PAR values under my DIY LED

I borrowed a PAR meter to measure the actual brightness under my DIY LED.


As you can see, its way less than I thought! Im always told that I need to dim my light..

RB: 100%, CW: 33%, NW: 27.5% (odd number since the module runs 11V max) Colors:700mA..

Hmmm..

 

Seems to be working for you tho. I also achieve about this much par under 2 ais set at roughly 40% total output.

 

Thanks for your input, skurious!

 

What kind of Par meter are you using?

 

This kind..


I thought about you when i was Photoshopping the pic! lol

 

lol, ive read apogee meters reads lower with leds then other types of lights not sure how much thiugh. and also do you kmow what brand that is electric or sun type of meter, also i have the same sensir and get accurate readings when the meter is directly vertical with the light

 

just read this up, they have a taable of recalibrating the numbers

Aquarium Par Meters - Apogee Instruments

hopes this helps

 

i tried to face the sensor as straight up/vertical as possible. Thanks for the recalibrate table!! So the meter could be reading ~10% less! I feel kinda relieved!

 

I've read that the par meters usually read LED lower, primarily the blue leds. YOu have your Royal blues at 100% so if thats the case then your par is probably quite a bit higher than what the meter is showing. I cant remember what number I read, but I swear it was over 10%, and closer to 30%.

 

This is a myth perpetuated by Apogee, probably because they are a company that has absolutely no experience with reef aquariums. I have discussed the issue with them and their comparisons are based on a 5500K metal halide (because of course that is what all of us are using : ).

The the more blue you go, the more the apogee will underestimate, this is regardless of lighting type. A lot of halides actually have more deeper blue than a lot of LEDs though, as royal blue does not go much below 450nm for example and a lot of halides have spikes around 420. Also, LEDs don't have tons of red, some halides do and the Apogee also underestimates red, not just blue. So, in many cases you could actually find that the halide is more underestimated.

As to the PAR numbers, it depends more on optics and total system wattage, which you don't display. Technically, halides should still output more total visible light (PAR x area), but may not focus as well (visible light / area=PAR). So, if your using wide optics, or significantly less wattage than an halide necessary to cover the tank, you could get less PAR for sure. Mostly the reason to run LEDs at lower PAR, in my experience, is to acclimate corals to the change in spectral characteristics. We used to do the same with halides when switching from say a 10K to a 20K, it could take a long time for corals to adapt. However, they can adapt, in my Fluval edge, I have zoanthids, Ricordia, other mushroom corals , leathers etc... Under over 400-600PAR (per Apogee meter) of LED lighting, for IIRC nearly 2 years and they seem to love it....