PAR Rating overlaps

[RyuMcDohl]

So I would like to pose a question out there that has had me wondering. When it comes to light and general par rating charts at the various levels in the tank and left to right area they take up. If we experience overlap of two lights where say light #1 gives you a 200 par there and the overlap light #2 gives 400 par in that same spot do we add, average, or take the highest of the two values in this scenario. At first my thought was that the two numbers would be averaged, but then after over thinking it I was not sure. Because if 200 and 200 overlap you are giving that area more light from two sources so it makes me think they should be added and not averaged . Thoughts everyone ?

 

[ksc]

You would add the par numbers.

 

[Ron Reefman]

I have a PAR meter so I've done the test. The 2 get added together and then use about 90% of the total.

 

[RyuMcDohl]

Awesome that is kind of what I figured it might be Ron an addition type calculation but then knock some percentages off

Got the first of the three reef breeder lights today. And they look pretty slick wanted to swap it to my small nano existing tank until things are ready to move, but it's dimensions are a tad bigger then the nano so might have to improvise

 

[ksc]

There would be no need to subtract 10%. Depending on what meter you are using you would add 7-30% if you are taking your reading under water. Also some meters don't read the blue/violet spectrum that well.