Par readings on our Coral Maxx LEDs

I've been told just the opposite by most hobbyists I've asked.

Yes, I was wondering if it was true, because when I cited this people immediatle posted this was not true
This may be true for 1w LEDs like this, perhaps not with Cree and other dimmable LEDs.

 

These are 2 watt led's. During the design of these lights the manufacturer advised us the dimmables would potentially cut the life shorter.

 

The biggest enemy to a LED diode is heat. It does not matter what the wattage of the diode. If you take a 3 watt LED and run it at 1.5 watts it will last much longer than the same diode running at 3 watts. Dimming a LED can only extend it's life.

 

Oh, 2w diodes. Who are they made by? Perhaps it is because more are run on one circuit, so fluctuations in power might damage them?

 

This was the rationale that I was given. Perhaps it would only change lifespan if they were constantly being switched between 3w-1.5w every couple seconds?

 

Exactly. The only thing I've come across is a claim that constantly changing the wattage (sunrise/sunset all day) can hurt the lifespan.

 

Same as I have heard.

 

All I can say it completely goes against everything we know against LED unless the LED's are being driven to a temperature that exceeds their max specs.

 

PAR is such a limited and misleading measurement, however. One could have a fixture that is incredibly high PAR but completely lack the PUR output for marine invertebrates and it wouldn't grow coral at all!

It isn't the action of dimming that shortens the lifespan of the fixture, it is the inferior quality of the dimming electronics. Emitters can last for decades, the electronics required to drive them often have a much shorter lifespan.

 

However, PAR is the easiest and most effective way to compare LEDs until someone finds a better way. Every manyfacturer has a different measurement but for right now I think PAR is the best way to compare LEDs to LEDs.