Mitras LX7206

[JNalley]

I have a question that may be hard to answer, but I hope someone here can help. @Vinny@GHLUSA hopefully has an answer.

I am considering buying a used Mitras LX 7206 from a seller here on the forums. But my question has to do with the True UV (380nm/385nm) LEDs. It will be going over a tank without a hood, and I have a 2-year-old who will be looking up at the tank and I know UV can be bad for your eyes, so I am wondering if I should be thinking of building a canopy before I install it, just so that she's not getting her eyes hit with UV.

Also, I've tried to find a recommended mounting height (off the surface of the water) but haven't been able to locate one, so if you could also give me that info it would be appreciated. It's going to be over a 35.43" L x 23.62" W x 22.44" H tank, and as I understand it, it's recommended/rated for 36x24x30 so this light should be plenty?

 

[ingchr1]

The LED channels are individually controlled, so you can just run it with the UV channel off. Eliminating your concern.

 

[Saltysav96]

I run 3 lx7’s over my reefer 525 with no canopy. I am short so I look into the light often.
i run my UV pretty high. And i have not noticed anything.
my fiancé hasn’t said anything about the UV. either. We also have 2 small toddlers .

 

[JNalley]

The LED channels are individually controlled, so you can just run it with the UV channel off. Eliminating your concern.

Part of the reason for getting these lights specifically is the UV, I was just wondering if the UV LEDs are powerful enough to cause damage to her eyes and if it's something I should be concerned with. But since I posted, I've continued to look online, and for the fun of it decided to look up the spectrum of a black light, which has a spectrum peak of around 375 and a total spectral output between 350 and 425, which I've looked at directly multiple times without issue, so I'm hoping it comes back the same here. Since they're already in a spectrum that seems ok, hopefully, their intensity is reasonably around the same.

I run 3 lx7’s over my reefer 525 with no canopy. I am short so I look into the light often.
i run my UV pretty high. And i have not noticed anything.
my fiancé hasn’t said anything about the UV. either. We also have 2 small toddlers .

Awesome, thank you so much, after some further searching this is along the lines of what I was hoping for

 

[Saltysav96]

I will say , i was working on a ATI T5 fixture one time trying to change a ballast and I ended up having to go to the Eye dr and get some drops for over exposure to UV. But that only lasted like a week.
but i never had an issue with the lx7’s
Ive been running them for about 2 years now on a different tank and just recently upgraded to this one

 

[Lasse]

But since I posted, I've continued to look online, and for the fun of it decided to look up the spectrum of a black light, which has a spectrum peak of around 375 and a total spectral output between 350 and 425, which I've looked at directly multiple times without issue, so I'm hoping it comes back the same here. Since they're already in a spectrum that seems ok, hopefully, their intensity is reasonably around the same.

Because black light is just outside what the human eye can detect - it does not looks very bright when you look into the light source - but it has a very high energy output - but you just not see it. This article can give you a hint. The thing is that the damage blue light below 450 nm can do - is not anything you will notice today - but in a 20 - 40 years time frame - we just not know. IMO - it is not good for a child to look directly into these light sources - not even black light.

Sincerely Lasse

 

[JNalley]

Because black light is just outside what the human eye can detect - it does not looks very bright when you look into the light source - but it has a very high energy output - but you just not see it. This article can give you a hint. The thing is that the damage blue light below 450 nm can do - is not anything you will notice today - but in a 20 - 40 years time frame - we just not know. IMO - it is not good for a child to look directly into these light sources - not even black light.

Sincerely Lasse

Well, I've read the article, and I've been using computer screens 90% of my day since the early 90's, and from the mid-nineties to around 2015 I spent nearly every weekend in raves with black lights and I still have 20/20 vision. I may be an exception to the rule, but at 41, going on 42 years of age, with still perfect vision, I think it may be less of a problem that is being expressed in the article. This current generation of scientists seems hellbent on scaring everyone about everyday things. That being said, I will still shield my toddler from its effects as best as I can, because I recognize that anecdotal evidence is not true science, and since I am not an Ophthalmologist it's best to err on the side of caution.

