I have been growing "Tropical Plants" for decades under good old "shop
lights". Normally with one cool white and one warm white tube per
fixture; for flowering plants I might add the special wide spectrum
tube. If the particular set up has 2 double tube fixtures, I place the
W-S tube so they are in the center and one warm and one cool at either
end. W-S tubes are not necessary for starting and growing seeds and
seedlings. I do keep the fixtures fairly close to the tops of the
seedlings, 2-inches seems to work best..

To reflect the light back onto all parts of the plants/seedlings I hang
the silver Mylar coated "Survival Blankets" on three sides of the plant
stand, leaving the top open for heat escape.. The front can also be
draped with these survival blankets or you can use clear plastic, but I
have found this impedes air circulation and can get the area too warm
causing the potting mix to dry out too quickly.

I have grown and flowered just about everything fromAfrican Violets to
Zygo-cactus under this set-up with great results.

Hemma