LEDs - Well, this is interesting

[fixerupper]

Recently I've been unhappy with my TMC Aquaray LED lights.

I'll post my 'issues' with these lights another day. I was not pleased so I took them down and replaced them with MarsAqua 165w LEDs. These cheap 'sh*t boxes' have a strong following over at Reef Central so I though "why not?"

Now to the point:
I was working in very close proximity with the AquaRay while they were on at 100% for about 2 hours. I replaced them with two MarsAqua and fiddled with them for (while lit) for about 1 hour. Then (here it comes) I also installed a Kessil A360WE my wife bought me for Christmas in between the 2 Mars Aqua fixtures. I turned it on and started adjusting it. Oddly enough it got progressively dimmer as I was working on cable management.

As a matter of fact the entire tank was getting dimmer even with the other fixtures still on. WTF? So, I walked out of my fish room to get to the other side of the tank and I could barely see where I was going. Then it was obvious. My new eyeglasses with a photochromic option had gone as dark as I've ever seen them. Interesting, no?

I've always heard that the Kessils have true UV emitters but this really showcased that particular claim. To reinforce this (now obvious) theory I took my glasses off and held them under each fixture at 100%. My T5s were removed so I couldn't experiment with them yet.

MarsAqua - no change. Glasses stayed clear.
TMC AquaRay - no change. Glasses stayed clear.
Kessils - almost immediate and intense change. Glasses look like sunglasses.

While this really proves nothing as to how effective these lights may or may not prove to be, I found it very interesting. As an aside, the Kessil lights also look like they are providing less illumination in the tank at 100% (with my glasses off, lol) than the other fixtures. I've read that much of their output is at wavelengths that are difficult for the human eye to perceive.

I'd be interested to hear anyone's comments regarding Kessil's UV properties.

Cheers

[Myka]

That is certainly interesting, but I have no idea what it means.

[fixerupper]

TLR
Kessils make your glasses go dark

[WarDog]

Originally Posted by Myka

That is certainly interesting, but I have no idea what it means.

It means you need some Kessils.

[mike31154]

IIRC Kessil is one of few if not the only manufacturer that designs & builds their own LEDs. Been a while since I checked out their web presence, but the info is no doubt still there. They have ample reason to be proud of their product & make that known. Most other light builders use 3rd party LEDs.

[Ron99]

Kessil's have UV but barely. Around 390nm or 385nm IIRC. So in my opinion it's more a marketing thing than a real "UV" advantage. What might make the Kessil work well is the amount of light being put out around that range rather than the actual; wavelength. i think the Kessil has more violet than some other fixtures. One outputting the same amount of light at 405 or 410 might well perform just as well.

[Reefer Rob]

Interesting, now I have to find someone with photochromic glasses to come test my lights. I just re-configured my DIY LEDs on the weekend to have a much higher concentration of "violet" emitters. 410nm True Violet is the lowest LED, but I wonder if they would have the same effect.

[mike31154]

Originally Posted by Ron99

Kessil's have UV but barely. Around 390nm or 385nm IIRC. So in my opinion it's more a marketing thing than a real "UV" advantage. What might make the Kessil work well is the amount of light being put out around that range rather than the actual; wavelength. i think the Kessil has more violet than some other fixtures. One outputting the same amount of light at 405 or 410 might well perform just as well.

UV comes in different flavours(wavelengths), A,B,C. You probably don't want to be exposed to UVB or UVC for any length of time due to the potential health risks. Manufacturers of light fixtures available to the general public are no doubt keenly aware of that. Legislated marketing... The point is, Kessil does provide some UV which is generally acknowledged to aid certain coral growth.

[SeaHorse_Fanatic]

Great info on this thread. Convinced me to pull my Kessil A150 Ocean blue off my fw tank and attach it to my main reef to supplement the area where I'm going to try out some inexpensive SPS.

[Ron99]

Originally Posted by mike31154

UV comes in different flavours(wavelengths), A,B,C. You probably don't want to be exposed to UVB or UVC for any length of time due to the potential health risks. Manufacturers of light fixtures available to the general public are no doubt keenly aware of that. Legislated marketing... The point is, Kessil does provide some UV which is generally acknowledged to aid certain coral growth.

Yup. UV A is from 315nm to 400nm. So at 390nm Kessil is just barely into the UV A range. Most others have violet in the 405 to 420nm range. My point is that I'm not convinced 390nm spectrum makes that much difference for corals vs. say 410nm. The absolute output in the UV/True violet range appears to be higher in the Kessil lights so i think it's more a quantity vs. quality thing. i suspect that if you had more 410 or 415nm emitters and matched the output of the Kessils you may see similar results. But Kessil claiming true UV output is a marketing gimmick IMO as they are just barely in the range.