Do LEDS wear out

[Bouldereefer]

I have 4 Gen2 radions that more than cover the space in my tank. I am about to restart my aquarium after a move. I would like mixed tank.
I have read LEDs will wear out with time. However using a PAR meter they still put out 400 plus. Am I fooling myself that they are still fine. Does the useful spectrum fade with time?
Thanks

 

[jason2459]

Sounds fine to me. Yes, they will eventually fail.

 

[ScottJ]

I think when they fail, it would be due to a circuit failure, and the light just wouldn't turn on. Or be really, really dim, or really, really bright. Like a problem in the control circuitry. Or half the LED's lit, etc.

I could be wrong, but I don't think the spectrum would change with use over time.

 

[BeanAnimal]

LED output diminishes over time, but at a much lower rate than fluorescent or halide lighting. They may slightly shift spectrum as the phosphors change over time as well. There are MANY variables that dictate the rate of degradation, but in general it boils down (no pun) to heat management in the fixture vs the output intensity and design. Use them until the PAR and/or COLOR rendering don't please you. For most people running a well made fixture at some percentage less than all channels at 100% all day, this will be a decade or three before output drops ~20% and even then they will still be very usable.

 

[ISpeakForTheSeas]

I think when they fail, it would be due to a circuit failure, and the light just wouldn't turn on. Or be really, really dim, or really, really bright. Like a problem in the control circuitry. Or half the LED's lit, etc.

I could be wrong, but I don't think the spectrum would change with use over time.

Yeah, my understanding is that various components of the light fixture typically fail before the diodes themself, but if they don't, the diodes will lose some of their power/efficiency eventually (for the long, storytelling in layman's terms for why, see the thread below):

An Inherent Flaw in LED lighting-- Why all LED fade, and what you can do.

Long post but, here we go. I'll start at the basics. In layman's terms, essentially when a LED is created, there's a substrate that is laid down, usually a crystal lattice. This substrate sits between your LED and your wafer from the chip. This substrate sits on top of that wafer and...

www.reef2reef.com

 

[oreo54]

I have 4 Gen2 radions that more than cover the space in my tank. I am about to restart my aquarium after a move. I would like mixed tank.
I have read LEDs will wear out with time. However using a PAR meter they still put out 400 plus. Am I fooling myself that they are still fine. Does the useful spectrum fade with time?
Thanks

Pretty picture says a lot. Now this is JUST for the LED. As mentioned above things like capacitors ect. can fail much earlier.
Everything depends on heat..
Industry defines their "replacement point" at when lumen output drops below 70% of original.
Technically they want (or did) move to 80% but that is irrelevant to this story.
Well so is lumens but another story.

LM80 in LED lighting

LED lighting quality assessment, LED chip performance, LED lifetime. Check it out!

www.enlighten.com.au

Luxeon M led above, others vary. Violets and UV faster than the above.. in general.
0.8 = 80%

And if poorly manuf may have the high intensity colors scorch their lenses.

Huh, maybe I should have read the article..

Once an LED chip has reached the minimum 6,000 required test hours for LM-80, a lifetime extrapolation, known as TM-21, is applied to the test data. TM-21 is the internationally recognised method for projecting lumen degradation of LEDs beyond the LM-80 test data.

Anyways it is impractical to test an led for 50000hrs soo a "guess"

As to spectrum, yea could be changes over time. See what I said about violets and high intensity blues.
Shifts may be noticeable but not technically detrimental to their function.
But like adding a brand new Gen4 (like new old stock or buying a lightly used used one) to a 10 yr 365/100% old gen 4 you probably will see a difference.

Just for fun..

To B50 or not to B50 – LED Maintenance Factors – INDO Lighting

indolighting.com

 

[Bpb]

Lots of good data here. I think the cliffs notes you can take away are “if you’re still getting the intensity you need, and all diodes are running appropriately (none burnt out), keep using it”. I support the whole drive-it-till-the-wheels-fall-off philosophy in life. Most people get new led fixtures years before they truly need to. Looking for that pot of gold at the end of the rainbow, I guess