The PAR Monitoring Kit recently announced by Neptune Systems is a very intriguing new accessory that could unlock the door to learning oh so much about our aquariums. We were very thrilled to see the release of the BioTek Marine PAR Sensor which plugs into any computer using just USB. However without the smarts to monitor and log lighting levels over the long term, for now the BioTek USB PAR sensor is just a more affordable way to get point sources of lighting levels.
By contrast, the PAR Monitoring Kit is a real breakthrough in ways that Neptune Systems hasn’t even really thought of. So without further ado, here are the top five reasons to use the PMK to learn more about lighting on your reef tank.
#5 getting a feel for the rate of algae growth – We’re all thinking it, but Neptune Systems is not going to point out how algae growth on the sensor itself will significantly affect the accuracy of the PAR readings from their sensor. We all know this is an issue, so just make sure to keep the sensor clean as often as possible and use this phenomenon as an opportunity.
After running the PMK for a while, you will get a feel for how much the PAR readings are impacted by algae growing on the surface. Throughout a period of a week or two, you should be able to see the dip in PAR value that corresponds to a rate of algae growth.
If algae builds up on the sensor faster than usual, that will be a good sign that perhaps you’re due for a water change, refreshing the GFO or what not. On the other hand, if algae grows on the sensor is slower than usual, you can probably assume that your tank’s nutrients are well in check and just keep doing what you’re doing.
#4 Lights are staying on or off – We love it when technology works, but it’s always good to have some failsafes to prevent unintended settings, and especially to mitigate operator error. We are guilty, on more than one occasion, of manually turning on the lights on the reef tank using the Apex, and then forgetting to reset the lighting setting back to automatic, causing the lights to stay on.
With the PMK users will be able to automatically have the Apex know that your lights really should be off at three oclock in the morning. You can get alerts that your lights are staying on, or that they are not coming on, and depending on the placement of your PMK sensor you can might be able to register lighting intensity of the room lights should someone leave the room lights on.
#3 Changes in light performance – Lighting hardware is not magic, it’s a kind of light engine. Like all machines, artificial lighting does wear out over time, and different technical issues can have a great impact on the performance of your lighting source, regardless of the type.
Metal halide lamps wear out a little bit every time they are fired. The phosphors & electrodes of fluorescent T5, VHO and power compact lamps also wears out and shows a dimming of the light output and quality over time.
Even LEDs dim over time, and this can be exacerbated by less than ideal operating conditions. Heat-venting fans clog over time, and if they fail they can cause LEDs to overheat which will translate into an immediate but temporary reduction in lighting output. If you can catch an irregular dimming of your LEDs due to an overheating issue, you might be able to rectify the problem before longterm overheating leads to permanent damage to your diodes.
#2 comparing PAR from different led color channels – Reefers who have been learning about, measuring, and applying PAR for understanding the lighting requirements over our reef tanks have an almost innate ability to estimate it, within about 10-20% accuracy. This applies strictly to broad spectrum lighting and once you start playing with the lighting source’s EQ levels, all bets are off.
With the multicolor and multichannel control now available with LED lights, we can now mix and match the rainbow of color over our tanks with incredible precision and selectivity. However, none of us are well versed in how the broad PAR value is affected by different wavelengths of monochromatic light. Because they are designed for taking the average intensity of broad spectrum light, we know we can fool PAR meters into giving very high light levels. However, we can’t fool our corals into thinking the actual PAR is this or that level.
In conjunction with the PMK we can now begin to experiment with giving our corals specific doses of specific lighting wavelengths and seeing what happens. Sure you can already run different LEDs at specific intensities, but what happens to a coral when you give it 50 umols/m²/s of deep red light versus the same PAR of green light, or cool white LED light? With the PMK we can begin to unravel some of these questions, and really make some headway into how our corals react to different light levels.
#1 Measuring total PAR of the photoperiod – With reef aquarium lights getting more and more sophisticated everyday, we have more granular control over so many aspects of lighting color, intensity and duration. Currently, reefers only talk about their lighting levels in terms of peak PAR value, but hardly one in ten reef aquarists can even name the unit for PAR.
PAR stands for photosynthetically active radiation, and it is measured in umols/m²/s, pronounced as “micromoles per meter squared per second”, or micromoles for short. A “mole” of something is a scientific unit, also known as Avogadro’s number, and it is equal to 6.0221415×1023. We don’t need to explain what this really means for us to really get to our point.
Since PAR is a measure of a number, per surface area, per time, if we monitor PAR levels all throughout the day, we can actually normalize our PAR values to umols/m²/day. This is a brand new, very valuable metric for reefkeepers because now instead of clumsily explaining to someone our photoperiod, the colors that come on and off, and how the PAR value changes throughout the day, we’ll be able to quickly communicate the total amount of PAR a certain coral is getting throughout an entire day!
For us, calculating PAR in moles per day is the real breakthrough of being able to measure and quantify lighting intensity that our corals get using the Par Monitoring Kit. We’re not sure if this concept has even occurred to Neptune Systems, but surely a little bit of programming magic will unlock the measurement and calculation of daily micromole exposure that our corals get. And once we have this value we’ll really begin to understand the complete lighting needs of so many different photosynthetic aquarium animals. [Neptune Systems]