AI Prime and Par

[MikeDesjean]

So today a friend came by with a par meter quick to help map out my tank. I was running lights at 110% with some of the blues turned down a little say 95%.

Anyway, we tested a spot where u had hammers and it was 47 par! We turned the lights up 20% to 130% power and it got to 70.

my question is. If it was to raise lights to say 150% another 20% increase would that par reading now become 93?

is par a linear? If it divided it out 1% increase is 1.15 par. Am I correct in my thinking?

 

[Deep Dive Aquatics]

Out of curiosity how big is your tank and how high did you mount the light. Also how old is the fixture.

 

[MikeDesjean]

My ai prime is I think 10”. I set it to the BRS recommend height for WaterBox 20. And is about 9 months old right now

 

[MikeDesjean]

Out of curiosity how big is your tank and how high did you mount the light. Also how old is the fixture.

Going to write pars on top of a pic I will post when done

 

[oreo54]

So today a friend came by with a par meter quick to help map out my tank. I was running lights at 110% with some of the blues turned down a little say 95%.

Anyway, we tested a spot where u had hammers and it was 47 par! We turned the lights up 20% to 130% power and it got to 70.

my question is. If it was to raise lights to say 150% another 20% increase would that par reading now become 93?

is par a linear? If it divided it out 1% increase is 1.15 par. Am I correct in my thinking?

Beware of simple questions...
Answer is maybe roughly linear.

Starting with the fact that as one increases the current to the led it starts to lose efficiency.
Say you get 50 par at 350mA and you increase it to 700mA.
If linear par would be 100 but unfortunately it would more likely be say 95 due to the conversion efficiency droop.
Depending on design and chip quality this loss can be low to moderate but regardless not quite linear.
Then there are the dim curves ( linear or gamma, most are linear in aquarium lights) applied to the dim signal.
How it's dimmed i.e pwm or current control.

To be honest most can be ignored.
Except gamma curves but I believe quote uncommon.
In environmental lighting it gets more attention.

Last is balancing different " colors"
There are drive currents, numbers of diodes, and quality differences.
One can't dim say 5 5w blues 50% and proportionally increase 3 3w whites 50% and expect equal par.

Changing par by raising or lowering lights has its own set of issues.

Best to just use real world measurements.

 

[MikeDesjean]

Beware of simple questions...
Answer is maybe roughly linear.

Starting with the fact that as one increases the current to the led it starts to lose efficiency.
Say you get 50 par at 350mA and you increase it to 700mA.
If linear par would be 100 but unfortunately it would more likely be say 95 due to the conversion efficiency droop.
Depending on design and chip quality this loss can be low to moderate but regardless not quite linear.
Then there are the dim curves ( linear or gamma, most are linear in aquarium lights) applied to the dim signal.
How it's dimmed i.e pwm or current control.

To be honest most can be ignored.
Except gamma curves but I believe quote uncommon.
In environmental lighting it gets more attention.

Last is balancing different " colors"
There are drive currents, numbers of diodes, and quality differences.
One can't dim say 5 5w blues 50% and proportionally increase 3 3w whites 50% and expect equal par.

Changing par by raising or lowering lights has its own set of issues.

Best to just use real world measurements.

Hey, thanks for the info. I wish I had a par meter on hand for a week or so that would be ideal. I thought the quick map was going to be good until everything was so low and got it an execrable level for what I am looking to do.

I was just hoping for a rough equation if I wanted to get more par in all the spots to keep some stuff lower vs higher.

i had a feeling it would not be as simple as I raised it x and raised par by y and now I can find out how much par goes up per 1% light increase.

from what I gather from you, I am half right? If I did I should expect to see slight reductions in par gained as the lights go up.

I wish I new more about dim curves and mA but I have no clue lol

I am happy ish with were I am at now. Just going to have to move some stuff around

 

[oreo54]

You first need to maximize position to maximize par.
Then dim accordingly.

There are a couple of things they don't quite get but overall an excellent presentation