# par metre not mesuring 10 wat led chips



## scott tang (Jan 29, 2012)

so i borowed a par metre off a friend and it doesnt seem to be mesuring corectly at 100% power to the fixture 5 10 wat chips 3 blue 2 white x 2 pendants the par in the tank on the botom says 20 now that inposible as i can bleach corals at 70% any one have and advice here ? 

i mesured my ever grow fixture and redings were acurate so its not the metre 

the only thing i can think of is the fuxture not being full spec and there for not mesuring proporly ? 
i only have one kind of white led and one kind of blue led in it but it seems to grow corals well


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## SeaHorse_Fanatic (Apr 22, 2010)

PAR meters unfortunately are not what should be used for measuring LED lights. It should be PUR (Photosynthetically Usable Radiation) meter is what you need for LEDs. Unfortunately, while a PAR meter is only 2 or 3 hundred, a PUR meter is ridiculously expensive and nobody I know has one.

I've tried to borrow a PUR meter but couldn't find one anywhere. Maybe a specialized laboratory working on lights would have one.

Here's a link:

PUR vs PAR in Aquarium Lighting (LED); Spectrographs


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