Why 57.6 inch t5 bulb consumes 16% more Watts per inch than 45.7 inch T5?

[biom]

57.6 in T5 HO - 80,5 Watt - 1.18 W/inch
45.7 in T5 HO - 54 Watt - 1.4 W/inch

The question is what does it mean? - is it gives 16% more light than 45.7 per inch or is 16% less effective - i.e. gives the same light per inch but consumes more power?
For me it is an important question because the difference in wattage of a pendant with 10 t5 45.7 tubes 540 Watt, and the one with 10 57.6 inch tubes will consume 805 Watt, 245 Watt difference for less than 12 inches length?

 

[mcarroll]

Is that based on the nominal ratings or actual performance data? I'm curious how well those two match....the 80 watt could have higher output in real life. In other words, yes more power per foot, but is it also more light per foot?

That's a question I'd direct at one or more of your favorite tube vendors to get their answer.

(Am I making sense? )

 

[biom]

Thank you, I'm not sure if the vendors could answer this question, but may be manufacturers? will try.

 

[mcarroll]

@ATI North America @ATI Aquaristik