Hello poker2,

That 2' fixture is a NO (normal output) fixture, the bulbs are 14 watts each.

You want a HO (high output) fixtures that would use 2' 24 watt bulbs.

Or if you want really crazy light output, build your own floro fixture with end caps etc, and use an IceCap electronic ballast and get 40 watts per 2' tube.

A two light T5 HO is good for clones, seedlings and veg.
Flowering you would need a little more light, plus 3000k bulbs.

Hope this helps you.
OM