Anyone Thinking of Dumping LEDS and going back to Halides

[gbru316]

The UVA and UVB radiation are what causes the SPS corals to color up and reflect these wavelengths.

This isn't true. It's a common misconception based on an outdated study.

Metal halide lamps, while indeed producing UV light, are manufactured with built-in UV shields (in the case of mogul bulbs) or require external shields, in the case of DE bulbs.

While people DO refer to certain emitters as "UV," in most cases, they are referring to "near-UV" or "true violet." Emitters in the 400-430 nm range. The light in this range is better known, in this hobby, as actinic.

 

[asonitez]

After my Tank crash I took a lot of time and energy and decided to upgrade to LED's. I don't know if it ws the best decision. I have supplemented the LED's with T5's (ATI Blue+) So far I think they are doing ok but the verdict is still out. I have given them from last October to This Summer to prove themselves under optimal conditions to win me over. If not I'm going to go to T5's and sell off the Sol's.



DSC_0686 by Asonitez, on Flickr


DSC_0678 by Asonitez, on Flickr


DSC_0652 by Asonitez, on Flickr


DSC_0619 by Asonitez, on Flickr


DSC_0615 by Asonitez, on Flickr


Just as the T5's turned off I took this one. I thought the shadows were cool and scary


DSC_0649 by Asonitez, on Flickr

 

[meshwheel]

GBRU316,
Please tell me how and why this theory is wrong? And please show me some data explaining this. I have been in this hobby over 30 years.
Those deep rich metallic colors you see in SPS are reflecting portions of UV light off them.
Many people see this change, when switching from metal halide to LED, and then back to Metal halide again.
Metal halide bulbs do have protective shields, but sit under one for 30 minutes and let me know how your skin feels! YOU get sunburned. Just as you would under the sun.
Some metal halide bulbs come with warnings in their little direction sheets that come with them, just for this reason.
Metal halides/ T5's have a sterilization effect on the water too, helping to keep it clean.
Also, the UVB from them helps the skin to produce vitamin D. Which may or may not be benificial to corals. However, I would assume that it is.
There are LED's that are used for sterilization purposes. They are that strong in UV output. I feel the current LED fixtures are getting better, but are still lacking certain pieces to this puzzle.......

 

[meshwheel]

and don't get me wrong. I like LED's. I like the fact that you can save electricity and have a cooler running system. I feel that the LED's are lacking in the 4-400nm range of UV. And I feel this is key.
Maybe some are not. And some are. I have never owned them. But that cool running effect and lack of radiation just doesn't sit right with me.
I like the Kessil's and the Maxspect razor so far. The Radion Pro looks better. Have not seen it yet in person. I missed the last reef-a-palooza.............

 

[power boat jim]

Power boat Jim,
Tank looks great! Healthy too! I have a question: Have you ever worked on your tank under those LED's and gotten burned from them? You know, a mild sunburn.
Because I got to mess around with them first hand at some shows a few years ago when the spectrums and power where really weak.
You can get sun burned under a metal halide and T5's as I have workwed under both and it's happened to me.
I think the LED's lacked Ultraviolet radiation. Not sure if this has been corrected. I think it has in some of the fixtures. The UVA and UVB radiation are what causes the SPS corals to color up and reflect these wavelengths.
I am sure the older LED fixtures put out some, I just feel it was not enough. And I agree, the correct mixture is everything.
I know there are UV LED's that really crank it out to the point where your not even supposed to be able to look at them without damaging your eye's or causing irritation.
Acroporaddict,
Sounds like your getting that radiation you need now!

No Never been burned by the LED while working on the tank they just dont give off that much heat and 0 UV rays. I think you may be mistakiing a heat burn with sun burn from UV exposure from a MH bulb. I know exactly what you are talking about, singed the hair on my arm too many times! MH dont give off much UV with the outer shield in place. Crack that outer bulb casing and watch you corals fry. It is true what GBRU said about corals not needing UV. More recent studies have shown UV rays do not help color up coral. I just read it a few days ago myself. This is going to be a hard idea to get around since most of us thought different.

 

[meshwheel]

Jim,
I have been burned from mine. And mine are sealed behind glass. I think it's the UV coming from them. Yea, everyone has their own opinions. Mine are that the lack of UV from LED's is a problem. And I am wondering, as they burn down is the little bit of UV one of the first things to diminish?

 

[gbru316]

It is true what GBRU said about corals not needing UV. More recent studies have shown UV rays do not help color up coral. I just read it a few days ago myself. This is going to be a hard idea to get around since most of us thought different.

