Complete PAR survey of my Tank

This is very helpful, I can't wait to look at it a little closer when I have some time. I have the same 2 lights, and have been very apprehensive about settings and timing. After I finish my new and improved water changing station/system (hopefully today, finally!!) getting my lighting dialed in is next on the agenda. Thanks for all the effort!

 

Glad you like it - if you have any questions about what I found or any of the measurements, don't hesitate to ask.

 

I was told that PAR is inaccurate with Led is this true?

 

I don't know for sure, but I have done some research on this, and nc208082 provide a link a few posts back on this subject.
Light Intensity Measurements for Light Emitting Diodes (LEDs); Correcting for errors

basically, the way I understand it is that the PAR sensors tend to have less sensitivity toward the blue spectrum. LEDs tend to put out more blue, which introduces a margin or percentage of error in the readings.

The PAR numbers may not be 100% accurate when used to measure LED output, but I think they provide at least a guideline as to where the most and least usable light, as it relates to photosynthesis, is being shed.

The main thing I noticed while I was taking the measurements, and you can kind of see this in the results, is the optics/lenses play a big role in how the light is distributed. Not just in the spread, but also in the contrast - particular in the shadow areas.

There was very little ambient light generated. So you end up with areas of very low light, right next to areas with high PAR readings. an example of this was in the D2 and N2 locations on my map. These where areas that where in shadow, but just a 1/4 inch out from the rock where pushing 3-4 times more PAR.