Utah Reefs Homepage
  New Posts New Posts RSS Feed - Another reason to run UV protectant glass
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Another reason to run UV protectant glass

 Post Reply Post Reply Page  12>
Author
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Topic: Another reason to run UV protectant glass
    Posted: October 11 2005 at 1:06am

A good friend of mine with one of the most incredible acro tanks I have ever seen had an unfortunate event happen the other day.

He is running single ended, mogul based 250w lamps. For whatever reason (splash, bad bulb, etc) the outer glass on the bulb broke off, but the inner bulb remained in tact and still firing (just like a double ended bulb with no shielding).

The side of the tank that was exposed was completely (in his own words) melted by the time he got home from work. All coral colonies were dead. There was a completely obvious line between live and dead coral - all corresponding to the light spread of the un-protected bulb.

So... who wants to run double ended without a UV shield??? 



Edited by ssilcox
Back to Top
Aquarium Creations View Drop Down
Pet Store
Pet Store
Avatar

Joined: August 20 2003
Location: DRAPER
Status: Offline
Points: 3234
Post Options Post Options   Thanks (0) Thanks(0)   Quote Aquarium Creations Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 8:24am
I do belive a HQI or double ended bulb has outer glass sleeve, I have had that same thing happen awhile back with a 400Watt bulb with no ill affects, pretty strange,
Aquarium Maintenance,Consulting,Custom Built Glass Aquariums
Rimless/Euro,24Hr Emergency Service 8015485201
Www.UtahAquariumDoctors.com
[email protected]

Back to Top
bdfitch View Drop Down
Guest
Guest
Avatar

Joined: December 23 2003
Location: United States
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote bdfitch Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 9:54am

I have been running my 250W DE bulb without a shield from the get-go.  Am I to expect a coral meltdown?  Looking at the lamp last night, the light is produced inside a smaller bulb which is surrounded by the outer glass (quartz?). 

I looked at the spectral plots that were reported by Sanjay Joshi... there isnt that much UV that these lamps produce, at least down to 300 nm.  Is there information of the spectral properties below 300 nm?  Presumably the shield is to just protect from the UV, but depending on the wavelength, the water will absorb quite a bit along with the organic matter that is in the water.  I should run an adsorption/transmission spectrum of my tank water in the UV-visible region to see what it looks like...
--
Brian
20g Nano
Chicago
Back to Top
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 10:09am

Originally posted by bdfitch bdfitch wrote:


I have been running my 250W DE bulb without a shield from the get-go.  Am I to expect a coral meltdown?  Looking at the lamp last night, the light is produced inside a smaller bulb which is surrounded by the outer glass (quartz?). 

You are right - there is a outer shield - and it is quartz. (Which provides no UV protection whatsoever).

I have heard a lot of stories from people that have run DE's without a shield. I am wondering if the coral acclimates to the increased UV exposure. So when a coral acclimated to normal, shielded UV is suddenly exposed to larger than normal UV - they die.

I know I have seen a write up on the UV numbers for DE bulbs. I'll see if I can find it and post it.

Side note - there is enough harmful UV coming off of the DE bulbs that would make me not want to put my arm under it or my kids next to it.

 

Back to Top
bugzme View Drop Down
Guest
Guest
Avatar

Joined: May 22 2004
Location: West Jordan
Status: Offline
Points: 4815
Post Options Post Options   Thanks (0) Thanks(0)   Quote bugzme Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 10:22am
I didn't know that. Where can I buy this glass?
Jeff
125 tank
50 gallon sump
T-5 lighting
Rum drinker, Carbon User
I KNOW ROCKS THAT ARE YOUNGER THEN ME!! I AM A Realist! I write what I think!!
Back to Top
Mike Savage View Drop Down
Guest
Guest
Avatar

Joined: July 15 2005
Location: Murray
Status: Offline
Points: 19173
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mike Savage Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 10:46am
Jeff, if I remember right from my reading, all you need is "tempered" glass.


