DSparks Posted March 20, 2004 Author Share Posted March 20, 2004 I spent $4.00 for my glass and clips at a local shop. Great deal IMO. Bananagoby, I'll post some dimensions later today, after I get my juices flowing. It's still a little early Link to comment
DSparks Posted March 23, 2004 Author Share Posted March 23, 2004 UPDATE: I'm going to buy some more glass today to cover the two ends of the MH enclosure. There is way too much un-filtered UV light getting into the tank. It's taking out a Xenia. I'll probably go ahead and add in another 13W PC as well. I'll post a pic once complete. Link to comment
jmt Posted March 23, 2004 Share Posted March 23, 2004 So that's what's melting your Xenia. Link to comment
DSparks Posted March 23, 2004 Author Share Posted March 23, 2004 I'm hoping it's that simple . . . Link to comment
onthefly Posted March 23, 2004 Share Posted March 23, 2004 It sucks it's something you can't see.....I had UV entering the tank from the uncovered rear portion (HOB return) and it was bouncing off the back glass panel and frying the backsides of my acro frags. Throw glass down on as much as you can....... Link to comment
Undertheradar Posted March 23, 2004 Share Posted March 23, 2004 von, the "temp" in tempered is talking about the high temps that are used to make it stronger than regular glass...not the heat resistance it may or may not have after. Then again...maybe the 'pyr', aka 'pyro' in pyrex means the same thing according to that logic...lol. But the real reason I posted is to mention the UV filtering capabilities of regular glass. Not alot, to sum it up. You might want to consider getting actual UV glass...or ripping it out of an existing halogen work light. Think about it. Halogens put out less UV than a halide...any day...yet they use special UV glass in every one. Now, halides of the DE sort put out waaaay more...wouldnt you want to use at least the same if not better protection than a halogen?...esp when the bulb first fires?...thats when it's UV output really spikes...after that, they dont put out as much. Regular glass does filter out 'some' UV, but not much. And thickness is a determining factor as well. 1/4" will filter out much more than 1/8". In windows for houses, they use LoE film to filter out UV on top of what the glass does...and even this combination only filters out something like 50% of the UV from the sun...makes you consider the overall UV filtering properties of glass, doesnt it? Now, glass alone might be able to filter out UV, but more than 1/8" might be in order. More like 1/4" or 3/8" for better protection. The good news is that once you reach a certain thickness to block UV, you will block all of it...Just like ozone in the sky. And D, rather than trying to put more glass all around the bulb to prevent 'leaks' why not just use a deeper reflector (or bend the current one)...bringing the sides of the metal down some to keep the light shining down rather than waste it going every direction? Just my .02 Link to comment
onthefly Posted March 23, 2004 Share Posted March 23, 2004 UTR - this has been debated to death in about 12 threads....... Link to comment
DSparks Posted March 24, 2004 Author Share Posted March 24, 2004 onthefly, do you know of a definitive source on the whole tempered vs. non-tempered glass debate? Link to comment
Von digity Posted March 24, 2004 Share Posted March 24, 2004 Oh woops, thanks for pointing that out UTR. Here I was, thinking I'm all smart and stuff... Now I feel like a dum dum. I shoulda known that too... I'm gunna ask my physics teacher about the U.V. filtering capabilities of glass. From what my college textbook says, "glass filters out all U.V., blah blah blah." But nothing specific about what type of glass. All they use is as an example is a drawing of a window in a made-up house with U.V. lights being reflected off of it. Link to comment
Von digity Posted March 24, 2004 Share Posted March 24, 2004 Alright, I take back my thoughts about tempered glass. UTR is right, I didn't even need to ask my physics teacher. A simple google search gave me all the convincing I need. "Different types of glass do tend to let through varying amounts of the lower energy UV-A light (as it is right on the edge of the visible spectrum), but this is believed to be less damaging. However, when purchasing sunglasses, it is wise to look for a UV protection factor as it is believed that even UV-A can damage the sensitive cells in your eyes."- http://physics.about.com/cs/light/a/010803.htm and "What percentage of UV light is blocked out by glass? Normal glass (as used in windows) is transparent to UV radiation up to a wavelength of about 330nm (or UV-A light). The transparency is quite high so almost all UV-A light will pass through glass. Beyond 330nm (UV-B and UV-C) almost 100% is stopped."- http://www.sciencenet.org.uk/database/phys...ic/p01347d.html Link to comment
