Lighting Recap at Meeting

[nicks387]

I left the meeting early because I had to go to work but it seems I may have missed some good lighting info that has people saying they are getting rid of the Halides on thier tanks. What did I miss???

 

[s_kelley]

Sounds like I missed another good meeting, what are people saying?

 

[justintrask]

basically he measured the lighting output of t5 lighting in a 18" deep tank as compared to metal halides, and it showed that the lighting output was roughly the same. Also, he showed that certain corals that we have thought require intense lighting can survive at much lower lighting.

 

[Fried Clam]

Not only do they survive, but actually grow with much less lighting that previously believed.

 

[nicks387]

Oh, I see. So nothing that would make me go and ditch my Halides.

 

[SharkLover]

Oh, I see. So nothing that would make me go and ditch my Halides.

He did mention that providing too much light causes "term that i can't remember" where zoanthelias begin to reduce the amount of food they produce instead of plateauing. Thats the only downside aside from extra cost. Also that if you have giant clams, they won't grow under T5's but will be sustainable to at least survive. Also, Any paint on your back glass causes a reduction in the reflection of light on that surface of glass and therefore lowers par in that region of the tank (back wall for example).

HTH-

 

[Fried Clam]

basically he was saying that you don't need the amount of light that a MH gives off...except for a few things. He hasn't been able to keep Clams under the T5s and there are probably a few other things as well, but MOST corals would do fine under T5s.

This of course is simplifying his talk quite a bit, but that's the basic idea. And the reflectors that you use with the bulbs make a big difference as well.

 

[JasonandRay]

like acros hane thrive at 100 par

 

[JayM]

basically he measured the lighting output of t5 lighting in a 18" deep tank as compared to metal halides, and it showed that the lighting output was roughly the same. Also, he showed that certain corals that we have thought require intense lighting can survive at much lower lighting.

That's not what I got out of it, actually, IIRC, I think 200 PAR readings with T-5 were 3x higher at 600 readings with MH.

what it showed was T-5 with individual reflectors kicked a** as opposed to the single sheet reflector, (or no reflector) and from an efficiency standpoint, and that most corals could survive at 18" with a T5 fixture in a 75g.

Also, painting your tank back, or attaching vinyl, hurt the PAR readings significantly, and black was the worst color.

What it also showed was t5 lighting, in the most part, cannot support clams*

*This allowed me my cognitive dissonance for running over 1000W of MH on 3 tanks supporting my 9 clams

 

[deb b]

Also, painting your tank back, or attaching vinyl, hurt the PAR readings significantly, and black was the worst color.

I was not at the meeting; I just put a black background on my tank, it is the shiny background paper bought at LFS. I have T5's would you suggest I remove it? Thanks

 

[Gina McReeferson]

Moving to RT.

 

[delta]

I was not at the meeting; I just put a black background on my tank, it is the shiny background paper bought at LFS. I have T5's would you suggest I remove it? Thanks

Actually backround paper just taped on is not a problem. If you use anything to adhear it to the glass then it reduces the light output drastically. The type of lighting doesn't matter unless they are LEDs. The LEDs didn't even have enough spread to make it to the outer edges of the tank.

I will post the notes I took later tonight. It was a very imformative presentation.

 

[coralcor]

Actually backround paper just taped on is not a problem. If you use anything to adhear it to the glass then it reduces the light output drastically.

I will post the notes I took later tonight. It was a very imformative presentation.

cant wait to read them. i didnt get to the meeting.

 

[Fried Clam]

I was not at the meeting; I just put a black background on my tank, it is the shiny background paper bought at LFS. I have T5's would you suggest I remove it? Thanks

Deb, if you just taped the paper backing to the tank, it won't have an effect on the PAR readings. He tested this and only found that it had an effect if he wet the background paper and stuck it directly to the glass but not when he taped it as tightly as he could.

 

[JohnK]

The word for when corals get too much light and start to grow less/zoanthale produces less food, is photoinhibition. Essentially the zoanthalle produces more and more food with more and more light to a point, but at that point they start to slow down, and farther past that point production will actually decrease. (Calfo talks about this in his propagation book)

Second on what Jay said, He showed MH putting out much more light, but also that the levels produced by T5's tested were perfectly adequate for all sorts of corals including numerous SPS.

The thing I found particularly interesting was the thing about light reflection (and this was why the PAINTED backgrounds are bad). He said the super simplified explanation was something to the extent that when ever two clear but different things meet there is reflection. ie water touching glass reflects light, and glass touching air also causes reflection.
Because of this, he found that when shining a light into a fish tank full of water, the point where the water meets the glass reflects light back into the tank, and the other side of the glass where it meets the air also reflects light back in.

Because of the above;
-painting the back glass will eliminate the reflection effect coming off of the outside of the back glass (enough that it showed dramatically in his light distribution graphs). He also stated that as long as the background isn't directly touching (painted on, or stuck on with adhesive) it DOESN'T cause the loss of reflection.
-This glass reflection effect also favors T5 over MH as the distribution of light from a point source doesn't bounce as much light off the glass and back into the tank.
-Letting the glass get dirty actually will decrease light intensity in the tank (so go scrape all that coralline...)

If you want a background, don't paint it or use stick on backing, BUT you can hang a curtain behind the tank, or any other option that still allows there to be air against the glass.

 

[deb b]

Actually backround paper just taped on is not a problem. If you use anything to adhear it to the glass then it reduces the light output drastically. The type of lighting doesn't matter unless they are LEDs. The LEDs didn't even have enough spread to make it to the outer edges of the tank.

I will post the notes I took later tonight. It was a very imformative presentation.

Great Thanks Greg!

 

[deb b]

Deb, if you just taped the paper backing to the tank, it won't have an effect on the PAR readings. He tested this and only found that it had an effect if he wet the background paper and stuck it directly to the glass but not when he taped it as tightly as he could.

Thanks I have it taped so all is good Thanks

 

[saltwaterB]

I will still continue to paint the back of every tank I ever set up. I have been keeping corals in these tanks for over 10 years, and they have all done excellent. I really can't see that being any significant difference. do we really need that little amount that might be lost??? I think a black painted background looks the best, therefore that is what I will do and recommend. Are we really getting that geeky that we are going to remove backgrounds from our tanks for a small amount of PAR from reflection... I mean seriously, I think we just need to take a deep breath and relax...lol


99% of this hobby is about personal preference. It all works, just go with what you like (lighting, rockwork, sandbed, flow, backgrounds, supplements, testing, etc) As long as we understand the basic principals and fundamentals of the Ocean, research and understand the requirements of the animals we plan to keep, and provide the best environment possible. We will be successful.

 

[JohnK]

I totally agree with you B,
but FWIW it was quite remarkable how much you could see it in the graphs he had. Over and over the back of the tank would be a large percentage lower in PAR.

This is just one more way to pinch out every penny of electricity possible and be as green as possible about this crazy hobby.


In the end this just proves that I've always been right with my black curtain behind the tank

J/K
jk

 

[nicks387]

Good info. Thanks everyone. I wish I could have stayed. I have black tint on my background so I can still peak thru from the back but I may rip it off now.