Back to Top
bdfitch View Drop Down
Guest
Guest
Avatar

Joined: December 23 2003
Location: United States
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote bdfitch Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 10:55am
Originally posted by ssilcox ssilcox wrote:

You are right - there is a outer shield - and it is quartz. (Which provides no UV protection whatsoever).



That is not entirely true... i agree that quartz will transmit significant UV, but it begins absorbing at 300 nm.  There are also many grades of quartz including UV absorbing and UV transmitting.  Just looking at GE quartz website, there is a grade of quartz that will block anything less than 300 nm... which is as good as using glass "UV shields".   I assume lamp makers do not use such high grades of quartz mostly due to price. 

I do think that the animals can adjust and maybe that is why nothing has melted when i went from PC to the MH.
--
Brian
20g Nano
Chicago
Back to Top
Adam Blundell View Drop Down
Presidency
Presidency
Avatar

Joined: June 24 2002
Location: Davis County
Status: Offline
Points: 18526
Post Options Post Options   Thanks (0) Thanks(0)   Quote Adam Blundell Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 10:56am

I had a bunch of frags fry on me recently.  I thought it may have been (despite my advise) actually caused from too much light.  However, my halides have been unshielded for the past month and that may have been the cause. 
They are shielded now, like they used to be, but I'm still not sure that hqi bulbs are really giving off harmful uv

Adam

Come to a meeting, they’re fun!
Back to Top
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 11:18am

Eric Borneman has written that corals can adapt to moderate levels of UV-B, but UV-C can be quite detrimental to tank inhabitants.

Quote from Fenner:

UV A: 320-400 nm, UV B: 280-320 nm, UV C : 200-280 nm

Some UV "A" range is useful, necessary for some light-using life; "B" and "C" are dangerous/harmful. UV "C" is absorbed by the planet's celebrated ozone layer; within it's band, 257 nm is the energy produced by UV sterilizers. UV "B" can be halted by glass and water, is very destructive to nucleic acids (life) and photosynthetic activity. UV "A" is effectively filtered out for the most part by special filters and bulb coatings provided by manufacturers. I only will install and address the use of metal halides with the use of UV filters, even though they may coated/engineered to be used without them. This added protection against radiation poisoning may require more shielding action and periodic cleaning, but is well worth the "cost" in preventing you and your livestock from "burning". Also of concern is the explosive effect of these 'high-pressure' light sources getting splashed, broken by splashing water, or cumulative bubble-mist.

"Korallrevs akvariet" by Fosså & Nilsen, vol 1. On page 46 there is a table that references OSRAM databook and it clearly shows that HQI lamps produce all types of UV radiation (A-C).

HQI 250W (at 1000 lumens):
UV-C 29 mW/m2
UV-B 108 mW/m2
UV-A 900 mW/m2

Glass shields (Tempered or not - tempering just allows for the glass to stand up the high temperatures produced by the lamps)

1/4" Clear glass

Wavelength Transmission

300 nm 0.0%

305 nm 0.0%

310 nm 0.1%

315 nm 0.7%

320 nm 3.5%

325 nm 10.7%

330 nm 22.8%

335 nm 37.5%

340 nm 51.5%

345 nm 63.2%

350 nm 71.8%

355 nm 77.8%

360 nm 81.7%

365 nm 83.8%

370 nm 84.4%

375 nm 83.0%

380 nm 82.4%

385 nm 84.2%

390 nm 86.2%

395 nm 87.2%

400 nm 87.7%



Edited by ssilcox
Back to Top
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 11:22am
Back to Top
Adam Blundell View Drop Down
Presidency
Presidency
Avatar

Joined: June 24 2002
Location: Davis County
Status: Offline
Points: 18526
Post Options Post Options   Thanks (0) Thanks(0)   Quote Adam Blundell Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 11:51am

Shane you need to find a new hobby to take up some of your time

Adam

Come to a meeting, they’re fun!
Back to Top
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 11:57am

What I need to do is get back to work

Back to Top
jfinch View Drop Down
Guest
Guest
Avatar

Joined: March 06 2003
Location: Pleasant Grove
Status: Offline
Points: 7067
Post Options Post Options   Thanks (0) Thanks(0)   Quote jfinch Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 2:36pm

You are right - there is a outer shield - and it is quartz.

