Red Sea inquiry response about ReefLed 90 par value

[zafink]

Hello, I was wondering if you would consider this an accurate response to my question that I submitted to Red Sea regarding my reeled 90 that came with my e-170. They have a chart that shows that par for my tank with this light when light is at max, which is found here: https://www.redseafish.com/aquarium-systems/max-aquarium-systems/max-e-series/

I know that renting a par meter would be the most accurate way to get par on bottom of my tank right, but was wondering if others with experience would agree with the theory in their email that cutting lights by 50% would also decrease par value by 50%? With the sand bed the bottom of my tank has around 150 par, a bit high I'd think for my cynarina. The Email is attached. My initial inquiry is on the bottom. Thanks for any insight!

 

[blaxsun]

Yes, in theory I'd agree with their assessment - although it's going to be a rough estimate at best. However, they're also correct that the only way to know for certain is to take a reading with a PAR meter. Your rockscape, sandbed, etc. can all have minor effects on PAR levels.

 

[zafink]

Thanks! Just wanted to get a second opinion, much appreciated.

 

[oreo54]

Thanks! Just wanted to get a second opinion, much appreciated.

Minor complication ..
The "average" decrease in current and accompanied cooling of the diodes increases efficiency of energy to photon conversion.

In other words a 50% decrease in" current" may decrease par by only 40%.

Probably not a major concern though

 

[oreo54]

Oh also depends on " how" pwm is implemented.
Most are linear ( probably like 99%), rarely logarithmic ( gamma dimming).