LED degradation over time

Hey Everyone,

Last time I created a thread, there was no LED lighting section !

Anyway,when I first switched over to LED, my tank was still in it's infancy.I thought 4 par30's would be enough.Then I wanted to explore SPS and realized I'd need more.So I went the DIY route and added some from RapidLED,like many others here. Almost two years later I've made some interesting observations.

One of the par30's died about 5 months ago.It was still covered under warranty and was replaced hassle free.After receiving the replacement I immediately noticed that it's output seemed to be brighter than the other 3 that were from my original order. I noticed all the cool white's on my original par30's have a burnt look to them(when OFF).There are actually brownish stains embedded in the lenses/or LED itself,though I'm not 100% sure which it is. Once powered they still work fine.

As for the on-stars: I just added some more on-star LED's this past weekend and changed some of their orientation. I swapped all but one of my RB's for the newer XT-E RB's.The newer LED's are brighter. I was under the impression that the XT-E's were only more efficient,not brighter than previous versions. Maybe that observation is bust because the old and new aren't the same model. I also added another XP-G R5 to my CW string with the same exact lens as the others.This newer LED is very noticeably brighter than the older one's! All of my on-star LED's are wired in series.All those of like color are powered by the same driver.I'm also using constant current drivers,not dimmable. The difference in time between the old and new is no more than 8 months. I know LED's don't like heat and part of their performance and longevity can be attributed to temperature.That being said,while my on-stars are mounted on heatsinks,I have no fans in the canopy.In my defense on that matter,my tank is in a basement where ambient temps in the summer are no higher than 75F in the summer and 60F in the winter(I run 700W worth of heaters). I'm considering the addition of fans.

This long winded post is just an inquiry as to weather anyone else here has noticed anything similar. Looking for some of the veteran LED users to reply ie.,Evolved ;D

 

I can't say for led fishtank lighting, but for the servers in my server room, you can easily tell the time frame in which each server was bought just by looking at the front leds. The dimmest is the oldest. They definitely dim quickly. Its the main reason I refuse to go led until prices come down a bit more. I'd sure like to see more real world positive experience with the aquarium leds.

 

Bump...

 

Yeah, I saw this yesterday...

I don't have a whole lot to say, but these were the two thoughts I had:

Heat is the enemy of all things electronic. Improper cooling surely could have an impact here.

Also bear in mind buying a batch at a different point in time may yield diodes of a different group/bin. This would cause them to look differently as well.

 

+1 Exactly.

I've seen LEDs dim and fail rather quickly in other applications as well, and I refuse to switch until I see long-term success with the technology.

 

I think it may be related in part to your heat issues. I had a similiar experience with mine which was heat related and has the exact same effect. If the heatsinks build up too much heat the leds become dimmer due to this as well as the led can brown out on the lense and diode. My fans malfunctioned and one of my heatsinks fried itself. a couple of my leds that still worked from that heatsink were noticeably dimmer than the rest, as well as having the same brown coating. Remember when DIY there is a lot of trial and error.

 

I have 4 boost led lamps with 5 leds per lamp. I have had them a year now. I got them from Boost Led's. My soft corals and mushroom corals, zoas etc. thrive on them and so far I have lost none. For details look them up on the Boost site. Just my experience, hope it helps. They are also guaranteed for 5 years and since they are the smaller lamps with many slats for air, I have had no heat issues. They have not dimmed a bit yet. Again, I hope this helps! I really liked the Boost Led guy. He answers questions personally and is a small American business, and I can support that! Also, a guy who used to post on here all the time, (omar something) who I reallly respected in this hobby,changed all his lighting to led's and they use his tanks as a models on their site. I can say it sure made a difference in my electric bill anyway! Good luck!

 

LEDs if properly cooled should probably loose somewhere around 5% of their output per year. If not properly cooled, could loose a lot more. I think one risk with PAR bulbs is that they don't have any cooling fan, so, i they are stuck in a canopy or something, where there isn't good airflow, they could degrade faster. An external fan though, or something else, to help keep them cool, isn't a bad idea and would definitely provide some insurance. As far as dimmable LEDs, it's always a good idea to go bigger and more powerful than needed, so that you can increase the output over time, as they dim.

 

Thanks for the replies everyone. So fans are definitely in my canopies immediate future . What's the best way to configure with my Apex? Have another temp. probe and have them come on at a certain temp. Or just have them come on at timed intervals?

 

5 years? As far As I knew the lamps only carry a one year warranty.