Is that right?  Do you know why it's quartz?  The outer sleeve on SE bulbs is a borosilica glass (which does adsorb most UV).

Back to Top
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 2:41pm

Dunno why - but I can tell you for sure that most all HQI/DE bulbs have quartz sleeves. (There are some DE bulbs coming out now from Ushio that have a UV shielding in their sleeve)

HQI - High Quartz Iodide



Edited by ssilcox
Back to Top
jfinch View Drop Down
Guest
Guest
Avatar

Joined: March 06 2003
Location: Pleasant Grove
Status: Offline
Points: 7067
Post Options Post Options   Thanks (0) Thanks(0)   Quote jfinch Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 3:04pm

Thanks Shane.

FWIW, acrylic/polycarbonate is even better then glass at attenuating UV emissions.

Back to Top
Seaul8r View Drop Down
Guest
Guest
Avatar

Joined: April 15 2005
Location: United States
Status: Offline
Points: 190
Post Options Post Options   Thanks (0) Thanks(0)   Quote Seaul8r Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 3:53pm
Shane, it looks like your not the only one that should get back to work     .
75 Gallon Display, 75 Sump/Refug, Euroreef ES5-2 Skimmer, Iwaki 70 return pump, DIY Stand/Canopy
Back to Top
bugzme View Drop Down
Guest
Guest
Avatar

Joined: May 22 2004
Location: West Jordan
Status: Offline
Points: 4815
Post Options Post Options   Thanks (0) Thanks(0)   Quote bugzme Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 3:58pm
I put my arm under mine for about 2 mins and it got a little burnt. Iput a piece of glass under it now from a picture frame but how can you tell if it cutting out uv?
Jeff
125 tank
50 gallon sump
T-5 lighting
Rum drinker, Carbon User
I KNOW ROCKS THAT ARE YOUNGER THEN ME!! I AM A Realist! I write what I think!!
Back to Top
bdfitch View Drop Down
Guest
Guest
Avatar

Joined: December 23 2003
Location: United States
Status: Offline
Points: 168
Post Options Post Options   Thanks (0) Thanks(0)   Quote bdfitch Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 4:23pm

I thought the H in HQI referred to mercury.  The lamps are mercury (Hg, metal) quartz iodide (halide)... making mercury iodide the metal halide. 

 Anyone have an old lamp labelled HQI (could be a misnomer since not all DE bulbs are HQI) they want to dontae to science?  I am an analytical chemistry graduate student at the U and have many resources available to determine this stuff.  In particular an old XM 250W 20k would be ideal, since that is what I have at the moment.  Others would be accepted too...

Jeff... did you think that the burn could have come from the IR (heat) given off by the lamp.. put your hand in your hot oven and it will turn red too
--
Brian
20g Nano
Chicago
Back to Top
ssilcox View Drop Down
Guest
Guest
Avatar

Joined: November 17 2003
Location: Sandy
Status: Offline
Points: 3428
Post Options Post Options   Thanks (0) Thanks(0)   Quote ssilcox Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 4:43pm

Brian -

HQI - high/mercury - I think the US market scrooed that one up the same way that all double ended bulbs are HQI.



Edited by ssilcox
Back to Top
bugzme View Drop Down
Guest
Guest
Avatar

Joined: May 22 2004
Location: West Jordan
Status: Offline
Points: 4815
Post Options Post Options   Thanks (0) Thanks(0)   Quote bugzme Quote  Post ReplyReply Direct Link To This Post Posted: October 13 2005 at 5:01pm
No I had my arm way below the lamp.
Jeff
125 tank
50 gallon sump
T-5 lighting
Rum drinker, Carbon User
I KNOW ROCKS THAT ARE YOUNGER THEN ME!! I AM A Realist! I write what I think!!
Back to Top
 Post Reply Post Reply Page  12>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.406 seconds.