T5s for Phal Seedlings

[Undergrounder]

OK so i'm new to T5s... and lights... pretty much everything.

I have a shelf system where i plan on growing Phalaenopsis seedlings. There are 2 shelves (3 including the base), and i plan on suspending a thin T5 fixture under each shelf (and one on top) to create three levels of growing space, each level with its own T5 lights. I hope that makes sense.

Anyway doing this, the Phalaenopsis would probably be just 10cm or so away from the lights, and i would like to know how powerful my lights need to be at this distance. I could get 2, 3, 4 or even 8 bulbs per shelf, and those bulbs would be either 28W or 54W, depending on the make of the lights.

I don't want to burn the things, but i need good light... so how many T5s (at 28W or 54W - depends on the maker) should i need for Phalaenopsis seedlings at about 10cm distance?

Thanks!