Thanks Jim. IIRC, I read an article in reefkeeping, which is currently down while the powers that be fix the RC servers. I'll look for the article I read when RK is available.

 

[meshwheel]

Does anyone have a spectrometer to measure these led's UV output??? And then measure again in 6 months. Then a year? Do any of the manufacturers post this infomration?
Inquiring minds would like to know......

 

[megadeth72]

who has run halides without uv shields? I Know I have not

I do know that most commercial leds are missing violet between 400 and 440 and IMO it makes a big difference, halides have it, and it's not filtered by uv shields

 

[megadeth72]

Does anyone have a spectrometer to measure these led's UV output??? And then measure again in 6 months. Then a year? Do any of the manufacturers post this infomration?
Inquiring minds would like to know......

I have one, but mine cant measure intensity like that, only color shift

 

[meshwheel]

Megadeath72,
You are correct in stating that 400 to 440 makes a big difference. And why? Becasue in the 420nm range, you get wavelengths of UVA!!!!!
And this is one of the reasons why you can get sunburned from them. hhave a old article I saved that I am looking for to post. Maybe I can find it. I think it was Aqualine Bushke that did the research and posted it years ago.

 

[megadeth72]

uv is below 400

 

[gbru316]

Megadeath72,
You are correct in stating that 400 to 440 makes a big difference. And why? Becasue in the 420nm range, you get wavelengths of UVA!!!!!
And this is one of the reasons why you can get sunburned from them. hhave a old article I saved that I am looking for to post. Maybe I can find it. I think it was Aqualine Bushke that did the research and posted it years ago.

UV is below 400 nm

UVA is 315 - 400 nm
UVB is 280 - 315 nm
UVC is 100 - 280 nm



400-420 nm is actinic.


With LED emitters being narrow-band in spectrum, a 420 nm "true violet" LED will NOT emit sub-400 nm wavelengths.

 

[meshwheel]

UV spikes up to 420 and probably higher. The sun is not constant and has spikes continuously. If you look at a metal halide bulb, they spike as well.
Here's a pretty good read. Some general but good metal halide bulb information:

http://www.ushio.com/products/aquarium/aqualite.htm

We all know too that carbon can play a significant role in what gets through the water to our corals. Hence, the different results for different people. I think I may run carbon in a reactor on my reef tank if I used LED's. Still mowing over it. Not quite ready yet, and if I do go with T5's or led's it will be the VERY last thing I buy!

 

[reefgeezer]

UV is below 400 nm

UVA is 315 - 400 nm
UVB is 280 - 315 nm
UVC is 100 - 280 nm



400-420 nm is actinic.


With LED emitters being narrow-band in spectrum, a 420 nm "true violet" LED will NOT emit sub-400 nm wavelengths.

Thank you. Remember everybody, if you can see it it is not UV. I would also be advisable to remember something from a Sanjay article from a long time ago. The human eye is not sensitive to short wave light.

 

[megadeth72]

actinic is some made up bs term

the 410-420 range is violet, below that is ultra violet, above it is the blue range

 

[meshwheel]

Aqualite 10,000K lamps produce the ideal balance of blue, white and red light in the spectrum to simulate daylight in the water. Our Aqualite lamps reduce the green light, a spectrum which can promote the growth of the “bad” algae that grows on corals.

UVC = 100–280nm: Most harmful and used in sterilization to kill biological organisms.
UVB = 280–315nm: Harmful and causes sunburn, skin cancer, and eye damage.
UVA = 315–400nm: Longer wavelength and less energy than other UV. It is the least harmful but still can be damaging to DNA and the human eye.
Black Light Blue Lamps = 368-371nm
Actinic Lamps = 420nm Peak: Although actinic lamps peak at 420nm they do produce wavelengths in the UVA range so UV protective safety rules apply.
Visible Light = 380–780nm
Photosynthetic Light = 400-700nm: The more peaks across this broad spectrum will give you the best photosynthetic performance.

 

[meshwheel]

Here's a great comparison. The LED is as you can see very flat. Very little peaks at all compared to a halide. A whole different animal.....

 

[grcforce327]

Thank you. Remember everybody, if you can see it it is not UV.

My blind friend can't see it,so I told him it must be UV! :dance:

 

[Shallow Planet]

I would never go back to Halides. LEDs are now just as cheap, last longer, seem to get better PAR, and do not have the issues of heating up your tank. LEDs for life.