Does LED PAR Really Drop Dramatically over the course of a Year?

[that Reef Guy]

I just read this Post.

"I was at a local, high end, fish store yesterday. Told the owner i was starting a new system. He asked me about lighting and i told him T5. His response was, "Good you're not falling for the LED scam". He went into detail about LEDS and how their PAR value decreases dramatically over the course of a year. I wasn't buying any equipment from him so i don't see why he would lie.

I purchased my first ATI fixture a few months back. The growth, overall health, and color on my SPS corals is amazing. I NEVER had success with sps before with my LEDS."

So does LED PAR Really Drop Dramatically over the course of a Year?

I have not heard that before.

I thought that LED kept the Same PAR for it's entire Life until they just Burned Out and had to be Replaced with a New LED Fixture which usually takes 50,000 Hours of Use or about 17 Years.

 

[rdevoe11]

good question...hopefully someone with more knowledge can comment on this...I can say, however, PAR values havent tailed off at all on my 160W razor over 3 months lol..I'll report back in 9 months

 

[stylaster]

As far as i know, leds dont dim out, if they are going out they just die and dont work anymore.

 

[ReeferBee]

There was a study done with a radion, maybe even on this site. It was a very small amount, something like 2% loss per year.

 

[rmcaum]

If you buy the t5s, you keep going back to the LFS for bulb replacement.

 

[cope413]

Saying that LEDs decrease in PAR dramatically over the course of a year is a virtually meaningless statement.

There are hundreds if not thousands of different kinds/brands/types of LEDs. There's nothing inherent in the technology that would suggest he's correct.

If he's implying that ALL LEDs intended for Aquariums decrease dramatically, then you should ask him for his data showing as much.

You won't find that data. PAR meters are cheap enough if you want to conduct an experiment yourself.

In general, I don't think LEDs maintain the same PAR for the entire life, but I believe that they maintain at least 80% for the rated hours of use.

It's likely he had a bad experience or has a personal beef with a vendor at the root of his negativity.

 

[NanaReefer]

If you buy the t5s, you keep going back to the LFS for bulb replacement.

Lol-exactly!!

 

[Pete polyp]

Sounds like typical lfs advice. I'm not saying every lfs in the world has no clue what they're talking about. I'm sure there are great people at some lfs that know their stuff. Ime more often than not lfs give the craziest advice. We are all lucky to have a place where we can go to research and weed through the bad advice so often given.

 

[Bad Company]

Typically the 50,000 hour life span on LEDs is the duration until they only produce 70% of their original light output. The statement that they lose a lot of PAR over the course of a year is laughable. 12 hours per day is only 4380 hours in a year, less than 10% of the time a decent led has until it drops to 70% output. LED PAR readings are also suspect because their output is such a narrow band that cheap meters don't read them correctly. Correctly cooled, LEDs last a very long time; longer than just about any other lighting technology, and more efficient too.

 

[Hypnotize]

There was a great study from a german guy who tested allmost all of the LED modules that are on the market. They lose about 10% in the first year and in the second year another 10% from the remaning 90% so 9% of the original 100% and so on.

That is a quiet large amount in my opinion.

 

[cope413]

It would be nice to post the study when you say something like that.

I don't believe the claim based on what I know about the technology, but if there is data supporting it, please share.

To reiterate: the usage hours on a light is the number of hours the mfg is guaranteeing the light will perform at or above a specific % of brand new lights.

For LEDs that's typically 70-80% and it's anywhere from 20,000-60,000 hours.

 

[ReeferBean]

If you buy the t5s, you keep going back to the LFS for bulb replacement.

Hehe indirect sales tactic ... although I also prefer my t5's after using LEDS for some time.

 

[Hypnotize]

It would be nice to post the study when you say something like that.

I don't believe the claim based on what I know about the technology, but if there is data supporting it, please share.

To reiterate: the usage hours on a light is the number of hours the mfg is guaranteeing the light will perform at or above a specific % of brand new lights.

