like fluorescents, I'd go with the VHO in a configuration that lets you put several bulbs in the hood, preferably of higher wattage. this way you have flexibility for the future. Oh- and pick up a copy of Anthony Calfo's excellent "Book of Coral Propagation" for excellent ideas on coral husbandry, lighting, etc.> I do not want anything that you can't sneeze at the tank without them dying, and I am very flexible with fish choices. <That's good, because you can plan your population with an eye towards the future, avoiding outright coral-munchers, like large angelfish or triggers, and maybe look at reef-compatible fish that are both attractive and hearty. Then, you can add a few hardy soft corals down the line> Also, can I use a single bulb in multi-bulb fixtures until I need the extra light to cover for the future? <Probably, yes-but do consult the manufacturer of your light fixture, as there are considerations, such as electrical safety and wear and tear on the bulbs> Thanks, Rich

Tank Tops Hey Guys, Super Job (wise cracks and all): <Gotta have a laugh now and then, right? Scott F. with you this afternoon> Thanks for all of your help through this last month of my new journey. I have an All-Glass 55gal. The top is sectioned in half and has the double cover, single bulb combination. First, are they all like that? Could I have gotten a different maker of the same size without this partition/support thing in the middle? <There are many different configurations on the market, the one you have is fairly common> I want to replace the standard 40 watt 48" light with something more. I have seen doubles, but are there triples? <Once again, you can purchase hoods/fixtures in many different configurations> A triple would give me 120W, just what I would need, right (3watts per gal)?<Depends upon what you're trying to keep; for example, Tridacna clams require intensity that standard fluorescents generally cannot provide. For a fish only tank, or freshwater plants, this may be adequate. Again-largely depends on your animals/plants. Hard to generalize.> I think I have seen a quadruple, but that would cover the whole top? <In all likelihood, yes, but depends upon manufacturer's specifications> Can I get two 24" tops so I can leave one side on while I do stuff on the other? <Certainly a possibility-but remember, if your tank is exactly 48 inches wide, there may be some "overhang" on each side from the hoods. Have you considered one of the hanging pendant lighting systems? They are usually available in compact fluorescent and metal halide configurations, and may give you the access and flexibility that you want. Why don't you check out some of our advertisers' web sites for information on the various options available?> I also want to make my own cover(s); should I use Plexiglas or real glass or something else? And what thickness would be right?<This depends upon the type of light you are using. Lights that burn at high temperatures, such as HQI could damage Plexiglas/acrylic over time. Additionally, some of these lighting systems give off considerable UV radiation, and glass may be more appropriate to shield the inhabitants. Salt creep is another consideration. Much to think about here. Best to consult the tank/lighting system manufacturer and find out what they recommend.> When I cut slots for the HO filter space, heater and whatever else I need, how tight should they be? A couple of millimeters space or like none? Should I drill holes for air in the top? <Open tops favor gas exchange, but there are (once again) lots of considerations, such as fish that jump, evaporation, etc. If you are cutting holes for filters, etc, you can allow a little extra space for gas exchange. Not necessary to be air tight-but do think of the aforementioned considerations.> Sorry, I didn't mean to ramble...thanks! Rich <And thank YOU for stopping by!>

Painting custom canopy <<Hi Jason and Karalyn>> I've searched your site and read up on canopy painting recommendations. Based on this information I'm planning on painting inside and out with a black latex based paint (to match the stand) and then coating with a Varathane product. Will this finish be safe over a reef setup? <<Yes, should be fine.>> Also, the retro kit reflector will cover the inside top, but not the sides. Will this make a difference or should I go with white paint inside, or look for more reflector? Thanks for any input. <<Either way will work. White latex or reflector will help reflect more light. Some of the manufacturers make a deep reflector which might extend down the sides more (PFO).>>  Jason & Karalyn Jacobs <<Cheers! Craig>>

Re: Advice Please Lighting (canopy reflectorizing) Sounds good but surely mirrors have more reflective properties than any other material and if I seal the mirrors well on the inside of my tank it shouldn't cause harm ??? Just asking you are the guru please advise . <Mmm, will have to look for a while in analog files... folks have tested these materials for reflectance properties... and the "mirrored closet" material (Mylar encased) comes out near tops... and is relatively cheap, easy to work with... Glass mirror and silvering can rust, chip... Bob Fenner> Werner Schoeman