 

[Spieg]

My understanding is there is UVa, UVb and UVc... I've read that UVc is the one to avoid. Not sure if these lights produce UVc or not.

 

[JNalley]

My understanding is there is UVa, UVb and UVc... I've read that UVc is the one to avoid. Not sure if these lights produce UVc or not.

They do not, they're very narrow band UVA (385nm I think)... Black lights are also UVA (from 350+nm with a peak at 375). Reptile lights get into UVB (also damaging to us, skin cancer and other things), but only very specialized lighting goes all the way down to UVA (which is mostly filtered out by our atmosphere so we don't get much if any UVA radiation on earth, and it never reaches reefs as far as I know).

 

[ingchr1]

So, it's not certain one way or the other on potential harm to the human eye. At the same time, it doesn't appear to be necessary for coral health.

Corals don't require UV-A or UV-B to grow and many, if not all, don't need it to color up. We determined this back in the 90's at the coral farm, where we used metal halide lamps (Iwasaki 400w daylights) that had plastic splash guards which absorbed all UV (as determined by use of a UV radiometer). There is (or was) an aquarium LED light that used 365nm LEDs - I seem to think this was a BML lamp, but it's been a while. Many types of zooxanthellae can produce UV-B absorbing compounds (MAAs, or mycosporine amino acids). There are maybe a half dozen MAAs that absorb specific UV bandwidths, with the highest absorption at around 350nm or so. Hence, using lamps producing UV-B might be an exercise in futility.

Why risk it and run it at all?

 

[JNalley]

So, it's not certain one way or the other on potential harm to the human eye. At the same time, it doesn't appear to be necessary for coral health.

Why risk it and run it at all?

"Doesn't appear" is not the same as "unnecessary". In the wild, coral reefs are exposed to UV-A and small amounts of UV-B. There are no studies that currently exist about the effect of UVA and UVB on most of the biological processes within corals. However, it is shown in several papers that corals create a kind of sunscreen for reef inhabitants which seems to be directly related to UVA and UVB. There simply isn't enough evidence to state definitively one way or the other if they are useful or not for other functions (Digestion, Propogation, Photosynthesis, etc). Also, if we are to concede that coral was best grown under Metal Halide's and T5's, we must also concede that UVA was a part of that spectrum, while the Metal Halide's had Acrylic covers that blocked UVA, Actinic T5's also put out small amounts of UVA.

So does Blue Plus

and so do a lot of the different T5 Bulbs Available for our reef systems.

Interestingly, the UV in the 365 and 385nm range bring out colors unseen with the other spectrums of light, as shown by a few members of this forum already. Also, Kessil, Giesseman, GHL, Maxspect, ReefBreeders, and Orphek are all starting to include True UV in their lights. Why (as a company) spend more money on more expensive LEDs (UV LEDs are more expensive to make and as such are more expensive to purchase) if there is no benefit from it? One might argue "It's a marketing gimmick to get you to spend more money", where I would respond by saying "Maxspect Jump is one of the cheapest midrange lights on the market, competing with the cost of AI Primes, offering more wattage than AI Primes, with at least 8 more LEDs than primes, with full wifi control" and then I would ask, why are they spending more money to actually make less money? The cost difference between the two lights is $35 and currently in favor of AI, but there's a lot more than $35 extra worth of stuff in the Jump series lights (Did I mention they come with stiff metal mounts in the package for that price?). I would also ask why Kessil, who manufactures their own LEDs, go through the trouble of making UV LEDs to include on their dense matrix array and not advertise that they have True UV other than showing their spectral output? The marketing argument makes no sense because it's never really listed as a talking point feature, it's often just a background point on a data sheet.

I also operate on a "nature knows best" approach, while there are plenty of things that occur naturally that are harmful, and other things that are scientifically determined to be uncessary for 'x', we simply don't have any info suggesting one way or another in this instance, and the only way we can learn is if we start from the baseline (the basline in this instance being nature). We already do this with so many other things in this hobby such as water chemistry, we just haven't taken this approach with lighting because it's almost impossible to recreate the sun in its entirety, but, since that is the goal, I'd rather get close to what the sun does, than arbitrarily get rid of things because our current anecdotal evidence says we don't need it.