Quote:
|
Please don't take any offense, but I feel tests done of bulbs in the air relate very little to what we are trying to accomplish in our tanks. There is no coral in sight, no water, and no organics in that water to dilute the light provided. I am much more interested in light values within the water column as everything changes when you break the surface. I only test surface values as a reference point to compare to other bulbs. If you notice the light drops quickly even right under the bulb as soon as you get below the surface of the water.
|
No offense, just a difference of opinion. I think both test methods have value and I am glad to see numbers in real tanks with water, coral, fish and rock. They are very helpful, as are just plain nice pictures.
All the variability you note above (organics, refraction at the surface, etc) is exactly why there is so much value in data collection in a controlled environment with air only. The more variables you eliminiate, the better you can answer the real question (that interestes me) - what does the spread and intensity of this reflector look and how well will it illuminate my tank?
I realize that the PAR values at a the coral in my tank are not predictable based on an air only test (not to mention bulb/ballast variability); however, you get a very clear idea of the uniformity and intensity of light incident at a given point from the bulb. This is very useful because the behavior of light once it enters the water surface is reasonably predictable and consitent. Understanding how the light behaves leaving the reflector is the real trick.
You are correct that the light values in the water column of MY tank is what I should be really interested in. Clearly the best way to choose would be for everyone would be to buy several reflectors and hang them over their tank and take measurements at all the various points of interest. I am not inclined to do this, so controlled grid measurements in air only are very valuable because they eliminate the inherent variability of tank tests. If, as you say, air tests relate very little to what we are trying to accomplish in our tanks, then one could certainly argue that values from your tank with your bulbs, balast, water, rock, etc are of little value for me and my tank. I do not think either of these arguments are true.
As for the # of posts that DaveIrk has, it is not of much consequence provided he chooses to continue with this discussion. Please be welcoming and hopefully he will us all learn a little more about these reflectors. In God we trust, everyone else must bring data.
Cheers