Re: Advice Please Lighting Hi Anthony thanks I have read the link , quick question apparently mirrors aren't the best bet but due to rather big financial constraints what about using normal aluminium foil in my canopy ?? <Pardon my intervention. Bob F here. I am a big fan of the Mylar and acrylic (inexpensive and good reflection properties) that you can buy through plastic fabricators, large hardware stores... and cut to size, install with silicone sealant.> Werner Schoeman

Set-up (substrate and Louvre/louver, tomato/tomatoe, potato/poetahtoe) The Louvre was mentioned on your website http://www.wetwebmedia.com/reef2.htm in the FAQ section under the subtitle "Is Plexiglas OK in saltwater? It is also referred to as egg crate - was wondering whether it should be level with the sand, above the sand or have a space between it and the sand for the critters to clean under and for me to blow the detritus out from under. <I would prefer to have it such that there was a small gap between the egg-crate and the sand so that water would be able to move behind the rocks and also for small cleaning critters to travel under.> By the way - I have been to the Paris "Louvre" - neat place - didn't have enough time though to see it all. Thanks <Have a nice day. -Steven Pro>

Re: Set-up (canopy, cover matters) The Louvre was mentioned on your website http://www.wetwebmedia.com/reef2.htm in the FAQ section under the subtitle "Is Plexiglas OK in saltwater? <Yes... most often termed "louver" or egg-crate here... Guess this threw Jason.C> It is also referred to as egg crate - was wondering whether it should be level with the sand, above the sand or have a space between it and the sand for the critters to clean under and for me to blow the detritus out from under. By the way - I have been to the Paris "Louvre" - neat place - didn't have enough time though to see it all. - Thanks <I see, understand. Note there are two types of this product that appear identical. Do seek out the polystyrene product if you can. Much sturdier. Bob Fenner>

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

180/175 Canopy Greetings Bob, et al. Thanks for your continued great work on the site and wonderful advice. It is amazing how much I have absorbed over the last month! Is there anyone who builds custom canopies for glass aquariums? Or that could take a manufactured canopy and install lighting and add proper ventilation? <I would contact Custom Sealife and Oceanic. I know Oceanic does build some custom stuff. Otherwise, look into local kitchen cabinet manufacturers/woodshops. There are various DIY sites with plans on the internet, so that you could have something for them to work from.> I'm looking for someone who could put together a quality canopy with MH/VHO lights for the attached aquariums and sizes. I'm not very DIY inclined because of time constraints. Thanks, Marc of Greenville, SC 180 Reef Ready? 72? x 24? x 24? 175 Bowfront Reef Ready? 72? x 24 x 28? <Good luck! -Steven Pro>

Jumping Fish, Tank Cover, Reflector Hello there, I decided to remove the eggcrate grill covering my 55g tank's top. I noticed that the PC lighting made a cool looking shimmering effect. I also noticed that the white eggcrate reflected a lot of the light away from the water. <Eggcrates have a top and bottom. Take a close look and you will notice that the sides of each square have a bevel to them. You want to orient it so that the bevel works to focus your light.> Should I keep the eggcrate on? <I like them.> I'd like to leave it off, unless that shimmering effect is unhealthy for the fish and anemones <No, just fine for the animals.> (3 FL Condys, and a bubble tip...I'll be getting rid of the Condys in time). I have a yellow tang, Kole tang, cinnamon clown, 4 damsels (4striped, 3 striped, and two yellow tails). Are any of these known jumpers? <Anyone can jump.> I currently have 2x55w PCs (two more on the way) hanging off the inside top of my oak canopy...I drilled the clips that hold the bulb into the canopy and snapped the bulbs into place, then took some metal-like yarn and tied the ends of each clip together....just in case the bulbs slipped out of the clips, the wire would catch it...I don't know if this will actually work, but it gives me peace of mind since they are now just hanging over open water (3.5 to 4 inches over the water...hard to get an accurate measurement). I am saving up for reflectors, but right now I have aluminum foil reflecting the light back to tank. Is this OK/safe to do for the meantime? <Sure, have seen it done many times.> I came across a FAQ in the archive and Bob mentioned to someone something about using Mylar or Mylar sheets or wardrobe mirrors or something like that for "something", but that "something" was never stated in the question (it was a reply). Was Bob suggesting using this reflective material as a light reflector? <Yes> Could I use pieces of cut mirror as reflectors? <Yes, but rather heavy.> Oh, I realized the other day that my 55g tank is not really a 55g tank. If I use the dimensions/measurements of the outside of the tank, and divide by 231, I get 55 gallons. But when I measure the inside of the tank, it actually comes out to about 40 something gallons. Do tank manufacturers label their products based on inside the tank measurements or outside the tank measurements? <Outside measurements.> And last, do I use the manufacturer's "55g" label when considering lighting needs (e.g., 4 watts per gallon for 55g tank equals 220watts) or my own calculations of actual in tank capacity? <The manufacturer's labeling.> Very last, does this make a difference in calculating for live rock stocking? <No, everyone uses the manufacturer's labeling for convention.> Thank you again, Randy M. Yniguez, MA <You are welcome. -Steven Pro>

