LED light penetration

[Defect]

Hello everyone,

I have a quick question. I am going to be getting LED lighting for my tank. Tank dimension 24x22x22 and the opening is 17x15 or somewhere close to that the fixture will be roughly 16x10. I want to have the lights about 8 inches off the top of the tank which I assume is going to be hitting the acrylic in some parts before hitting the water. Someone told me that LED lights will penetrate through CLEAN acrylic and just wanted to see if anyone had experience with this or not.

Thanks in advance,

Aaron

 

[reeffirstaid]

LED lights, like all other forms of lighting, will penetrate though clean glass or acrylic, even at the 8" mounting point you mentioned. Like all forms of lighting, some spectrum absorption occurs, whether or not you use glass or acrylic. The cleanliness of the acrylic, will play a role in how much light makes it into the aquarium. IMHO, the only LED light to buy, as of right now, is the Ecotech Radion. They are pricey, yet Ecotech is the only company that has made the full capability of LED lighting possible, and not just created a lower wattage Halide replacement.

 

[TJ's Reef]

There are several full spectrum LED fixtures available that are far less spendy than the Radion, though quality units not a stand alone by any means. Besides a budget it also depends on what you intend to keep Coral-wise and if you have or intend to purchase a non-proprietary controller (Apex / Elite etc...) or not.

Cheers, Todd

 

[Defect]

Thanks for the responses,

I was planning on going with the Reef Radiance Lumentek 120 pro so I can program it. I would like the Radion but more then twice as much. Only SPS I would really like to keep for now is going to be monti's.....I say that now but I'm sure I will get hooked on some other SPS as well. Zoa's, and chalice will also be going in eventually.

 

[TJ's Reef]

The RR Lumentek 120 will grow anything you like in your tank no problem even at 40-50% overall output. It is one of the full spectrum fixtures I recommend if not building your own.

Cheers, Todd

 

[Defect]

Thanks again Todd really appriciate the help.

 

[Hurricane Aquatics]

LED lights, like all other forms of lighting, will penetrate though clean glass or acrylic, even at the 8" mounting point you mentioned. Like all forms of lighting, some spectrum absorption occurs, whether or not you use glass or acrylic. The cleanliness of the acrylic, will play a role in how much light makes it into the aquarium. IMHO, the only LED light to buy, as of right now, is the Ecotech Radion. They are pricey, yet Ecotech is the only company that has made the full capability of LED lighting possible, and not just created a lower wattage Halide replacement.

Radions are very good LED's, but that statement is just not true in any shape or form. Ecotech has not done anything special with LED's in any way. The one thing they did correctly on the Radion Pro series, was incorporate the 405-420 range of LED's. That range is single handedly the factor for coral growth in LED's.

You can get fixtures that lack that range of LED's and they will work, but when you add that spectrum, coral growth and color skyrockets.

Again though, I would suggest the Radion Pro to about anyone as it is a very, very good LED. Ecotech did nothing special though when it comes to the innovation of LED's.

 

[Ron Reefman]

Radions are very good LED's, but that statement is just not true in any shape or form. Ecotech has not done anything special with LED's in any way. The one thing they did correctly on the Radion Pro series, was incorporate the 405-420 range of LED's. That range is single handedly the factor for coral growth in LED's.
You can get fixtures that lack that range of LED's and they will work, but when you add that spectrum, coral growth and color skyrockets.

Where does that bit of info come from?

Coral growth is based on the availability of food for the coral. The coral gets most of it's food from the zooxanthellae it keeps. The zooxanthellae use photosynthesis to feed themselves and grow. Most zooxanthellae use light spectrum from 400nm to 480nm and some in the 640nm to 660nm range. So what makes the 405nm to 420nm spectrum so special? Do you have any science you can point too? I'm not saying you are wrong, I'm just asking for some science. I've read a lot about coral, zooxanthellae and photosynthesis, and I haven't seen any statements like the one you made. It may be completely true, but I'd like to read about the science behind it. A link to an article with a serious author would be greatly appreciated.

An article at Advanced Aquarist stated: "More recent studies show that excessive low UVA (under 420nm) and especially UVB radiation can actually bleach coral, so the use of blue lighting under 420nm should be avoided!"




To the OP:
The light will pass through the acrylic better than it will glass (it's clearer than glass). You need to keep it clean and glossy. Glass will affect spectrum more than acrylic as glass has a greenish tint that will change the spectrum some. The total amount of light will be reduced a little bit. I have a 1/4" glass center brace that is old and etched to the point of looking like frosted glass and it reduces the PAR of my leds from 1040 at the water surface to 800 at the surface under the glass. That's about a 25% reduction. If you are really interested, I can test the loss due to clear acrylic (I have lots of it). Just tell me how thick it is?

