@saltyfilmfolks ....
OKAY... SO... What would you suggest for the "lighting AND reef newbie" to do with their new LUX meter? What would be the best process for evaluating a new light purchase? What 'numbers' should we be trying to target?
I know... it's a LOT to ask for..... aaaand the 'answers' arent so easy.
Hahahaha. Well......
For a total newb, your likey up a creek. ;Wideyed
For a newer newb, look at the tanks that you like and the par that those tanks run in By asking questions and looking a tank par charts and note what are high med and low light coral.
Look at manufacturer Par specs and the distance from the light they are taken at. Those specs are given at full power and 1:1 color ratios. Choose a light that meets or exceeds the par specs you want or need. Manufactures like AI and Radion offer several different models with with different power levels.
(I think its worthy to note here, that along with Dana R's work, this is how I confirmed the the number 60. I compared several of my lights lux readings to the published par charts they lined up almost exactly)
Even though I am metering in lux, I am at all times thinking in par.
I've spoken to folks who actually do the opposite. Mainly because it's easy and its simply a quantified number to follow. IE 22,000 lux doesn't seem enough, bump it to 26,000 lux, and see how it goes.
Run the numbers. Take an arbitrary luc number and divide it by 60(my prefered) but also 65, 70 and 75 and also 50 and 55 and note the very slight change in par.
Do that again with the lux number of 6000. I consider that one important. 6000 lux at 60 is 100 par.
So when you get your tank, set the lux at the top of the water on a best guess for par you want, then drop it 50 to 100 par to acclimate. Now you have a solid number to slowly increase or decrease the intensity. 6000 lux or 100 par, or 3000 lux or 50 par.
And yes, guesstimating the amount of blue and other color factors that change the conversion constant of 60. More than likely, its closer to 70 than 60. We love too much blue.
Some may say this is not precise, but if you speak to Par meter users its very much the same process as they search for the "sweet spot".
Once you set an intensity, minor color changes are IMO, just that. Minor, and likely effect both par and lux minimally.
Additionally, if someone has their tank set up just like yours, you can copy all of their colors, and match the lux. And subsequent par.
You can also go to the lfs, and see how much light is over their tanks when you buy a frag. keep in mind most don't propagate coral , just store it till you buy it.
I also do recommend, (as a Gaffer, Photographer, and reefer) Wander around the house with the meter. Go out side. It helps to understand how very little, or hoe very much light is around us. This IMO, will hlep later as you set the ramp time and levels to not exceed a maximum DLI. The amount of light I have in the am and the very last of the PM is less than you have in the bathroom. But I can see the tank quite clearly at 75 lux. My keyboard right this second is 46 lux and the windows are all open.
. However, the corals we keep come from anywhere between 1 meter of water depth to 20 meters of water depth or more. So the actual lux readings on the reef will be dampened significantly by water attenuation. In our tanks, water attenuation is insignificant (0.2 meters on average) relative to the spread of a point source at square of the distance. I'm not sure how these two losses compare. I guess my point is what Lux would be needed at the surface of a reef tank so the corals are getting a similar lux as they would on a reef when accounting for water adsorption of the light.
