PAR additive or not

[dinosaur_1552]

Does anyone know how PAR should be estimated with multiple light bars.

Lets say one light bar gives me 200 PAR at a given depth in an area below it, will two light bars close to each other will give 400 PAR in their common "intersection area", is it additive or not?

 

[Dan_P]

Does anyone know how PAR should be estimated with multiple light bars.

Lets say one light bar gives me 200 PAR at a given depth in an area below it, will two light bars close to each other will give 400 PAR in their common "intersection area", is it additive or not?

Yes, it is additive, but human perception might not perceive it that way.

 

[rgulrich]

Yes, it is additive, but not in a "1+1=2" way; use a PAR meter to confirm your PAR levels.
Cheers,
Ray

 

[dinosaur_1552]

Yo, just an update, as per my tank thread in the end I got a budget PAR meter and tested things around.

I also tested with two lights and a par meter below them.

Light 1: ~230 PAR separately
Light 2: ~340 PAR separately

Light 1+2: ~560 PAR

So it seems to be almost 1+1 additive, at least with this PAR meter and this simple test.