Near UV LED's

[TropTrea]

I have exerimented in the past with near UV LED's in the 380 to 410 nm range and was very unhappy with them. However I'm still looking for something with a shorter wave lenght than the 454 Royal Blues to suplement with. What would be ideal would be a 435nm LED but I doubt if that animal exists. I have seen notes though of individuals that used 410 nm and 430 nm LED's. Does anyone have info on who manufactures LED's in the 420 to 430 nm range. Or any links to where I can find some preferably on star mounts?

 

[pnavarro170]

im looking into this also. first off what was it that you were unhappy with and why ?

i just ordered a maxpect razor that comes with 410/420nm leds, i think they are necessary for corals to retain their color. but i dont know for sure untill i try em.

I would love to go with a radion pro but a bit out of my price range at the moment. that one comes with 415nm leds and separate 405nm leds.

Im even thinking of adding an ebay pendant style uv led thats 20w of supposed 400nm spectrum to add to my razor.

 

[E Rosewater]

Steves LEDs has a 420nm LED. I have 15 of them in a 113 LED build. I don't notice much of a difference from them, I wish I had put a few more of them in. It's a good spectrum to have for photosynthesis though.

 

[TropTrea]

My experiece earlier with two different UV led's I tried were that everyone asked why are the lights on my tank so pink? I was only using them in a ratio of
1-near UV
2- Royal Blue
2-True Blue
1- Neutral White

I pulled the UV's and was much happier without the pink tint especialy on my sand bottom.

Besides this I did considerable research on how corals react to various parts of the light spectrum. I found that in nature there is basicly no light at shorter wave lenghts than 400 nm reaching the corals. The strongest peak of light is roughly 440 nm in nature but is strong in the range of 420 to 480 nm. Light at 380nm or shorter is extremly detrimental to all living cells and even in small dosages now is said to be a prime cause of skin cancer.

So with my present lighting with my blues being at 454 nm and 460 nm the real spread is between about 444 and 470 nm. This leaves a gap between 420 nm and 444 nm I'd like to fill. Ideal in a perfect world a 432nm LED would be ideal for this.

 

[Whitebeam]

I seem to remember that ac-rc do a 430nm 20W multichip if that's any use. Quite expensive though :-(

Peter

 

[TropTrea]

Yes I did get to the page everyone was pointing at. The 420-430 nm LED they offer seems to be very close to what I'm looking for. However on some threads I was told to keep the ma lows since the plastic UV protection lens does melt. I'm running my other LED';s on this new build at either 1,500ma (blues and royal blues) and my whites at 3,000ma. So I will have to run these on a seperate driver. Will probably use a 350 ma Driver on them since I do not want a lot of light in that range.

My original plan for my 120 gallon was to run
70 Watts of Neutral Whites (7-10 watt chipos)
60 Watts True Blues (12-5 Watt Chips)
120 Watts of Royal Blues (24 -5 watt chips)
30 Watts of Atinic 420-430 (30- 1 Watt chips)

I will probably back down on the Atinics initialy running 6 at 350 ma to see how it balances my color. I still have that fear they will push things pink on my like the prior near UV chips I used did.

I also do not want to pull the plastic lenses from them as they do act as UV protection and several expert claim that light under 400nm is more detrimental to corals than it is benificial.

 

[megadeth72]

I'm using 420nm violets, and they do make a big difference, I have one red acro that's green in my tank, in 2 weeks it's turned pink and still going

advancedaquarist has an article that details quite a few nm peaks that excite coral floresce and one of them is 420nm to excite 620nm and I think that's what's working on the acro I have

 

[Dave Thebrewguy]

So with my present lighting with my blues being at 454 nm and 460 nm the real spread is between about 444 and 470 nm. This leaves a gap between 420 nm and 444 nm I'd like to fill. Ideal in a perfect world a 432nm LED would be ideal for this.

I'm using a mix of 410-420nm violets and 440-450nm RBs (both from Steve's LEDs) to fill in this part of the spectrum. This is in addition to the usual 450-465nm XT-Es, 460-470nm blues, neutral and warm whites, all in a 1:1:1:1:1:1 mix and I had no sign of any "pinkness," just the opposite, I had too much blue. The 410-420nm violets peak at 417nm, not quite the 430nm you're looking for but certainly a helpful wavelength.

 

[zachts]

Rapid LED is winning my vote right now. I have yet to have one burn from them!

I have however burned up every other one available. Just got some new ones from Steve's though and they are much beter quality/brighter than the previous batch, they look blue'er when compared next to other violets. Also I'm assured these will not burn up at 700mA, but time will tell.

The ones from Rapid can easily handle up to 700mA

mcgyver if you keep posting banned sites you will get this tread closed and youself in trouble. personally I wish the filter would just say "CENSORED" and link to an explanation but that is not how it gets done its seems.

 

[TropTrea]

I'm using 420nm violets, and they do make a big difference, I have one red acro that's green in my tank, in 2 weeks it's turned pink and still going

advancedaquarist has an article that details quite a few nm peaks that excite coral floresce and one of them is 420nm to excite 620nm and I think that's what's working on the acro I have

I'm not sure if was advance awuarist or another site that ran a series of articles on florescense and photosynthesis in corals and there actual effective wave lenghts. I created a chart from these articles and have well over 100 chemicals listed. Of these roughly 60% requrire light between 430 nm and 460 nm to excite them. It goes up to roughly 90% between 420 nm and 510nm.

