[carolinyens]

So I've been looking a controllers and I took a program language class a decade ago so setting one up diy is out of the question. With that said I was wondering does anyone have experience with the apex par meter? I would rather get a reefkeeper since cheaper but I can't find one for that set up. I want to use for setting up for par readings, so I can know exact measurements as well as store data so I know when the light is losing power.

 

[jeffkrol]

So I've been looking a controllers and I took a program language class a decade ago so setting one up diy is out of the question. With that said I was wondering does anyone have experience with the apex par meter? I would rather get a reefkeeper since cheaper but I can't find one for that set up. I want to use for setting up for par readings, so I can know exact measurements as well as store data so I know when the light is losing power.

apex PAR meter uses the "old" Apogee sensor. not real good for LED's if that matters to you..
http://www.apogeeinstruments.com/content/SQ-500-spec-sheet.pdf

Nothing more than a V(out) photodiode..as far as output..

That said reefkeepers apparently has nothing..
https://reefbuilders.com/2015/07/10/top-5-reasons-apex-systems-pmk-par-measuring-kit/

Currently, besides some "3rd party" controllers, this function is pretty Apex only..
Seneye is one..
http://reefradiance.com/seneye-reef-par-meter.html

Seneye is about as accurate as the old Apogee sensor...

 

[Hoppy]

You will not be able to measure "exactly" what your PAR level is, for several reasons. The primary reason is that the PAR measurement is unique to one spot in the tank - each spot has a somewhat different PAR, since the PAR from a light varies with distance from the light, nearness of reflective surfaces, how clean the reflective surfaces are, distance from the center of linear bulbs, shade from leaves, etc. Even if those differences didn't exist, you would need a almost perfect PAR sensor, which the LiCor sensor is, and which the newest Apogee PAR sensors are.

If you just want to monitor the condition of the light bulb, reflector, ballast, etc. you can use almost any PAR sensor, and have a well defined location for the sensor to be placed, and measure at that location every week or so. Even though the PAR reading wouldn't be very accurate the changes in the reading should be plenty accurate.

 

[jeffkrol]

If you just want to monitor the condition of the light bulb, reflector, ballast, etc. you can use almost any PAR sensor, and have a well defined location for the sensor to be placed, and measure at that location every week or so. Even though the PAR reading wouldn't be very accurate the changes in the reading should be plenty accurate.

for that one can also just use a LUX meter...
https://www.adafruit.com/product/439


Just "pot" this one (or 3) ..

The sensor has a digital (i2c) interface. You can select one of three addresses so you can have up to three sensors on one board - each with a different i2c address. The built in ADC means you can use this with any microcontroller, even if it doesn't have analog inputs. The current draw is extremely low, so its great for low power data-logging systems. about 0.5mA when actively sensing, and less than 15 uA when in powerdown mode.

Of course, we wouldn't leave you with a datasheet and a "good luck!" - we wrote a detailed tutorial showing how to wire up the sensor, use it with an Arduino and example code that gets readings and calculates lux

 

[carolinyens]

Thanks for the help guys. I will continue to simmer a bit on this info.