What do you use for 8 tube fixtures?
I'm currently under 4 tube fixtures. I even managed to rebloom a
Den Super Ise under this arrangement and most of the plants are going
nuts, but there are a couple that have the dark green "I want more
light" thing going.

I use 4 Simkar ST240RS I bought at Lowes for around $20 I'd like to show
you them on the Lowes page but it says they do not sell them even though
they had them at the lowes store the other day. how ever here is a page
with a picture.
http://www.hardwareworld.com/St-240r...e-p5GDUA5.aspx

FIRST AND FORMOST you must know how to wire a fixture before start to use
these as they do not come wired. I shout because this is very important.

I get my power cords at a local computer junk/resale store for $1 each. You
will need a strain relief for each fixture also. I put the fixtures side by
side and use a combination of cool white, day light and wide spectrum
tubes. I grow and bloom catts, dens, phals, onc.and paphs under them. The
catt leafs look the same color as those grown outside under a 60% shade
cloth.

I run three shelves isolating each self from the one below with 2 inches of
pink or blue construction foam which comes in 4 X 8 foot sheets.

The lights are just high enough on each self so that the leaves do not
touch them as even fluoresents arre hot enough burn the leaves.

Grow well and bloom magnificently
dusty