Wierd Blue light

[bob`_your_dog]

Hey, i was just given a blue 4 foot light and ballast for R20 about $2.5 and i was wondering, all it has written on it is F40 T8 BLB 16, no name or model.
It's a very dull blue almost purple and isn't very bright at all, i was told it was for plants but i would like to use it as a night light? Are they usually very dim? or is it just old and lost it's strenght, cause compared to my other 40w's it looks like about 10watts

 

[bob`_your_dog]

Okay i have come to the conclusion that it is a black light. And it looks great at night!!! but I just read this Ultraviolet light, also referred to as black light, will kill your fish.

Is this true cause i have turned me light of for now, but i wanna put it back on!

 

[Lateral Line]

If it is a UV lamp, it will cause certain objects to fluoresce a-la disco dance floors. UV's would be no good for growing plants. What you may well have is a very old worn out Gro-Lux type lamp which have a pinky-purple colour and were always dim, and just got dimmer. Whatever, I would get rid of it and put a new full spectrum lamp on the starter.

 

[smithrc]

I'd go with an old wornout tube.
'black lights' are a deep purple in colour when turned off.

 

[bob`_your_dog]

well i'm not sure exatly what it is, but it causes everything to glow, my teeth look cool! When i get some cash i'll probably upgrade but for now i just wanna know if it's gonna blind the fish or sumding, i bought it from a closing down fish shop so i imagine it should be allright ???

anyway if it is a glow lux, would it be allright to just let it run all day with my day lights aswell even tho you cant see it at all when it's during the day, every bit helps i suppose?

 

[shrimpster97]

i want to make a black light aquarium, and get some neon tetras, that would look really cool!

 

[Lateral Line]

"Black lights" emit Ultra Violet light. They make certain chemicals/minerals glow because the chemical/mineral absorbs the UV ight and re-enits visible light.

Neons "glow" because they have guanine crystals in their scales which diffract and reflect visible light. Put a Neon under UV and it will look dark.

UV lamps should not be over aquaria IMHO.

>>> every bit helps i suppose?

Yes, but remember the water absorbs light as it goes through it. Consider the electricity you are using to run a largely useless lamp.

 

[bob`_your_dog]

but will it blind or possibly kill anything, also can fish's even see in that light range cause they all seem very cautious and slow at night compared to my previous night light?

 

[lucky62]

Hey, i was just given a blue 4 foot light and ballast for R20 about $2.5 and i was wondering, all it has written on it is F40 T8 BLB 16, no name or model.
It's a very dull blue almost purple and isn't very bright at all, i was told it was for plants but i would like to use it as a night light? Are they usually very dim? or is it just old and lost it's strenght, cause compared to my other 40w's it looks like about 10watts

maybe a blue moon type reef light , for salt water set ups , I have one for my freshwater tank . I like the way it makes my fish look [ with other , brighter lights ], mine doesn't do a thing for my plants , but if the light is left on to long it will cause algae to grow on everything . I turn it on in the evening for an hour or 2 .