question re :tank lighting

[redbelly1]

Anyone in this forum work at big als on innes??? if so can you tell me what type of lighting you guys had on one of your tanks were it made the tank look dark but the rocks and stuff on the bottom glow?

[BigDaddy]

That would be black light.. you can buy a bulb at any home depot...

[DARKPHREAK]

http://aquariacanada.com/osCommerce/product_info.php?cPath=1_74_89_96&products_id=853

[redbelly1]

i dont think it was black light because i was told that would kill the fish. was told that by someone that work at big als.

[DARKPHREAK]

They are called Super Actinic. Very blue.

[squeeker]

I don't see how blacklight could kill fish...

[redbelly1]

Thnx im gonna check it out !

[darkdep]

Fluorescent bulbs work by generating massive amounts of Ultraviolet light, which reacts with the phosphors on the inside of the tube to generate visible light.  However, Blacklights use different phosphors and generally emit certain wavelengths of UV.

From the Fluorescent FAQ:
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Blacklight Fluorescent Lamps

BL in the tube designation (e.g., F40T12BL) means "blacklight", which is a fluorescent lamp with a phosphor that emits the longest largely invisible UV wavelengths that are both efficiently and fairly cheaply possible. This phosphor seems to emit a band of UV mainly from 350 to 370 nanometers, in the UV-A range.

BLB means "blacklight-blue", which differs from "blacklight" only in that the glass tube of this lamp is darkly tinted with something with a dark violet-blue color to absorb most visible light. Most UV gets through this, along with much of the dimly visible deep-violet 404.7 nanometer line of mercury. Most of the violetish-blue 435.8 nanometer line is absorbed, but enough of this wavelength gets through to largely dominate the color of the visible light from this lamp. Longer visible light wavelengths do not significantly penetrate the BLB's very deep violet-blue glass, which is known as 'Wood's glass'. The UV is the same as that of the BL lamp, being mostly between 350 and 370 nanometers.

There is a 350BL blacklight lamp, using a different phosphor that emits a band of slightly shorter UV wavelengths in the UV-A range. The reasoning for this lamp is that it is supposedly optimized for attracting insects. These lamps are one variety of UV lamps used in electric bug killers.

There are other UV fluorescent lamps. There are at least two different UV/deep violet emitting fluorescent lamps used mainly in the graphic arts industry, emitting mainly wavelengths between 360 and 420 nanometers. Possibly one of these is also used in bug killers. I have noticed one kind of UV fluorescent lamp for bug killers with a broadish band phosphor with significant output from the 360 nanometer range (maybe also shorter) into visible wavelengths around 410 to 420 nanometers or so.

There is an even shorter UV-A lamp used for suntanning purposes. I would guess the phosphor emits mainly within the 315 to 345 nanometer range. One brand of such lamps is "Uvalux".

There is even a UV-B emitting fluorescent lamp. Its phosphor emits mostly at UV-B wavelengths (286 to 315 nanometers). It is used mainly for special medicinal purposes. Exposing skin to UV-B causes erythema, which is to some extent a burn reaction of the skin to a slightly destructive irritant. Use of UV-B largely limits this to outer layers of the skin (perhaps mainly the epidermis) and to parts of the body where skin is thinner. UV-A wavelengths just over 315 nanometers can also cause sunburn, but they are more penetrating and can affect the dermis. Please note that the deadliest varieties of skin cancer usually originate in the epidermis and are usually most easily caused by UV-B rays.

There are clear UV-emitting lamps made of a special glass that lets through the main shortwave UV (UV-C) mercury radiation at 253.7 nanometers. These lamps are marketed as germicidal lamps, and ones in standard fluorescent lamp sizes have part numbers that start with G instead of F. These lamps will work in standard fluorescent lamp fixtures.

Cold-cathode germicidal lamps are also in use; these somewhat resemble "neon" tubing.

Be warned that the shortwave UV emitted by germicidal lamps is intended to be dangerous to living cells and is hazardous, especially to the conjunctiva of eyes. Signs of injury by the UV are often delayed, often first becoming apparent several minutes after exposure and peaking out a half hour to several hours afterwards.

Please note that non-fluorescent (high pressure mercury vapor discharge) sunlamps generally emit more UV-B rays rather than the tanning-range UV-A rays. These lamps do have substantial UV-A output, but mainly at a small cluster of wavelengths around 365 nanometers. Tanning is most effectively accomplished by wavelengths in the 315-345 nanometer range. In addition, no UV suntanning is completely safe.
---

Got all that?  There isn't really a black and white answer here; I would suggest that a standard blacklight will not harm fish.  That being said, as cool as it may look in a store, I'm not putting one over my fish.

[mseguin]

The tank I assume u are talking about has moonlights over it. A few of the corals and anemones glow under the moonlights.

[redbelly1]

thnx guys for the info!!!!!

[babblefish1960]

Darkdep, interesting array of nm details. I feel I must protest, I do not have the facts on hand, but I do recall someone killing all of his fish with blacklights to have the tank look cool for his soiree. What exactly killed them was never determined, it could simply have overloaded the water column in dead macro and micro organisms. The point was however, after the party, all of the fish were dead.

UV is destructive,(as you say,we use it in sterilizers and bug zappers), and to put one over a tank is ill-advised.

This is my opinion only, but one in which, without facts, I feel confident enough to say, don't do it.

[darkdep]

I would agree.  You know how old fluorescent fixtures often turn yellow and brittle?  That's because of leaked UV.  Even REGULAR Fluorescent tubes don't block it all.  

It's no wonder people who work under them all day report health problems.