Whenever I get the 660 I will get a 6 ATtube fixture to see for myself. But based on the numbers, if people are happy with T5's(I always have been), they be happy with these too.
These
pics are not mine but a guy who got 4 right away. He has 3 hydrotubs for veg, 2 hydrotubs under T5's(4bulbs,231w) and 1 hydrotub under ATtubes(4tubes,78w). Those are the wattages he measured with a watt meter.
ATtubes left, T5's right.
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These are the same 19 days later. T5 have a little more growth but considering that they use 153w more(231w vs 78w), I think the difference is acceptable. The tubes are ridiculously cool too, and it's a very noticeable difference between the tubes and T5 temps.
Apache tubes
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T5's
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