Is the apogee SQ-120 accurate with LEDs?

[drawman]

I just rigged up my apogee SQ-120 and have it wired to a multimeter. I'm multiplying these readings by 5 and by 1.08. I'm curious how accurate this measurement is with Radion LEDs. I'm assuming it's good enough for a ballpark just don't want to start blasting my acros too hard.

 

[jda]

All PAR meters are just ballpark. They oversample some spectrum, under sample others and forsake some all together.

Just use it as a swag and to get hot and cold parts of your tank and you are all set. Counting on it as an absolute is probably a bad idea.

 

[LARedstickreefer]

I’ve got one. I have my Acros in the “350” range and none are burning up

Edit: I’m using the Reefi Led Extreme.

 

[EMeyer]

Apogee provides some really great, detailed info on correction factors:

How to Correct for Spectral Errors of Popular Light Sources

Spectral graphs and correction factors for 36 popular light sources and instruction to correct for errors. Apogee quantum sensors help you get the most accurate PAR measurements.

www.apogeeinstruments.com

I think these get us much closer to true PAR measurements. I end up using ~6 for blue LED channel and ~5 for white LED channel, then adding then together to calculate total actual PAR.

 

[drawman]

I'll be aiming to get acros to about 220 PAR to start. I figure that will be a happy medium so I can see how things respond and increase/decrease as needed.