Hood Here's an odd one for you.. One of the aquariums I have is a 20 gal.. It is very old (grandma gave it to us when I was 11 and she had used it for years before I'm 25 now) and apparently it was either bought somewhere other than the U.S. (My grandmother lived overseas) or is just so old that it doesn't match the measurements of a regular 20 gal tank.. I have gotten a new hood for it as the old was two pieces of glass and a light, but it doesn't fit well at all and allows for a lot of water splashing out of the tank.. Does anyone know where I could get a hood w/ the exact metric measurements of 30 cm deep by 59 cm long.. The fact that the metric measurements are so perfect is what led me to believe the aquarium was not made here.. Any help would be appreciated! <indeed...do browse UK search engines using appropriate keyword searches. Ultimately, though... you can get a plastic hinge, handle and splash guard from Perfecto MFG and others to fit 1/4 inch plate glass that you have cut to fit (relatively inexpensive at the local window/auto glass dealer). Then snap the pieces into place and put a simple strip light on top. Not quite as attractive as a proper hood... but much less expensive by far. Best regards, Anthony>

Best/Better Reflectors for reef light canopies Sorry, I was out of town for last few days. <Sanjay... no worries. Thank you my friend for taking the time to share your opinion> Of the pre-made reflectors, the 2 most popular are the spider light and the PFO reflectors. If you have problems with getting them into a hood, the next best option is to make your own by buying sheets of the reflective material and installing them in your hood. Champion (Lighting and Supply Company) sells different sizes and there may be others on the web who do as well. White paint is not a good solution, neither is the flashing from Home Depot. The reflective material should be anodized to prevent corrosion. Using these reflective materials (most of them are the Everbrite by Alcoa) you can easily get 20-40% more light into your tank. Sanjay. <wonderful... I'll be sure to pass this along. Thanks again very kindly, Anthony Calfo> Lighting and Reflectors Anthony- Thank you so much for the email from Sanjay! I feel quite honored to have both of your input into my lighting system. :)  <it is my honour that anyone should care to know my opinion> I just ordered my 2x175 watt MH PFO dual, & 110 watt VHO actinic IcaCap430. The MH are Ushio 10K and the Actinic lights are 03 URI (or IUR, RUI, IRU.. damn my dyslexic mind!) <correct...URI, outstanding quality fluorescents> I ordered the spider reflectors. My original question was not if the Spider reflector was my best choice, but if I can use the Spider Reflector with the VHO bulbs below it.  <I do recall... my apologies... I did not have enough experience to comment and Sanjay may have overlooked it> No worries, in 5-7 working days I will find out if it can work. In any event I know now what will be my best second choice if it does fail to work. <please do let us learn from your experience> Thanks for your time and effort! It has made difference for the positive for my future coral. Robert <you made the difference for caring... continue to do so. Anthony>

Question for you :) (marine lighting) My wife has been in contact with you via e-mail a number of times with some questions on setting up our new 125 gallon aquarium (reef) <Anthony Calfo in your service> I have one for you myself: When building a lighting cover, would it be wise to use a mirror as the reflector, I did it in my 66 gallon reef and never had any problems from it that I know of, mind you it may be the cause of many problems that I am unaware of. Let me know your thoughts on this. <yes... beyond safety issues, mirrors are made by spraying a nasty aluminum based solution onto the back of the pane... it WILL degrade under the humidity of your environment. They are many better DIY reflectors out there. Mylar is popular, polished aluminum, etc. Surf the net some more with a keyword search for "DIY light reflectors" Thanks Scott Allen <kindly, Anthony>

