PAR question and accuracy Neptune PAR meter

[nbd13]

I have a 150 gallon tank (5’x2’x2’) with 3 Radion G4 pros with diffusers over it. Mounted 16” off the water running custom AB+ at 100%.

I have a Neptune PAR meter and it’s only reading 318 at the top of my rock in the center which is about 8” below the surface. This seems very low to me?!?!

At the bottom of the tank I’m getting about 177!!! Just above the surface at the water I’m getting 523. Seems so low!

How accurate is this Neptune PAR meter? Seems very very low to me!

Any thoughts?

 

[dank reefer]

I use the same PAR meter, and tested my Radions XR30 G4pro par this weekend and I am getting close to 550 par. Light are set to 45% total intensity, but my lights are only 10 inches from the water line and I am not running diffusers.

Test with the diffusers off and see where your PAR is at. I've heard that running them with diffusers reduces Par by 15-20%

 

[nbd13]

Anyone else? Removed diffusers and for about 370-380 at top of rock work. Still think that’s crazy running at 100% intensity.

 

[Pete_the_Puma]

Three XR15's or XR30's?

For what its worth I think those numbers are reasonable, the diffusers do reduce output quite a bit.

I run 2 Gen3 XR30's and T5s on a 140 Gal tank at 90% output on AB+ with the lights a bit higher, maybe 18-20 inches off the water and get about 450-500 just below water with 250-300 on the top of the rocks directly under the Radions.

If your lights are fairly high and you want more output you could take off the diffusers.

I had tested with a Seneye and though the numbers were low, rented the BRS PAR meter only to find the numbers were almost exactly the same lol.

 

[dank reefer]

or just drop the lights from 16 inches to about 12-13.

 

[ADAM]

Per Neptun; PAR Sensor is great for T5..... LED not so much. Apogee stand-alone sensor is far better for LED. Don’t think the Apogee can be connected to the ASM module, it plugs directly into your laptop with software built into the sensor