My take on Neptune Systems' PMK (Par Monitoring Kit) Module

by Richard Back 

During Q4 of 2015, Neptune Systems released a new module called PMK (Par Monitoring Kit) module for your apex.
Recently I had gotten my hands on one because I wanted to keep an eye out on my par during my ramp up times to peak and to my ramp down times to eliminate the guessing work on placement of some of the light sensitive corals. Yes, too much lights can kill your corals as much as low light to no light can kill corals as well.

So here we go! Let's unbox this thing!

​First thing that I noticed was the sensor.

From the first glance, it looks like the high quality original quantum sensor from apogee which is well trusted brand and go to unit for both hobbyists and industry professionals looking to find out their PAR level from their light fixtures.  It looks similar but is it the same thing? No, it's not. It may feel different because it's made out of different material. This sensor is made to be continually submerged while the standard apogee is aluminum with powder coating and it will come off and pollute your tank if we tried to use it in same application. (in house tests were done in Neptune Systems to confirm this) 

I really like the hidden enclosure that it comes with. Custom made from Real Reef Rock company, it hides the unit extremely well and places the cord in place so I can easily bury the excess wire under the sand to conceal it. 
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Time to check out the unit! 

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Unit was placed on my sandbed where I like to put my LPS (Euphyllias, Chalices, Platygyras, Favias etc) and softies (Florida Ricordias, Mushrooms and Rock Flower Anemones)  I have my Ecotech Radions Gen 3 Pros programed to come on during 12:30pm, ramp up and peak about 2pm and maintain until 6pm then slowly ramping down until 8pm which then kicks into full actinics until lights go out.  

You can see from the graph above that the PAR peaked at 102 on my sandbed. Average of the day including the ramp up and down time  was 83.87 and the minimum was at 48 PAR.  Why is that important? I spoke with Terence Fugazzi of Neptune Systems and I think he nailed when he said because it's not always about adding more PAR to the tank or checking during the peak hours. We have to know during the majority of the hours the animals are exposed to know if we are not starving the corals of the lights that they need to thrive. As long as spectrum of the light source is constant, you can understand the relationship in your tank between % intensity and PAR with this unit. 

I read this article about immersion on Reef Builders! Is this unit accurate? 

For those of you guys who haven't read it, immersion effect is caused when a quantum sensor that was calibrated in air is used to make underwater measurements. Sensor will give lower reading. This is fixed by multiplying the PAR reading by 1.08 (this unit is original quantum sensor) For example, my peak PAR is 102. To get accurate underwater reading, we would multiply 102 by 1.08 which will equal to 110.16 PAR.  So accuracy is definitely there.

You can find out more information about immersion effect here on Apogee's website. 

Terence has told me that sensors themselves does not need any adjustments for the update that the apogee recently did with their units so I'm thinking that it is possible that simple AOS firmware update can maybe incorporate it down the road. 

I hope you guys liked my hands on review of PMK unit and think about maybe adding it to your arsenal of cool modules from Neptune Systems on your Apex unit. For me, I will be adjusting my lights so that it goes up to close to 150 PAR on sandbed. 

Check out the video here as well!