onthefly Posted March 24, 2004 Share Posted March 24, 2004 Sorry for the long post, just want to try to be thorough..... The tempered vs untempered debate has nothing to do with the UV absorbing/scattering properties of the glass. So let me address that first. Tempering is a process they do to glass, once it has reached it's final shape. Example, you go to the glass shop and say you want this 9x16 rectangle with 4-6 different cuts put in it. They cut it, then temper it.....I know this because I just went thru this about 6 months ago. This process makes the glass about 4x stronger. The thermal "strain point" for soda lime glass (what HD sells) is 914F. As stated in a previous thread, I used a meat thermometer directly under my MH (about 2") and it read 120F.....That's a hot day in Phoenix! Most houses in Phoenix don't use tempered glass on the windows. Now for the UV absorbace. Von has graciously proved what I've said several times before (and what I was told by the retired physicist). I NEVER said that soda lime glass blocked 100% UV! What I said was that it blocks the "harmful" shortwave UV B and C. If you guys think that the tissues of corals that grow in the tropics (in 5-10 ft of water, where the surface can actually focus light even stronger) are equivalent to retinal cells, then please stop reading my post, go out and get some LoE UV glass, and please ALWAYS were your sunglasses! UV-A does not carry the same energy as UV B and C, it's almost in the visable spectrum. It will yellow the shiznit out of a couch or artwork, it will even give you a sunburn with "prolonged" exposure, but it doesn't pack the same punch. To reference Eric Borneman, SPS and the corresponding zooxanthellae, not only produce the pretty pigment we like to see for nutrient production, but also UV protection. Maybe a little UV-A is a good thing, after all, they put Vit. D in our milk so people who live in crappy climates don't get rickets (caused by a lack of Vit D, which is produced in your skin as a result of sun/UV-A exposure). Obviously, some of us have had some physics. Cool, I hate being one of the only science geeks here! But again I want to ask the masses, do people actually think that the "UV filter" (which is twice as thin as my glass top) that comes on the $9 regent fixture or my $19 halogen desk lamp is anything special.....its just glass! I don't even think it is tempered.....Do you think that SE MH bulbs have some magical coating that can survive the VERY HOT temp so close to the light source.......it's just glass! Soda lime glass is 6 parts washing soda, 2 parts lime stone, and 7 parts silica. That's why glass is such a good filter, because of all the "crap" in it. HQI bulbs (high quartz iodide) are incased, not just in quartz, but HIGH quartz......which will not absorb UV until about 214nm....but then your toast! I DO NOT....want anyone to do anything they don't trust themselves to do. I researched this here, at RC, online, at the glass store, and at HD. I COOKED my corals (like a dumb arse) when I switched over because I ran an acrylic top (remember, plastic doesn't absorb unless it is coated...something I didn't know). I then ran a glass top, except for the back 1.5" (because of my heater and HOB overflow). Like I stated, the UV entered my tank, bounced (actually refracted is the word people who've had optics and magnetism will related to) off the back wall and fried, very specifically, the back half off of 3 of my acros. Everything else in the tank that was sheltered from the "bounce" by LR, but was directly under the MH was fine. The front tissue on the fired acros was fine, the backsides have exposed skeleton now. Once I covered the entire top with 1/8 regular old glass....everything has done fantastic. Don't believe me...thank god! I don't want anyone to lose sleep thinking..."OTF gave be a bunch of BS info". Go to RC, look up what people are using to UV filter their GIGANTOR tanks with 4x 250W DE MH bulbs.....HD glass! Sorry for the long post guys. Link to comment
Undertheradar Posted March 24, 2004 Share Posted March 24, 2004 D, have you considered mounting the halide in one of those halogen fixture retrofits? I did, then for extra actinic, I made a hood with 36watt actinics in the front and back...and left the middle open cuz I cut a 9"x6" hole in it that the halide shines through. This gives the hood similar venting to that of a pendant, yet allows you to use actinics...(one 10 gallon has a 70watt + 2x36wattPCs and another just uses a 15,000K TUNZE bulb). Link to comment
KrackerG Posted March 24, 2004 Share Posted March 24, 2004 The glass that comes in those regent fixtures (some of them) have imprinted on the glass itself, “ UV FILTER GLASS ” so for you to say that it just regular glass in incorrect. And all glass in NOT the same, jmt…others. Honestly tho, I believe reg float glass is fine… better than nothing…. Link to comment
