RussReef

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Maybe someone could clear something up for me! :D

In reading this carefully,
http://www.advancedaquarist.com/issues/ ... review.htm

I think the wrong conclusion was reached with regard to DE AB 150 vs. SE Blueline 400.... R. Harker reports that Sanjay found 71.6 PPFD w/the SE Blueline 400 (bare bulb at 18"). He goes on to state that he found 76.5 PPFD w/the DE AB 150 (bare bulb at 18"). BUT, the conclusion in the opening paragraph is that the Blueline is more intense than the AB! Am I missing something here?

I think the problem was that the text following table 1, only discusses the SE AB 400 (135 PPFD bare bulb at 18") and the SE Iwasaki 400 (165.1 PPFD bare bulb at 24") -- Unfortunately, a comparison to the Blueline bulb (supporting the conclusion presented in the 1st paragraph of the article) was never discussed.

I kind of figured that the Iwaski's were "the strongest sun around." And, I probably could have guessed that the SE 400 watt AB's are more intense than DE 150 watt AB's.

Don't get me wrong. I think Harker is great for doing these tests! It just doesn't seem to me like the data support his conclusion with regard to the Blueline. Please correct me if I'm wrong. I certainly don't want to contribute to the urban myth phenomena.

It seems to me that the only way the SE Blueline 400 watt could be more intense than the DE AB 150 is if the reflector used w/the Blueline bulb magnifies the intensity of its bare bulb value by more than a factor of 2.7 (the"magnification factor" of the AB fixture he used, upon investigating table one):

207.6/76.5 = 2.714
124.1/45.4 = 2.734

Is the "magnification factor" of a common SE reflector (i.e., the spiderlight reflector) greater than that of the DE fixture used? Perhaps that would support Harker's conclusion with regard to all bulbs the bulbs he mentioned (including the Blueline) when enclosed in such fixtures.
 

RussReef

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I can't be the only one that noticed this discrepancy, am I? R. Harker, are you out there? I'm sure I'm just not understanding something, and I'd be truly grateful if someone would explain this to me. Thanks! :D
 

rharker

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RussReef":6k9djkjc said:
R. Harker reports that Sanjay found 71.6 PPFD w/the SE Blueline 400 (bare bulb at 18"). He goes on to state that he found 76.5 PPFD w/the DE AB 150 (bare bulb at 18"). BUT, the conclusion in the opening paragraph is that the Blueline is more intense than the AB! Am I missing something here?

I didn't write that the Blueline is brighter. I wrote that the AB bulb is not brighter. There is a difference in the two statements.

72 vs 77 is within measurement margin of error and bulb variability for these kinds of measurements. What it means is that we can't say that either bulb is really brighter than the other. The Blueline is not particularly bright compared to other 400 watt bulbs, so the comparison is not as useful as comparing the single ended to the double ended AB bulbs. The review was really about this comparison, not the SE versus the AB.

Richard Harker
 

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