PAR readings

[kamloops_reefer]

Looking for opinions on PAR readings - I just tried out our Seneye device that we've had for over a year (only used for a month). When I place the sensor just above the water (about 10" from light source) I'm pulling about 160 PAR on a relatively large DIY led build.

This seems low? Am I mistaken that I should be getting 300-600 PAR at the high points in my tank (in water)?

To compare, I tested the sensor against another LED light I have at a similar distance, and a dual bulb 48" T5 HO fixture at approximately 12" below (not in water) and they were 160-170 PAR

[ReefMadness]

if i remember correctly the seneye par meter will give accurate measurements of T5 and Halide fixtures but is not very good at picking up led. someone feel free to chime in if you can explain why.

[iamfrontosa]

^ i read that somewhere also.

[Scythanith]

LED readings are usually only about 5-10% off in my experience. Each colour spectrum is different. You can find the articles and proper calculations to adjust an apogee sensor on their website. Not sure about the Seneye though.

I'd say 160 is quite low on the water surface. I get anywhere from 450-800+ at water's surface with Mitras and T5's (about the same height as you).

[Frogger]

Apogee makes a led par meter, although Bulk Reef Supply tested it and said it was calibrated improperly. They may have fixed that poor calibration.

[dcw1sfu]

This may interest you guys. It was a comparison done on the Seneye and Apogee par meters. They were very close for the most part.

http://www.reefcentral.com/forums/sh....php?t=2626700


Also a BRS TV video comparing the Par Meters:

https://youtu.be/6hUkufXBb3I