PAR vs PUR

acesfull44

Valuable Member
View Badges
Joined
Jan 21, 2015
Messages
1,581
Reaction score
3,225
Location
St. Louis
Rating - 100%
1   0   0
I am curious to get some feedback if the difference between PAR vs PUR. Specifically if this is an issue that I need to address so I can gain thr most growth, color and health for my corals.

I am currently running 3 of the Red Sea 160s LEDs over my 310 Planet. I have recently rented a PAR meter and directly under the fixture (hangs 12" off the water) at the top of the tallest rock the reading was 185. I have a TGC Inferno Colony right in that spot that seems to be doing just fine.

The question is how do I relate the PAR reading since based on the Red Sea website and the design of their light which focuses on PUR?

Any help on this matter is appreciated. Thanks.
 

oreo54

5000 Club Member
View Badges
Joined
Sep 18, 2017
Messages
5,532
Reaction score
3,411
Rating - 0%
0   0   0
I am curious to get some feedback if the difference between PAR vs PUR. Specifically if this is an issue that I need to address so I can gain thr most growth, color and health for my corals.

I am currently running 3 of the Red Sea 160s LEDs over my 310 Planet. I have recently rented a PAR meter and directly under the fixture (hangs 12" off the water) at the top of the tallest rock the reading was 185. I have a TGC Inferno Colony right in that spot that seems to be doing just fine.

The question is how do I relate the PAR reading since based on the Red Sea website and the design of their light which focuses on PUR?

Any help on this matter is appreciated. Thanks.
Unless you are running green- yellow lights chances your par is " relatively" close to pur. Well around a 20-30% difference mainly based on the fact few would run an oddball spectrum with mostly lower put par nm.
300 par is 240 pur.
Since most in line measurements do not adjust readings for pur and usually run pur rich blue heavy spectrums.. pretty hard to be concerned with it.
PUR is a moving target in a sense.
More than likely changes a bit by err " species" anyways

PAR is an artificial construct also in a sense.
There is no sharp cutoff at 400 or 700 nm.

Only thing that seems important is the fact they have evolved in a blue ( blue- green) rich light environment.

https://www.google.com/amp/s/orphek...rt-7-photosynthetically-usable-radiation/amp/

https://orphek.com/lighting-the-aquarium-part-8-orpheks-atlantik-v4-led-luminaire-par-and-pur/

Can't find "9" which would look at the other wavelengths. A shame.


As to spectrum and health, growth and pigment production ( visible and/or flourescent) pretty open to interpretation.

As to color ( if produced) well one needs excitation nm and/or reflective nm to see it.

Since the red sea led runs like 80% blue 10% white it would be higher pur than say a 50% blue 50% white if both measured the same par. What that would do ...??? and there might be competing factors of growth coloration and visual qualities which might even be species dependent.

Just an opinion though based on a collection of others thoughts.
Simple questions tend to have complicated answers.
A lighting source of high intensity (PPFD) and low useful output (PUR) has few practical applications, while the opposite is also true – low PAR output with high PUR is of limited usefulness.
Links above are a good read.
Screenshot_20221231-004138.png
 
Back
Top