Converting PAR readings with lower intensity

[Domizi]

Hi!

I have bought a red sea G2 nano XL for my first tank. It includes a ReefLed 50, which have a PAR map for the full intensity mapped out on their website for aquariums with the same measurements. My question is, will PAR be reduced in equal amounts as the intensity? I.E. if I reduce intensity to 30%, will the PAR be 30% of the PAR map? Or do I need to rent a PAR meter to know for sure? I plan on keeping softies/LPS, so won't be needing any higher readings.

A big thanks in advance for anyone who takes the time to answer!

 

[Formulator]

Maybe, but I would not make that assumption. Nor would I run your lights at 30%. I never understood why people do that with LED lights. Get your money out of them and run them at higher intensity. Corals will benefit, even if they don’t “require” higher PAR.

Most LFS have PAR meters for rent so you could rent one to tune your lights and make your own map. Your rock scape will affect the values, so the website map won’t be perfectly aligned with your tank.

 

[Mr. Mojo Rising]

In addition to above, keep in mind that if you have a lid that might reduce par, if you have dust buildup on your water surface it will reduce par, dirty lense reduces par, the older the light gets the more the par is reduced......... The guide is a helpful but in reality lots can affect the par output, thats why a par meter is best.

 

[Domizi]

Thank you for your answer! From what I understand the LPS and softies I'm interested in require PAR in the 50-150 range, and that higher PAR can be detrimental and cause bleaching. Isn't this correct?

The PAR map indicates PAR at 100 at the bottom of the aquarium, and a lot higher in the middle. I've also read threads about the light, saying it really is strong and needs to be turned down. I think I would go higher than 30% though, it was more just an example.

I will inquire with my LFS, was just looking if anyone else had any experience that would let me use an existing map instead!