MH 175 and enclosed canopy Bob, I have not asked anything of you as yet. Now, I may be getting into trouble. I have built a killer lower canopy for my 125 all glass (about 16 in. high), with large doors that keep *all* light from escaping and easy access to the reef. This thing will also slide forward, so that I can service the overflows, etc. <Sounds very nice> The canopy is in two parts and of abs plastic. The top ( or lighting part) is a work in progress. I have a limit switch to cut off the 175 MH lights at 160 degrees that I can place at the hottest (or any) part of the upper canopy and a 130 make/ 90 break snap disc control for the two 4 in. RS, 115v fans.  <Have your later input re the lower limit (110) for the high shut off> Lighting will be, two 175 MH, four 4 ft (40 watt) and two, 3 ft. tubes. By the way, those (White-Rodgers) snap disc controls are great and available from Grangers <Grainger> for only 7 to 8 bucks each and I have tested them for several hours, but not on the canopy !. The limit switch will take care of up to 10 amps and I chose the (3L02-161) with a manual restart instead of an auto restart. I figure that if it cuts the hot lights off, there is a good reason and the problem needs to be corrected prior to switching back on. <Yes> My thinking on this project is to keep it light weight so that I can remove it without help and I hope to be able to use a lightweight acrylic shield between the two canopies as I wish to avoid heating up my tank. This same thinking is the reason, I do not wish any motor in my sump or in the tank. I am running two Quiet ones and driving the skimmer and the 5 nozzle water movers that are in the lower part of the tank and behind and between the live rock off of one pump. The upper supply (six directional nozzles) are on the other pump. The two fans are both blowing in and can be partially directed at the acrylic sheet, below the MH lights <An acrylic sheet below the lights? I would not use one here... and want to mention/ask that you have heat and light deflectors as part of the fixturing above, separating the MH lamps from the ABS sheet plastic making up the canopy?> This should not cause much pressure, because I will have some holes in the top, covered by a four foot by one foot, black plastic roof heat dissipater from Home Depot, on top of the light canopy. <On top... but also something inside... deflecting the heat from the structural hood> My question (before I get further with the upper part of the canopy), is... How close to those 175 watt, 10k MH lights, can I place the acrylic lens? <Were these supplied as part of the fixture? As UV filters? To protect against touching, splashing? If so they should be mounted per the fixture. If not provided as a component, I would mount the lamps at least a foot from the waters surface, sans any in-between material> Do you know at what point the would start to deform, melt or bend etc.? <Depends on some properties of the specific make-up, thickness... likely not too far from just being near the lamps... in the mid to upper 100 degrees F. Do take care here, contact the dealer you bought these units from. Am cc'ing Dave Adkins here. Dave? Bob Fenner> Thanks, Dave Moose

Re: MH 175 and enclosed canopy Thanks Bob and hi Dave, ABS and Metal Halide in the long run is scary enough. Are you using 1/4" or thicker? What size tank is this? I guess I'm reading that you have an entire closed hood? The only air moment is the two fans? If you contact someone on the ABS/manufacture to discuss thickness vs. melt down you can come to some conclusion on what to expect. The general rule on Metal Halide temperature is the old rule of thumb which states for every watt is an element of heat. Hope any of this helps. David Adkins <Thank you David... oh same fellow as Aquariumlighting.com for you all>