DSparks Posted March 24, 2004 Author Share Posted March 24, 2004 Nice post OTF. UTR, last night I finished enclosing the MH fixture with more glass. There shouldn't be any UV entering the tank now. I'll post more pics later this evening. I also added another 13W PC and moved the Aromat ballast to the back of the hood (thanks Von!). So now I have 70W's of MH and 26W's of PC. Not the best I've seen over a 10, but certainly enough to keep everything that I'm interested. Again, look for pics this evening. Link to comment
Undertheradar Posted March 24, 2004 Share Posted March 24, 2004 you should see how it looks with 2x36wattPCs actinic...really really cool. It makes the tank look like daylight...except all the blues and colorful things have a really crisp glow... Link to comment
DSparks Posted March 24, 2004 Author Share Posted March 24, 2004 Yes, I love how the GSP glows under this setup. Although I've only seen the tips since they haven't come out yet They also glow under the moonlight. Link to comment
onthefly Posted March 24, 2004 Share Posted March 24, 2004 I've emailed Regent this morning......if they get back to me, I'll post whatever they say! Again, Some of the fixtures at my HD had "UV filter" on them, others did not......That was another deciding factor into my decision. Maybe they put UV filter on there for liability reasons with all these idiot nano reefers gutting them for parts .....Labelling, kinda like the natural "artesian" spring water, bottled in Newark, NJ. I'll post the reply, if it ever comes! Link to comment
KrackerG Posted March 25, 2004 Share Posted March 25, 2004 i saw a guy using a regent fixture on his jobsite...he was a carpenter framing/drywalling...anyways, he was using the same fixture that we use without any glass! he said it broke and now its easier to change the bulbs. he says he uses it all day.:/ Link to comment
DSparks Posted March 25, 2004 Author Share Posted March 25, 2004 Hopefully ONF will get a response from Regent and put a lot of this UV debate to rest. I still owe some pics. I'll try again this evening. Link to comment
KrackerG Posted March 25, 2004 Share Posted March 25, 2004 what is he verifing from regent...that the glass IS uv filtered glass!!?? thats already been done. reefriot quote : "i called the manufacture of the pendant and the glass in them is tempered and UV so that problem is solved." page 1, first post on thread, DIY 70watt or 150w MH HQI pendant i believe ALL regent type fixtures are UV filtered glass regardless if it's printed there or not... Link to comment
onthefly Posted March 25, 2004 Share Posted March 25, 2004 I think this will clear things up: What I asked was: 1) is the glass in the regent fixtures "really" UV filtering glass (i.e. LoE)? or 2) is Regent using regular old glass (I didn't mention SL glass) and printing "UV filtering glass: Do Not Remove" for liability reasons? And here is the response I got this morning: "Mr. Jones, You are correct. Regent brand halogen floodlights come with tempered soda lime glass lenses as standard. Soda lime glass is sufficient to block most harmful UV radiation." Christopher Burns Senior Customer Relations Representative Consumer Markets Division Peachtree City, GA cburns@cooperlighting.com So, Kracker.....it is tempered, but IT IS JUST GLASS....not LoE UV filtering glass....JUST GLASS!!!! So like I suspected, they print it on the lens for liability reasons. Again, if it concerns you.......please don't take my, or any other persons, word at face value.........find out for yourself! Have a nice day Link to comment
onthefly Posted March 25, 2004 Share Posted March 25, 2004 Sparks - I owe you some pics too! Link to comment
KrackerG Posted March 25, 2004 Share Posted March 25, 2004 liability reasons? so you think they are writing UV Filter glass on there just to cover their aszes?? and what could they be liable for...someone getting skin cancer and sueing them. but wait...we wrote UV Filter on the glass so we are not liable...?? hmmmmm, I think you want to think all glass is the same...and btw, not all fixtures have UV Filter glass printed on the lens...and I have seen about 5 different brands and 10 diff models making a great day:) Link to comment
KrackerG Posted March 25, 2004 Share Posted March 25, 2004 Originally posted by onthefly ..Maybe they put UV filter on there for liability reasons with all these idiot nano reefers gutting them for parts .....Labelling, kinda like the natural "artesian" spring water, bottled in Newark, NJ... do you think they know we are gutting them? do you think we impact their sales enough for them to write UV GLASS? do you think they care? i doubt it.... Link to comment
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