 

[Hurricane Aquatics]

Hi Ron,

I have no "science" to point you to. I do have, however, real world experience that proves it to me.

I have owned EVERY fixture on the market when it comes to LED's. I mean every fixture. The ones that lack that spectrum are just not on the same page as the ones that have it.

You can take any fixture out there that does not have that spectrum and put it on your tank. Leave it for a bit, then stick a fixture on that has that and watch how your corals respond.

Oh and as far as science is concerned, what do Metal Halide's emit that LED's do not? One answer, UV. LED's do not emit UV of course, but they have that color spectrum that imitates it.

 

[Defect]

Ron,

I would really appriciate a test on the acrylic that would be fantastic. The acrylic is going to be 3/8 of an in thick.

Thanks,

Aaron

 

[TJ's Reef]

Most of the newer Full Spectrum LED fixtures and even a few of the primarily 450-460nm Blue with Cool White units incorporate Violet 410-420nm emitters now. IMHO/IME this is not for Coral growth but for added fluorescence of Coral pigments. Photosynthetic needs in this range are minimal at best. True UV below 380nm is unadvised unsafe and rarely even possible for our Reefs as the protective glass shields/envelopes on MH and Fluorescent lamps block this range quite effectively. I/you can grow beautiful Coral (shown under White light) with just 460nm Blue and 625nm Red emitters in a 2-4:1 ratio. Personally along with a nice mix of Cool Whites I like the broader range of Royal Blue/Blues 440-485 touch of added Green/Cyan 500-525nm and Red 625nm plus the fluorescing POP of the Violet 410-420nm . The preceding recipe is from my DIY build and mimics a Phoenix 14K lamp the closest I could in all the best parts with very little garbage light in the 540-580nm range. This is my Corals coloring from above taken just a few days ago, 2+ years under this blended spectrum.





​Cheers, Todd

 

[TJ's Reef]

Aaron, the acrylic should have very little affect on the LED light for your setup. My tank is constructed 3/4" acrylic with a 4" center brace and no issues what so ever.

Cheers, Todd

 

[Defect]

Thank you everyone. Todd your tank looks great!

 

[Ron Reefman]

Hi Ron,

I have no "science" to point you to. I do have, however, real world experience that proves it to me.
I have owned EVERY fixture on the market when it comes to LED's. I mean every fixture. The ones that lack that spectrum are just not on the same page as the ones that have it.
You can take any fixture out there that does not have that spectrum and put it on your tank. Leave it for a bit, then stick a fixture on that has that and watch how your corals respond.
Oh and as far as science is concerned, what do Metal Halide's emit that LED's do not? One answer, UV. LED's do not emit UV of course, but they have that color spectrum that imitates it.

MH does make UV, but it doesn't get to your coral. Either the bulbs use glass that blocks UV or the glass between the bulb and the water blocks UV. Sorry but that shoots down that theory.

And 400nm to 420nm violet leds (sometimes called UV) are not UV and don't imitate UV. UV is 400nm down to something in the 300nm range and is invisible to the human eye. 400nm to 420nm is not imitating UV, it's violet and both our eyes and the coral 'see' it as violet.

And if you can't pull out some science to back up your statements, then just to be fair to those of us that try to use science, you should state your points as being your opinions.

 

[Ron Reefman]

Ron,

I would really appriciate a test on the acrylic that would be fantastic. The acrylic is going to be 3/8 of an in thick.

Thanks,

Aaron

I'll pull out some clear 3/8th acrylic later this morning and test it for you.

 

[Velodog2]

TJ - beautiful corals! Could you be a bit clearer on exactly how many emitters of each wavelength you settled on for that effect? I like the lack of blue tint but still getting a good pop from the colors. I am anticipating rejiggering by DIY LED sometime soon and need a direction.

 

[Reefing Madness]

The only problem I have with using Acrylic and a SW tank, is that over time the acrylic will get buggered, and slowly the light output through there will dwindle down. I hate those plastic lenses over lights. Same thing will happen using the acrylic.

 

[Ron Reefman]

Ron,

I would really appriciate a test on the acrylic that would be fantastic. The acrylic is going to be 3/8 of an in thick.

Thanks,

Aaron

Aaron,

Here are the results:

no acrylic..........3/8" acrylic
110..................105
230..................210
410..................375
660..................605

Looks like a 10% drop on average. BTW, this was brand new acrylic with the liner just removed and wiped down. I hope that helps?

Ron

 

[Defect]

That does help very much not only for me but for anyone else that was wondering.

Thanks again Ron,

Aaron

 

[TJ's Reef]

Good stuff Ron, we make a good 'Lighting Team' as often on the same page though 3500 miles apart diagonally across the whole country...lol

Cheers, Todd