[scubadude]

I put a couple of black lights on my new canopy and They will basically be for short term visuall effects at nite but I was wondering if anyone else has tried blacklights as a reverse daylight on main tank as moonlight. all input appreciated! For those of you who havent tried shining a black light on your tank you should try if you have access to one.....and if your really feeling psychedelic then you can go to the next stage and throw a strobe light into the mix

[ravenmore]

Scuba,

I read a while back that black lights were supposed to be "bad" for corals. Never understood why. They only half decent explanation I heard was UV radiation. That doesn't seem like a problem to me because:

Most corals have protiens specialy designed to protect against UV light.

Water blocks some UV light naturally

Sorry, no way in heck can a 20 watt black light put out as much UV light as the sun midday on a shallow reef.....

However, I don't know if it has any benefits for corals either, although they often seem to be able to take advantage of wavelengths in the visible and near UV wavelengths....although in your case it doesn't matter as you're doing it for you not for them.

-Mike

[scubadude]

Originally posted by ravenmore
although in your case it doesn't matter as you're doing it for you not for them.

-Mike

I seem to remember some sort of post like that too.....I havent been using the lights much...maybe 1min at a time...1-2x a week Im not gonna turn them On much until I found out what the scoop is....I dont want it to hurt my corals/fish!

[icemark]

Back in High School (20+ years ago) I did a science project in that I grew Brine shrimp in a standard lighted evnviroment (solar lit), and in an enviroment that only had black light.

There where no differences in yeild, or size of growth between the two. Although it should be noted that I never did breed either batches of Brine Shrimp, so the long term effects could be different.

The only other difference was that the tank lite by the black light needed a minor amount more feeding as algae didn't grow as it did in the tank lit by sunlight. I think this was from the lack of "proper wave length" light as I have discovered in this hobby.

This was using a 60watt incandescent Black light bulb with no additional sheilding (other than the bulb itself) as the primary light source over a 5 gallon tank.

From that I would conclude that black light would be safe for higher level animals such as shrimp or crabs, although more testing would be required to see if it did affect reproduction.

Today in our tanks, I don't know if I would put the BL on all night, but for an hour or two (after the sun set, so to speak) I couldn't see affecting anything.

[mountainreefer]

I have heard that it can "burn" certian corals. That being said I have a friend that runs one (1 bulb n/o flourescent) for "moon light" on his tank....runs it for about 3 hours a night with no adverse effects. It is a neat look too.