PAR Meter Thread

Well .. I got my PAR meter today. I have not gotten a chance to play much yet, but I wanted to start a thread about it for the people who are interested in it and/or having me stop by to measure their bulbs.

If you do want me to come over and measure your bulbs I would be more than happy to! I would love if you gave me a 5$ or 10$ donation (or whatever). I will take this $$$ and put it into a pool until there is enough to order another PAR meter to just pass around the club. Don't feel like you HAVE to give anything though. Its my pleasure just to come look at your tanks!!!

I'm still figuring all this out and I have a couple of questions, but here is the info I have gathered so far. I TOOK most of this directly from post on RC.

The meter I have is a Apogee Instruments QMSS-ELEC Quantum meter with sensor. Calibrated for electric lamps.

First, what's a PAR meter

A PAR meter measures light intensity. For example, in the sun the meter read about 1600 PAR, while the 250 watt bulb over the clams measures about 350 right above the water. This meter is calibrated for electric lamps. There is a conversion to use, I think based on bulb Kelvin rating, because the light frequency affects the measurement.

A PAR meter can be used to compare lighting systems, see the impact of an upgrade, etc. It can also be used to detect degradation in your bulbs, based on a change in intensity. Again, if anyone has specific information about that, feel free to post.

The instructions are included, and it is VERY easy to use.

What should I do with it?
Get measurements from anywhere in your tank ... from one spot, or many different spots. The probe is water proof and the sensor is fully submergible. In fact you will get a much better idea of how much light you are providing to your corals by taking in tank measurements. Water clarity plays a huge role in the amount of light reaching your animals, as such you can find large differences from one tank to another even when using the same lighting.

As time goes on, that we can give light requirements of certain corals in terms of PAR rather than high, medium or low light. It really helps other to understand what lighting you have a coral under when you can tell them the coral is under an Ushio bulb receiving 380 PAR.

By the way, the light sensor is attached to the meter with a cord. You can hold the probe over the water, and the meter NOT over the water, so the meter won't get dropped it.

from apogee:

As you can see from the website, the Apogee sensor does have an imperfect spectral response. This is due to the difficulties of getting silicon to absorb the entire range of visible radiation. As a result, we calibrate our sensors to specific light sources to correct for the spectral variation. This works very well for plant researcher's who use a limited number of light types in their greenhouses.

Given the number of lights available in the aquarium industry we can not possible go through and calculate the correction factor for each of the different lamps. However, Joe Burger is also interested in quantifying aquarium lighting, wanted to get correction factors and we have supported his studies. You can find his results and correction factors on the web at http://www.cnidarianreef.com/lamps.cfm.



AGAIN
Great site with bulb and PAR info. http://www.cnidarianreef.com/lamps.cfm

My first Q ... Joe Burgers website is very clear, but how does this relate to sanjays bulb data? He (sanjay) doesn't list a straight PAR value.

Ok I know Shane is first on the list for a visit and I will bring it with me to Jeff and Brads on Friday. Anyone else?

Man that was a long post with lots of opprotunity for spelling errors... Yes  I did that one on purpose.

I would also appreciate a visit for the reading as well as your opinions on lighting improvements.  I am running pc only and am ready to make improvements.  I am in WVC near Dkle.  Willing to contribute as well!