mywebaccts (at) PLUGcomcast.net said:

The discussion of the use of T5/T8 5000 lights sparked my interest - as
I had no idea what it was - and I've found tons of information on the
internet about it. But as usual, weeding through the contradictions is
always difficult.

Some people seem to view the T5 as superior to the T8, both in energy
usage and in output. Then I've also found pages saying it isn't true.

A T5 seems very small to be that good at producing enough light ... but
some people say they do in fact produce the same amount of ligth.

Who out there is using these and can you give me your opinion on which
to go for? I have outlets in the ceiling out the gazoo ... so I can
install as many of these as I need. My concern is that I get enough
natural looking light, but without an UV since I burn easy.

Total light output depends on the phosphors and design of the tube.
Different tubes vary as to color temperature and total light output.
(Yes, even within families such as 4 foot T-8 and T-5.)
HO and VHO bulbs increase light output, but at a loss of bulb life and
higher energy consumption.

Look at the bulb specs. Standard T-8 and T-5 bulbs are very similar.
There will be a rating of total lumens (after burn-in).
Note also the wattage/current it consumes.
The CRI is based upon a physiological rendering comparison of the
color to noon daylight - the higher the better.

Extrapolate the lumens per watt for the selected bulbs. ~Efficiency.
Find out which type is most affordable in your area.
Buy based upon sound research.

UV burning isn't much of a factor with fluorescent lighting - perhaps
with specialty actinic or UVa/b bulbs, but not std illumination bulbs.
It is more of a concern with Metal Halides, especially if the outer
envelope is damaged.

FWIW,

Greg G.