Well, After a little while of tinkering and reading i finally took measurements. Now its in PPF which if i found out online is a unit of PAR. Or something along those lines. Here are my tanks.
The main tanks is under a 4 bulb ATI t-5 fixture. 4x39watts. 2 Blue 1 white 1 pink. These reading are what i expected, and i was surprised how much light dissipated under the water.
Now this is the frag tank. The red numbers are what the par is under the eggcrate i have shading the middle area. I am very surprised. All the corals mostly Zoa, are extremely bright and very very light. SO i was thinking for sure there must be higher light in this tank being so shallow then with the t-5but i was wrong. Its weird how they act so diff even when the light is lower. This tank is lit by a 2 bulb Coralife pc. 1 460 act and a 1 10k. i think 96 watts total.
There are my results, just thought i would share.
Update.
Well, Shawn asked me to get exact measurements, and compare Black and White eggcrate. Furthermore i went on to test both sides. My results are interesting, but they are just what i predicted. Enjoy, and please comment.
My interesting thought. I found it interesting how the values get closer together as the probe goes deeper. I guess this makes sense because at that point the light has been refracted through 20 inches of water, and the waves all dissipate to the same level. I also found it interesting how much worse Black eggcrate was than white. Thought white would have reflected more back at the light.
Pardon the dirtyness, i didnt bother to clean…
thank you for sharing!! very interesting to know. i really need to take readings and im intersted to see how the compare to yours since im also using 39w ATI’s over my 265g. could you provide the approximate depths of your readings. maybe distance from water and distance from light?
also. Fantastic info regarding the eggcrate!! any chance you could lay a piece of eggcrage over your main tank to compare the differences? and maybe take readings with eggcrate facing up and facing down? its claimed that the difference is substantial because the plastic is tapered to diffuse the light. it would be interesting to see just how substantial the difference is! maybe something like
[u]no eggcrate [/u] [u]eggcrate up[/u] [u]eggcrate down[/u]
x" ___ ___ ___
y" ___ ___ ___
z" ___ ___ ___
Ya ill get on that tomorrow. I can try. the hard part is keeping the sensor in place with eggcrate on, but i will find a way… I will also type up a formal post with the all the details neatly written…
Updated with new info, a chart, and my thoughts on my experiment.
some of the data is off a little, bit and there is a little user error, but overall pretty solid.
My results are interesting, but they are just what i predicted.
Really? Because you predicted the opposite of what most people say is a fact: the orientation of eggcrate matters. ;D
It would seem that up or down doesnt really matter one way or the other. The difference in color makes sense to me because the white will reflect but also channel the light through the eggcrate where as the black will absorb the light more. Interesting results. Thank you!!
Ya, i thought it would not make a difference, mostly becuase they didnt label one side over the other. Well now we know its not fact…
Now that i think about it, anything the white does reflect would reflect back up to the reflectors. one thing i did notice is that the area around the tank, and above it was much brighter with the white eggcrate…
Wait your saying it is fact that the side you put the eggcreat on doesn’t matter? Wither it is upside down or not?
That seems to be what his numbers are saying. It clear that the one side consistently has higher PAR readings which is obviously the side tapered toward the light source but it seems fairly insignificant to me in light of other factors(pun intended!) ;D Certainly not as significant as some people have claimed but i would imagine the differences could vary from manufacturer to manufacturer.
Yes, the datas variability is not statistically significant enough to reject the hypothesis that there is no difference. It wasnt surprising to me. I dont even think that there is a difference. As anyone who uses the meter knows, is that there is never a constant reading, it is always jumping around 20-30 par so i tried to sample when it is in the middle…
65 gal 75gal
3"/7" [not in h2o] 576 455
surface[just below surface] 430 363
7’ below 198 230
19" below 119 178
27" below 78 135
65 gal tank 6 t5 39 watt nova extreme fixture, bulbs under 2 months old [slm paq/current mix]
light 3" above surface
75 gal tank 6 t5 54 watt tek fixture, bulbs 3 months old [5 geissman, 1 current]
light 7" above surface