Help me understand my PAR

[HM3105]

Hey all,

 

So I borrowed a PAR meter (Apogee MQ-200) from my local club and I decided to take some readings for my DIY Cluster. I was kind of suprised as I expected them to be higher

 

Directly under light - 155 12" away from light

Off center - 100 13" away from light

Sand bed off center - 90 20" away from light

Corners - 80 24" away from light

 

 

I use a Coralux Storm X below are my channels and settings

CH1 - 2 BXRAs 800

CH2 - 4 Luxeon M 2800

CH3 - 4 Rebel blues, 1780

CH4 - 2 Cyan 1780

Ch5 - 12 violets (combination of Hyper and True) 2800

 

So, I know that the PAR meter doesn't read the blue and violet very well so I was wondering if these readings look about right or not. Too me I guess I was expecting 200's directly under the light and low 100's on the sand bed. Was I expecting too much? I still have the PAR meter so I can take more readings.

 

Thanks for your help and advice all

 

 

 

 

 

[afyounie]

I just bought a SQ-200 electric sensor and tested my DIY LED setup. I have 14 RB, 7 CW, and 7NW. At 100%, I get a PAR reading of about 200 approximately 6 inches from the light. At the highest point in my tank which is about 12 in from the light, 150. This is about mid way down. Bottom of tank is around 100. Yeah these sound low, but I can still grow SPS. I can't even keep my lights at max because it burns my corals, SPS included. I keep the lights turned down to 30%. So take these readings with a grain of salt and go by what you can see. If your corals are growing, then your levels are good. If they start to bleach, then the light is too much. I tested my sensor outside and in the sun I get 1500 PAR. Under a 6500K CFL, 20W I think, ~120 PAR. The aquatic plants I grow under the CFL grow amazingly well.

[Nano sapiens]

You have a lot of violet in there and the meter reads a combined violet/hyperviolet at maybe 30% less than true PAR. Taking the violets into consideration, IMO you could add roughly +20-25% to the PAR meter readout and be 'in the ballpark'. Mind you, this is not an exact PAR reading, but an approximation. You can learn more about how the PAR meter reads various wavelengths on the Apogee website.

 

For my DIY LEDs with much less violet but proportionally more RB, I read ~250 PAR at 10" depth directly under the center of the array (I use a +15% correction factor).

 

As long as the corals have good color and at least some growth, no need to worry