New Apogee PQ-510 Microcache (SQ-500-SS2 full spectrum probe)and PAR readings

Smarkow · Jul 13, 2020

Hi all, just purchased the apogee bluetooth logger and their classic probe. Nice package and price point IMO.

I have a 210 display with two kessil AP700s with 4x 60 inch Coral Plus T5s. The kessils max at 75% with the Ocean Blue 3. The lights are in an aqualife hybrid fixture.

So I do have some questions re the Apogee units and conversion to PAR. It looks like the Watt/m^2 default units are all the SQ-500 measures (and obviously does so in full spectrum). So converting this to PAR is something I have not quite figured out. If anyone wants to help me I’d appreciate it.

Here is one section of my tank and the associate apogee spot measurements.

Data points above and their exact values below/right.

I am curious re others perspectives. Will take some more measures tomorrow!

Thanks all

Smarkow · Jul 14, 2020

Self bump

Lol wondering if anyone can help me on the conversion of Watt/m^2 to PAR

oreo54 · Jul 14, 2020

Some researchers use the approximation 1 W/m2 ≈ 4.6 μmole.m2/s. First of all, μmole.m2/s is definitely an SI unit. The approximation 1 W/m2 ≈ 4.6 μmole.m2/s comes from the Plant Growth Chamber Handbook (chapter 1, radiation; https://www.controlledenvironments.org/wp-content/uploads/sites/6/2017/06/Ch01.pdf). Note that the value of 4.57 converts Watts/m2 to μmole.m2/s, assuming that the W/m2 is for radiation from 400 to 700 nm.

Surprised you can't switch units in the software.

WHICH sensor do you have?

piranhaman00 · Jul 14, 2020

They aren’t really convertible units, you must be able to change units in the settings

Smarkow · Jul 14, 2020

piranhaman00 said:
They aren’t really convertible units, you must be able to change units in the settings

You would think!? I haven’t had a whole afternoon to work with it yet, but it’s not that complex of an app... Sort of flummoxed that I can’t figure it out