For LEDs that's typically 70-80% and it's anywhere from 20,000-60,000 hours.

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[jedimasterben]

It would be nice to post the study when you say something like that.

I don't believe the claim based on what I know about the technology, but if there is data supporting it, please share.

To reiterate: the usage hours on a light is the number of hours the mfg is guaranteeing the light will perform at or above a specific % of brand new lights.

For LEDs that's typically 70-80% and it's anywhere from 20,000-60,000 hours.

All of this. LEDs are rated according to LM80 specifications for a set amount of hours at a set current below a certain temperature. Keep them cooler and they'll outlast their L ratings.


None of this is to say that there will not be manufacturing defects, or failures of fans, drivers, power supplies, etc, or that the builder of the fixture the LEDs are placed in was designed to keep them within specs, etc.

 

[cope413]

Mein Deutsch ist rostig but if I'm reading this correctly, he ran his lights for about 5100 hours/year and found that the LEDs lasted 6 times longer than the T5s. 48 months vs 8 months for the same PAR loss %.

It looks like he then estimates that the "real" life of the LEDs is 25,000-30,000 hours, not the 50,000 hours claimed by the manufacturers.

I don't know which specific models he tested, but that seems reasonable...

 

[TJ's Reef]

Another thing to add is that to all info/data I've read for this it was for running emitters at 100% or full potential. Some of the charts I've come across had varying table showing 1500ma/1050ma/700ma/350ma and there according life expectancy. As an example I only run my LED's at approximately 42% for 10.5 hours per circuit and roughly figured would be very good for around 11 years maybe longer ???
Maybe he just got his facts switched around and meant to say that LED's are the only lighting to not significantly lose PAR value over a year.

Cheers, Todd

 

[NanaReefer]

There was a great study from a german guy who tested allmost all of the LED modules that are on the market. They lose about 10% in the first year and in the second year another 10% from the remaning 90% so 9% of the original 100% and so on.

That is a quiet large amount in my opinion.

This is just hearsay without the documentation showing proof of the alleged study.

 

[shred5]

The led out put does go down over time, but it really depends on allot of things on how much and how fast.. If the leds are over driven they go down faster.. If they have less cooling they go down faster.. If like allot of the Chinese fixtures and they use those thin heat sinks they drop faster ,the closer the leds are together etc.... Heat sink is the single most important thing in a led fixture and one of the most costly... All those things can shorten the life expectancy..

But because of so many different thing affect the output it really is hard to test because it can very from fixture to fixture... I do remember seeing one study though, wish I could find it but it was a larger drop the first year but after that it is minimal... This study was done in lumens but par drop would be about the same since lumens is the measure of light output. My guess is at the end of the leds cycle it will drop very fast..

I have heard a few people notice a difference that have add a new fixture next to a existing fixture of the same type and they can see a output difference and some have noted a spectral difference too...

Now I don't think it is anything to wory about and a led fixture should be good for at least 5 years or more if it is a decent one. It would be cool if people did measure the output every couple of months for a while to really see.. I will look tomorrow and see if I can contact a lighting rep and see if they have any studies. They would be in lumens or footcandles but a drop in light put affect a drop in par probalby exatly the same.. Finiding a study on par would be tough..

If you buy the t5s, you keep going back to the LFS for bulb replacement.

Really why does someone always have to turn these into a t-5 vs led vs halide debate.. That has nothing to do with the drop in par of leds and adds nothing to the discussion.

 

[jedimasterben]

Really why does someone always have to turn these into a t-5 vs led vs halide debate.. That has nothing to do with the drop in par of leds and adds nothing to the discussion.

Because that is why the LFS in the OP wanted to discourage that person away from buying LEDs, as they would presumably no longer be purchasing bulbs from their store.

 

[lefkonj]

I have only seen LED lights (not aquarium related style) dim as they have issues, like cooling or death. It happens. The reality is that LED lights have proven to provide the same PAR over the course of years worth of use. When compared to T5s you would replace a LED for everyone 5-8 T5 bulbs.