Radion XR15 Pro Gen 3 lighting % question

[cobraz]

For all the people that have a Radion XR15w Pro Gen 3 LED Light.

I do not have a par meter but I have been on AquaticLog's site and looked at there EcoTech page.

What % do you run your light at based on these factors.
1.) Light is mounted using their tank mounting arm.
2.) The sand bed surface is 16" to the tank rim + the Arm height 8" to the light surface.
3.) I have and will have SPS Acro's and LPS and Zoas.

Currently I am running the light at 60%... trying to figure out the optimal % to run.
The tank is a Nuvo 40 24" L x 20" W x 19" H., with a 3" sand bed.

Any help would be great....

 

[mcarroll]

Get a lux meter and use that instead. It will work fine for this purpose.

Start with a free lux meter app for the camera on your smartphone.....Galactica Luxmeter seems to work for everyone on iPhone who's tried it, but there are lots of them. Android has them too. A $15 handheld lux meter is a smart buy, but you have to wait for delivery.

100,000 lux = 2000 par = "direct sun" at sea level, just for reference.

20,000 lux to 80,000 lux seems to be the acceptable range for a reef tank - where most coral will be unstressed and happy.

To start with, I'd target around 25,000 or 50,000 lux - low or mid values within the good range. I only go up toward 80,000 lux when needed....and I don't find the need often. Most corals seem happy with moderate lighting. (More is not better.)

 

[mcarroll]

I can add this to the equation/considerations...

• If you're running the 80º lenses, you're going to need about 12" of mounting height off the water for "full coverage", which I figured as a 20" diameter spread. "Perfect coverage" in terms of the math....you have to be the judge.
• If you're running the 120º lenses, you will begin spilling light out of the tank above 6".

This is mostly for reference since you have the mounting arm.

The arm is fixed at 8" from the water, correct? If that's right - you get these options for light spread...

• With the 120º lenses you get a 28" spread.
• With 80º lenses you get a 13" spread.

If it was up to me, I'd run the 80º lenses at 12" off the water on your tank. Just for $0.02.

I suspect at only 8" high the 80º spread would still be fine even though it's coverage is "short" by three inches all the way around. But I'd really like to know the peak lux measurement from each lens setup at 8".

Once you know that, picking your final intensity is a snap.

Any chance of trying that free lux meter app?

 

[cobraz]

I will download it today ... now the funny question:
I know I am not going drop my iphone in the tank center bottom to get a reading.....
So how true will it be holding it outside the tank at the sand depth ?