Quote Originally Posted by Monophoto
Both boxes had problems getting all the tubes started - solution was to look, and then reach in and tap the tubes that wouldn't start. That's a problem with tradtional fluorescent tubes that you don't have with spirals.
If all of the tubes are tied to a common ground they should all start at once. Another thing that you should do, if you make a unit with the bi-pin holders, is to place a sheet of metal at the top of the box, behind the tubes. Or, alternatively, just lay a bare wire over all of the tubes at the side.

A unit built from two-tube commerical holders does not need the sheet metal or the wires since you have this already in the metal holder. Just be sure to ground all the tubes. I have a twelve tube unit of 48" tubes made from commercial two-tube fixtures. All of the tubes are tied together, including ground, in the power outlet. Every tubes comes on at the same time in this unit.