Well, of course, there's going to be varying opinions regarding the best all around choice of lighting for your plants. Personally, I think the lighting fixture you linked too cost much more than you need to spend. First of all, T5 bulbs cost about twice as much as T8 bulbs and they do not perform twice as well. They're not twice as economical either. There's a good webpage that explains about that, see link below.

You can get 4 foot shop lights (with reflector) for T8 bulbs at Home Depot for about twenty bucks and the bulbs cost about 3 or 4 bucks each.

I have both T5 and T8 lights and much prefer the T8. Not only because of the price, but because the T8s don't get near as hot as those T5 bulbs do. I just bought a box of Philips 4 foot T8 bulbs called "Daylight Deluxe". They're 32 watt bulbs rated at 2750 lumens, 6500K color temp, and they cost $3.39 each.
A four foot T5 bulb is usually rated at around 2480 lumens and cost about $6.00 each.

Just my opinion,
Art

Here is a link that might be useful: T5 or T8

Thanks!

I looked up the bulbs you were talking about (t8 daylight deluxe) and some people were saying that they burn out really quickly. Do you find this to be true?

As long as I get a bulb that has sufficient lumens and color temp will any T8 work or does it need to be marked as a "grow light"? Is 4100K enough, or should I have higher than that?

About the possibility of the bulbs burning out ... I just bought the box of t8's last week so I can't really say how long they'll last. On the box it says they're rated for 30,000 hours. The t5 bulbs in your link are only rated for 20,000 hours.

Actually, I've never had any of my fluorescent bulbs burn out. That's because at the beginning of each growing season, I check all of my lights with a light meter. When they're only about 80% of the original brightness, I just replace them. I'd have to think twice about that if I were paying over six bucks a piece for them :-)

Regarding your question about the lumens and color temp, yes as long as you get a bulb that has sufficient lumens and the color temp you want, any t8 or t5 will work just fine. If the bulb is marked "Grow Light" you'll just pay more for it and see absolutely no advantage.

I'm sure no expert on lighting but I think 4100K bulbs will fall into the cool white area. That is, where the blue and red parts of the spectrum are about even. 6500K enhances the blues and tends to flatten the reds. That's supposed to be better for vegetative growth and since that's what I want (don't want flowers yet), that's what I've always used. You might want to google that for better information :-)

Hope this helps,
Art

This post was edited by art33 on Sat, Mar 2, 13 at 13:47

What kind of light meter do you use?

I have a 'DrMeter Digital Illuminance/Light Meter LX1330B' - They sell for about $40 and are very handy to have around.

Just the cheap walmart shoplight is good, make sure it runs 32 watts at T8, and buy a lamp with higher numbers of lumens, and cool white is good enough.