DIY Par Meter Question

[jisherwood]

Ok I followed willthethrill post and finally got everything put together but when I test I get low PAR readings.
Tank info:
75gal reef w/ 20gal refugium
2 kessil a360w
Apex controller.
Purchased used Apogee SQ-120, its a few years old. Do I need to send into Apogee to get it recalibrated?

 

[mcarroll]

You should tag anyone you know of that's made one of these. (I can't remember off-hand.)

 

[jisherwood]

OK im new to this so how do I tag folks

 

[saltyfilmfolks]

Did you do a side by side in the sun with both meters?

 

[mcarroll]

@ + their username.

Like this...

Thanks for asking that insightful question @saltyfilmfolks!

:)

 

[Fritzhamer]

Following along. I was looking to do this today. Wasn't sure if I needed the SQ 520 for LEDs or if the SQ 120 could cut it with some kind of adjustment.

 

[mcarroll]

Depends what your goals are for the data IMO.

• Many of us are fine with the output of a standard lux meter. (myself and salty among them)
• A basic PAR meter is already "better" than our lux meters, depending on your needs.
• The 5xx-series is "better-yet". Needs.

You get the picture. ;)

 

[saltyfilmfolks]

Following along. I was looking to do this today. Wasn't sure if I needed the SQ 520 for LEDs or if the SQ 120 could cut it with some kind of adjustment.

There is a slight difference yes. But imo after several years of debate over immersion factors, led vs mh etc. discussions with pro growers light manufacturers etc as long as you have a general base line of your par you really are probably ok to use it.

Just understand that you may be off slightly. And the amount is likely to only be 75 par or so.

Think of the constant accuracy vs precision discussions with any test kit we use.
Same thing.

 

[saltyfilmfolks]

Depends what your goals are for the data IMO.

• Many of us are fine with the output of a standard lux meter. (myself and salty among them)
• A basic PAR meter is already "better" than our lux meters, depending on your needs.
• The 5xx-series is "better-yet". Needs.

You get the picture. ;)

Hahah. Yup.

 

[jisherwood]

@willthethrill Also Kessils are siting 10" of water

 

[Emery]

I just received a SQ-110 model that is sun calibrated. The Apogee rep told me they found the sun calibrated model to have more accuracy. I believe he told me the 110 model is +/- 5% where the 120 model is +/- 10%.

Either way, is send it in for calibration and give the Apogee team a call. They're very helpful and will walk you they the corrective math that you need to do to get the exact Par readings depending on your sensor and light source.