Re: MH 175 and enclosed canopy Thanks for the reply, Bob. (and Dave) One thing is very apparent to me now. I did a sorry job of depicting for you, just what it was that I built for this 125 gal tank. No one sold it to me, so, I can't put any fault on anyone but me. The top canopy (the part with the lights, fans and thermostats and limit switch with the smaller electronic ballasts on top of it) is only 10 inches high and sits on the 3/16 in. acrylic sheet, which is inserted into the top of the bottom (larger) canopy. The MH ballast of course will be separate from the sump area and the canopy. This was sealed in such a way, that the water (or air) from the lower, or main canopy, cannot get to the light canopy except (perhaps) via the fans on each end. But even then air and water would have to travel 13 inches around a corner and up about 20 inches more. I know that you have been saying that nothing should be between the lights and the water, but I have found , prior to building this thing, that fans on water a lot of heat is a sure fire ticket to massive and constant water additions  <And waste heat reduction> and if not watched constantly, the relative salt content of the remaining water, will increase too much. Not to mention the effect of up to 600 watts of light on the temp of the reef. The acrylic (if it works) will stop all (or most) of that. <But... the acrylic will reflect an appreciable amount of light... and alter spectral penetration...> This acrylic is more optically clear than glass. <Than some types of glass> I do have (in addition to the mirror finish aluminum above the MH lights) some "Bobcat White" painted aluminum 1/16 in. ionized sheets between the retro mirror finish aluminum and the ABS and stood off from the ABS with 1/2 in inch nuts, as a heat sink and shield, with the holes for escaping hot air at the sides and in places that any lights can still reflect downward. <Ah, sounds like a good design> I have just finished testing a half hour ago, with only the two MH (on the back deck ) and the fans did not even come on. Of course it is a little chilly out there. I am beginning to think that it is going to be relatively safe (as far as any heat is concerned) to go ahead and place the other lights in there tomorrow. My concern now is twofold. One, the phase/color shifting your talk about and, the other concern is what happens to the thin but well supported acrylic when about 600 watts of light hits it, even if the fans and the attic heat dissipater is working fine. <Only way to really tell is to try it out... you might want to mount a thermometer on the acrylic sheet for a test run... while you're still present... and see if the sheet approaches the flash point> I could of course had one blowing in and the other out. But, I tested that two days ago, using some military fog and noticed that there is only a funnel of air going in and out and not enough turbulence in corners and particularly on the acrylic shield. I think that I like the effect of the fans blowing in and forming a pressure that escapes from the top. An air condition engineer friend told me that I should have both fans blowing in from the top at each end and then dispelled from the roof ridge thingy and that would cause the most turbulence and coverage. <Interesting> But, I didn't like the thing bringing in air that had just been dispelled. As usual, I tend to "over engineer" and trying my best to idiot proof this (good looking) monster. Thanks much for any input or even telling me that I a dead wrong. I am continuing to study the problems involved in having something between the lights and water. To be safe (I think) I can keep this light canopy to a safe temp. These two 4 inch fans move a lot of air in a sealed container that is letting air out only at the top. I think the ABS stays structurally sound to 200 and the acrylic to 160 or more. I think I can stay well below this. <Not so sure re the acrylic here> I say that I think !. In any case, I will test the whole thing over the next few days (weather permitting), on the driveway behind the house. . I can add more fans (if needed). I could of course just remove the acrylic and have the lights about 20 some inches from the water. <I would take off the acrylic for sure. Who can say as it gets older, dirtier, the ambient temperature gets warmer, if it may ignite.> By the way, I have also built a 12 by 2 stand and reservoir that the tank cabinet is sealed to, and sits on. Just as an additional protection against the 30 gal sump or pumps malfunctioning. This helps also, in that you do not have to bend over to watch the tank critters and rock. This tank is only 4 months old and the live rock is doing cured and a ton of discovered critters and new ones every day are being found in the rock. I am just getting ready and looking forward to adding some light loving coral etc. Thanks for any all help, I am learning and you guys have been where I am traversing. Dave Moose (in North Carolina) <Be chatting. Bob F>

Re: MH 175 and enclosed canopy The acrylic (if it works) will stop all (or most) of that. But... the acrylic will reflect an appreciable amount of light... and alter spectral penetration...v Not only that but in time you will have yellowing, most acrylic will bow with moisture and because "things happen" will apply you/animals will start putting small little fine scratches that will now trap salt creep and or algae. It sounds like you did a lot of research and thought into you lighting set up. Please keep me/us informed as time goes on. Who knows you may have designed a hood that will with stand time and thus we will be able to pass on your findings. David Adkins <Ditto! (Always wanted to write that, and need to send self a copy for posting for browsers). Be seeing you David. Bob F>

MH 175 and enclosed canopy (part 2) Mr. Fenner, I made a error in my first mail to you. I said that the fans were on a thermostat that was "130 make/ 90 break". The thermostat is, in fact, 110 and 90. Sorry ! <No worries> I didn't know how to post to your site, so I just sent the e-mails. You may post them on your site if you wish. Or not, if you care not too. I do love reading your answers to other's problems. Thanks so much, for being so much help to all the folks. <And you for your help, input. Bob Fenner>

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