Apogee USB Smart Quantum SQ-420 PAR Sensor vs SQ-120 With Volt Meter

William Morris · Feb 27, 2021

Interested in opinions and experiences with the SQ420 and the SQ-120.
I know there are some limitations to reading the blue spectrum with LED's and I run LED's in my Biocube 32.
My interest was sparked after watching this video with a DIY hack using the SQ-120.
The conclusion from the video was the SQ-120 is pretty darn accurate compared to the more expensive MQ-510.

The SQ420 uses a USB connection to send the readings to software on a computer.

Anyone have a hack for the wand that Apogee sells for $70?

P-Dub · Mar 3, 2021

William Morris said:
Interested in opinions and experiences with the SQ420 and the SQ-120.
I know there are some limitations to reading the blue spectrum with LED's and I run LED's in my Biocube 32.
My interest was sparked after watching this video with a DIY hack using the SQ-120.
The conclusion from the video was the SQ-120 is pretty darn accurate compared to the more expensive MQ-510.

The SQ420 uses a USB connection to send the readings to software on a computer.

Anyone have a hack for the wand that Apogee sells for $70?

Yup, pretty close and likely close enough for most of us. I just used a clear, thick-walled acrylic tube, and melted a bend and flattened it at the end, and drilled a hole to mount thesensor for my wand.

William Morris · Mar 3, 2021

P-Dub said:
Yup, pretty close and likely close enough for most of us. I just used a clear, thick-walled acrylic tube, and melted a bend and flattened it at the end, and drilled a hole to mount thesensor for my wand.

Can you post a photo of your wand? Are you using the SQ-120?

RayDRoot · Mar 3, 2021

I used the thin half of a fishing pole to mount my 420, lol.

jeffp1 · May 10, 2021

I used a 1/2 inch piece of pvc pipe with a 45 degree coupling on the end to mount the 120. Cut a small slot in 45 to fit the screw on the 120.

Aardvark1134 · May 10, 2021

Here is the difference blue line vs black line...with standard reef lights will be close...with something like the orphek or3 UV bar which is 410 420 and 430nm the difference between these 2 meters will be huge.