An interesting thing in my experiments I have an acro that under just neutral whites looks blue gray, under just 460nm blues looks bright yellow, and under just 454 royal blues looks bright green. But when they are all are on it picks up an extremely bright blue green look. There are probably at least 3 chemicals in this coral being excited by different frequencies and emotting light in anywhere from 3 to 6 different frequencies. The eye inturptes this light combination and interestingly everyones eye is not identical so it appears slightly different to different people as well.

 

[tomservo]

Dennis, be careful of which 420nm LEDs you buy, it seems some of the cheap ones have lenses that degrade under the intense near-UV. I've seen a few do this, ones from that snakey place are confirmed to do it if run fairly hard.

I recommend led fedy, they have 410-420nm and I believe also 420-430nm, but most importantly they have them available with 2 chips per star, so even driving them at 700ma is acceptable. Email their sales lady, Ava, and ask about the 420-430nm. The price is pretty competitive and I've been very happy with their product; no lens darkening to date.

That's cool about the coral; I've noticed this sort of thing, too.

 

[zachts]

Dennis, be careful of which 420nm LEDs you buy, it seems some of the cheap ones have lenses that degrade under the intense near-UV. I've seen a few do this, ones from that snakey place are confirmed to do it if run fairly hard.

they will probalby do this at lower currents, it'll just take a lot longer. a year instead of a few months perhaps. the damage is still taking place just much slower. I see the same thing happen with 5min. epoxy I've used to glue on lenses and attache acrylic splach sheilds. the epoxy on the inside that gets hit with violet turns brown. what's on the outside and doesn't get hit with violet light stays clear, for what that's worth.

I recommend led fedy, they have 410-420nm and I believe also 420-430nm, but most importantly they have them available with 2 chips per star, so even driving them at 700ma is acceptable. Email their sales lady, Ava, and ask about the 420-430nm. The price is pretty competitive and I've been very happy with their product; no lens darkening to date.

What current are you driving yours at and for how long have they been running, heatsink set up etc? thanks!

'side note' those two chip leds scare me a bit since they are almost always two 1 watt leds wired in parrelel. unless they have told you otherwise. the fact that they list output in lumens not mW makes me wonder also. you can't measure violets or royal blue in lumens. anyway, just my humble observation.

 

[Eud]

I'm planning to buy some of those two types of violets for my upcoming build. Apparently the problems with the browning on the little domes attached to the chips has been solved, and they now say that you can run at least the solderless ones which I think are a newer batch at 700mA without problems. That's what they say.

Also, they post spec sheets and I don't see much in the UV range for the higher of the two, so I wouldn't think you'd have to worry about the protection the lenses provide.

 

[zachts]

megadeth,

Also, they post spec sheets and I don't see much in the UV range for the higher of the two, so I wouldn't think you'd have to worry about the protection the lenses provide.

I'ts that little "not much" that causes the problem with the lenses degrading and turning brown. UVA radiation clasification starts at 400nm so any little bit of light below this threashold will defiantely have a degrading effect on non stable plastics. (see the circled areas on the attached graphs. it may only be a few percent of total output in this range but remember that it is very highly concentrated and the cummulative effect is therefore greater.

I would suspect that even the 400 - 410nm peak output of many violets also has this effect. as observed by the epoxy i use in many of my fixtures browning where exposed to light from the leds while remaining clear where it gets no LED light hitting it.

I like the look of that spectral graph for the 430s, if it is accurate I may have to give them another try. Has anyone compared one of the 405's with one of these 430's side by side to see if there is acctually a difference in color?

 

[megadeth72]

I run a glass lens anyway and mine do not have that little glob of plastic on them

Sent from my SCH-I535 using Tapatalk 2

 

[Eud]

megadeth72, this is off the OP's topic, but what lenses are you using? Seems every LED vendor has their own lens and most of them don't specify the maker of said lens or any optical characteristics other than which if their products it will fit on.

 

[megadeth72]

borite glass lens

these are the 420nm's I use

http://spectralworkbench.org/analyze/spectrum/2590

 

[tomservo]

What current are you driving yours at and for how long have they been running, heatsink set up etc? thanks!

'side note' those two chip leds scare me a bit since they are almost always two 1 watt leds wired in parrelel. unless they have told you otherwise. the fact that they list output in lumens not mW makes me wonder also. you can't measure violets or royal blue in lumens. anyway, just my humble observation.

I made three similar fixtures using the fedy dual chips blues and in two fixtures, the pottery snake violets, and some from aquastyle. The ones from aquastyle and the serpent both have turned brown in ~6 months. If you're careful you can pop the lens off without damaging the chip and connects, and then cover with the appropriate type of silicone (alcohol cure electronics stuff like from ac-rc). These are all driven at 700ma.

The fedy dual chips ones are 3w emitters. They also do the same treatment to the 660 reds and some other colors as well. The nice thing is using the dual chips types, you don't have to worry about killing them running at 700ma on cheap drivers.

I've since moved to multichip arrays - my system now uses the old light over the frag tank, and that tank is growing algae. It's gotta be the neutral white emitter, since it's the same water in the system.

 

[vitz]

dana riddle is the one who wrote all of the great tech articles on light wavelengths, pigments, and photosynthesis y'all are referring to

 

[zachts]

I run a glass lens anyway and mine do not have that little glob of plastic on them

Indeed, I think those massive multi chip versions would bake my tanks!

for the rest of us I think the latest generation of smaller Silicone encapsulated Chips now being offered will solve the issue of burning. fingers crossed!!