My question is directly related to the 250watt HQI bulbs, Im in the process of building my 220gal Reef tank (72"x24"x30") which will be mostly SPS, and some softies, and LPS in there too. I am gonna build my own lighting system which will house 3 maybe 4 of the 250 HQI bulbs, as I have read Sanjay Joshi's report and love the par and spectrum that they emit, However what concerns me is the UV rays that these lights emit. My tank will be in my Office about 2' away from where I sit for 10hrs a day 6 days a week, and I dont want to have Skin Cancer after 6 mos
I have talked with numerous glass shops and have read an indepth thread at ReefCentral about these DIY HQI lamps, As the glass shielding is what it all boils down to....What type of glass, and how thick should it be. There are a few things relative here from what I see....Heat, UV rays good to corals (SPS), UV rays bad to corals, and color spectrum. Most of the guys that have replied to this thread on ReefCentral seem to think that 1/4 tempered glass should be fine for shielding the UV rays enough to not cause damage, however talking to many glass experts in the past few days they have told me that regular 1/4" tempered glass does NOT shield that much of the U/V rays. I want the best of both worlds. I want to give my corals all that they need/want from these lights, and at the same time block out what can damage the corals and/or me. I have been told that their is 3 different types of UV A, B, and C. Which ones are good and which are bad? Or have I been misled? As far as glass goes its Measured In SHGC (Solar Heat Gain Coefficient) The higher the SHGC the more U/V will pass through it. There is also VT (Visual Transmittance) Which from the way the Glass experts explained it to me that the Higher the VT the Less par goes through the glass. This is all speculation on my behalf, I am by NO means a glass or light physics expert. My Glass man has told me that if I can tell him exactly which UV's I want to block and Which I dont want to block then he can probably supply the correct glass, now the other thing that he has told me is opaque tinting or filming layers in certain types of glass will block UV rays I.E.: a clear piece doesnt block much UV's, a slight opaque blue will block some UVs, and a slight blue green will block even more, and a green will block even more than the blue green etc etc. This particular glass he was discussing is called Low E glass and is made with a Pyrolitic coat as well as a Monolithic coat. My thoughts where that a shade of blue or even blue green may accomplish that "Perfect Coloring" effect and at the same time elliminating our harmful UV's ? here again this is all speculation....tell me what you think.
Here is the thread that most of this evolved around
http://www.reefcentral.com/vbulletin/showthread.php?threadid=32376
Warning: The thread is about 8 pages long
Any input you can give me would be greatly appreciated! If you feel up to it then you can just email me or just post your response right onto the thread.
Here is the thread that most of this evolved around
http://www.reefcentral.com/vbulletin/showthread.php?threadid=32376
Warning: The thread is about 8 pages long
Any input you can give me would be greatly appreciated! If you feel up to it then you can just email me or just post your response right onto the thread.
