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evoracer

LED and UV. What's the REAL story?

Rating: 7 votes, 4.86 average.
12 Comments
by
evoracer
, 11-13-2010 at 05:18 PM (5012 Views)
So I was intending to pick up an LED fixture at RAP last month in Southern Cali, but was discouraged by much conflicting information about the light output produced by them. The biggest concern, or rather question, I left with was whether or not LED's produce usable UV radiation.
From my research I have found the consensus is that SPS coloration is all but dependent on UV in the light being provided to them. From what I have read the theory is that as a response to UV SPS produce their slime coat to protect themselves (think sunblock). The slime coat is what is responsible for the coloration of the coral (or at least the fluorescing, appealing coloration reefkeepers look for). So without UV in the long run SPS will brown out.
At the show there was a vendor who claimed that no LED fixture on the market produces UV. He had a UV meter, and was measuring MH, T5s, and his own LED tubes, showing all but the LED produce UV. He then tested his UV LED tubes, showing they do indeed produce UV. Now obviously he did not get specific on what wavelengths he was measuring for, even when I asked. I took this information to some of the other vendors, who in turn claimed they all have been keeping everything from clams to SPS to zoanthid to Acans under LED only for months to years without any coloration issues, and reported outstanding growth. Some even claimed his testing was faulty, or deceptive, as their equipment does produce UV. One vendor stated all LED produce some UV, but could not specify how much or of what spectrum.
So I guess my question would be to any lighting experts: what's the deal? Do LED produce UV? If not could you supplement with a single T5 UV bulb? I really want to go LED but would hate to invest in a product that can't keep my tank happy.
Thanks!

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Updated 11-20-2010 at 02:16 AM by melev

Categories
‎ Lighting

Comments

  1. dread240's Avatar
    You know, I'm kind of in the same boat you are, and with the amount of uncertainty on it all still, I just opted to go with MH/T5 combos instead. I was really close to building 2 LED pendants for the tank, each one would have ran about 500 a piece, but there were so many what if's I decided not to go with it
  2. Gozer_1's Avatar
    Seems to be the state of the LED market. Every where I look I hear the same, "I'm just not sure". My inner geek and my love for DIY is really pushing me to try them though. I have a pretty low light tank so I'm not to worried. For me it's all curiosity. In the end, I just bought new bulbs for my old CFL Orbit fixture. Guess I'm not ready to try LEDs either.
  3. Eric B's Avatar
    I have been planning a DIY build of LED's for my display (180 Gallon) but still doing some smaller LED DIY project's to practice and perfect the way to incorporate it over to my larger build. Most MH do produce some UV and I think it is in the 350 NM range, I have not seen a T5 bulb that will produce UV except the ones design for UV sterilization which is UV-C in the 250 NM range (You don't want to place this type in a fixture over your tank only in a sealed container from view). The only UV any LED's produce are from UV specific LED's the normal white and blue produce no UV. Some fixtures that I have seen recently are starting to add these UV producing LED's into there fixture's and I do think it is beneficial as these are UV-A & B wavelengths not UV-C. In my build I am incorporating White, Blue(2 different shades), Red, Green and UV in the 350 NM range which is a purple color similar to a black light. Of course most of the LED's in the fixture will be white and blue.......Hope this helps a little as I will be posting some pics and more info as I go through the builds and as I learn more about the LED's.

    I have also been researching a DIY UV sterilizer built out of 250 NM UV-C LED's but these are pricey in this range and don't know if it is worth it yet!
  4. evoracer's Avatar
    Well the vendor did show me UV reading on his meter from a T5 fixture. About half that from MH. I wish I noted the exact measurements. His UV LEDs were displaying roughly half again of the T5. I have been thinking of building my own fixture as well, with dimmable power supplies and some red and UV LEDs. The problem I am having is finding UVs, and deciding how many I really need (or rather how many would be too many).
  5. Eric B's Avatar
    All readings I saw at MACNA on T5 fixtures this year showed no UV but the LED fixtures with UV LED's and MH were about the same UV output (That was just what I saw with my own eyes). The total number of UV LED's is probably just an opinion from each person you talk to about how many you need and would only be a guess on my part currently as I am still trying to figure it all out myself. I just know that I don't want just blue and white because you are missing out on the other spectrum's that exist. All the colored ones I use have been purchased out of China except for the UV LED's. If you do a google search on 350 NM UV LED's you should find some and I believe there is a company out of FL that sales them and they are in the $30 range each. You might be able to find them cheaper if you do a more detailed search but that was how I found them to start with. Good luck with your build and I will post some pics as soon as I have something together that is worth looking at......I am using a 500 watt power supply from a computer for power and I have a friend locally who is also working with me on this project and he knows how to wire them through a resistor or rheostat for the dimming feature. I will eventually hook all through my aquarium controller and just have it do the dimming when I tell it to.
  6. evoracer's Avatar
    Sounds cool. Yeah I'm not so sure the vendor was telling the "whole truth" with his readings.
  7. Eric B's Avatar
    Let me know how the build goes and will keep you informed on my end as well....Not going to do too much before the first of next year though!
  8. 2Quills's Avatar
    I'm on the fence with this subject as well. I have a build in progress and have plans to DIY my own fixture. I've been reading all of the stories about SPS and such losing some color. I also think it would be benificial to incorporate some U.V. LED's into the rig.

    I was speaking with a friend of mine who witnessed a demonstration one a 180G tank with LED's. Ofcorse we all know how colors pop under the blues. But he said that the guy who was doing a demonstration had a small retro fixture with 6 u.v. led's and when he turned them on over the tank everybody in the room's jaws dropped from the spectacular colors it produced. My buddy said he seen colors in corals that you'd never know where there if it wasn't for the u.v.

    But with that being said I think the key would be to find the right ballance of u.v. to incorporate into a fixture. Too much u.v. can be a bad thing and not enough won't give you the look that you're after. I was planing on possibly incorporating a total of 4 u.v. leds into my build to put over my 120G tank. Ofcorse all of my colors will be on seperate dimmers for fine tuning the output of the led's without having to adjust the height of the fixture.

    SuperBrightLED .com sells u.v. leds as well as a wide range of led products.
  9. 2Quills's Avatar
    Drats, the dreaded double post!
  10. Eric B's Avatar
    Let us know how the 4 uv's work out for you very interested.....
  11. evoracer's Avatar
    And thanks for the link! I hope to start my build after the holidays.
  12. Eric B's Avatar
    You can also check out this site http://www.satistronics.com/ if you are buying LED's for a DIY build. This is where we purchase from and they ship pretty quick and have never had a problem.