Blue and white light par values
- Thread starter MohrReefs
- Start date
- Tagged users None
The PAR will be higher with the whites up higher, but this is a paper gain. The whites will be captured more with the meter which does not sample all light frequency the same. In the real world, this is probably equal to the corals. PAR is just a swag. If you want to do this, just go slow and look for your corals to tell you if they like it, or not.
A. grandis
2500 Club Member
- Joined
- Feb 15, 2012
- Messages
- 4,735
- Reaction score
- 3,429
What we see is not exactly what the PAR meter measures and it's not exactly what the corals "see" under water. Watching the corals is a practical way to "measure" what they ask about artificial light. The feeling is what give us the 5th sense in that regard, by experiences and sensibility, going slow. Back in the day no one had PAR meters (only Dana! Haha!). You boys are lucky to have that help, available today but just be careful in trusting it too much in every aspect.
It's so scary to read most posts from jda. He just writes my thoughts with his own words. I see things in a very similar way he does!
It's so scary to read most posts from jda. He just writes my thoughts with his own words. I see things in a very similar way he does!
"PAR" (Really PPFD) by definition measures the photon counts in all wavelengths from 400-700nm treating each "band" as equal.
Unfortunately life isn't so equal..so as mentioned above assuming your diode efficiency (photons/watt or photons/%) is equal between the 2 your "PAR"s should be equal with what you did BUT not all wavelengths have the same effect as others.
The term many use for this is "PUR" Phototsynthetically useable radiation.
PUR will differ between diodes with different spectrums i.e white vs blue.
So assuming your whites are lower PUR vs blue you aren't exactly equally changing things..
Example illustrating "pur" difference, sorry about the fuzzy chart.
Using high k whites (well low k as well but the "PUR" is in the red range but let's not complicate this too much) you won't be changing PUR by too much since the diodes are blue w/ little converting phosphors but you will change it.
What a say 10% loss (not a hard number btw) in pur with a 10% increase in output and a 10% loss on the blue side does is...
err..............questionable.
Regardless of what one grows large changes in spectrum is never a "good thing" and stability is king..
If you are going for a look thing then just as mentioned do it slow and keep in mind increasing white w/ a blue decrease isn't exactly equal in term of photosynthesis as currently understood but the difference applied equally and slowly shouldn't do "much"
You could get "fancy" and increase whites by 1X Pur factor of a 1 decrease in blues but that involves a lot of guessing.
YMMV..
Life gives few guarantees but knowing the differences gives one a shot...
