said by leibold:
How did you get to 1/2 the power consumption, did you reduce the number of fluorescent tubes ?
I used GE UltraMax L series ballast.
Claims to use only 49 W with 2 tube. Given the series has multiple ballasts I'm assuming they are running bulb at less then maximum wattage. From what I have read about T8 retrofits they are brighter then T12 so I took a chance. Visually they look the same but that is logarithmic. My wife has a light meter for plants so in an unscientific test of light output they seem to be about the same.
They are available at subsidized prices through the NH saves program for $14 a ballast for two tube unit.
T8 tube prices are all over the place $2-6 per tube. I found a contractor package at Lowes.
The Sylvania site says they do not meet 2012 energy requirements but have been grandfathered due to rare earths shortage. I don't understand since the Lumen output is the same as much more expensive bulbs.
I believe a 2-tube T12 magnetic ballast comes in about 90W. Which is how I came up with the 50% power saving, I did not actually measure it.