T8s vs T12s

Boredomb

What exactly is the difference between the two (besides the obvious size)??
If you have 2 natural daylight bulbs one being a T2 and one being a T8 would plants respond different to one or the other??? I can't seem to find 24" T8 daylight bulbs locally anymore but I can in T12s. I don't really wanna have to buy a specialized plant bulb at a fish store if I don't have to. They are about twice as much as the regular daylight bulbs I have been using.

Byron

There is a difference. T12 are the old "original" fluorescent tubes, and they are being phased out by I think all manufacturers. The T8 are more energy efficient, because they are better made and they use less mercury so they are more environmentally-friendly. As an example, GE Daylight 48-inch in T12 is 40w, but the same tube in T8 is 32w, yet it produces slightly more intensity. So less energy, less mercury, and a tad more light. I always get T8 if I can, but in smaller sizes the stores around me still have T12. Home Depot over the past year or so has replaced the 48-inch T12 with T8, although this is more likely the manufacturer than the store. They still have T12 in the smaller sizes, though I see some are now T8.

Byron.

Boredomb

The 24" bulb is the problem for me. I can get T8 daylight bulbs in 18, 36, and 48" but not 24" for some reason Lowe's or Home Depot don't have them. I don't know if its the store that's just not carting them or if they can't get them (I imagine its the store that's just not carrying them.).

So the difference is T8 is a little more intense then the T12 but they are more energy efficient. Until I can find some T8 in that would T12 be okay for plant growth?

Byron

Hard to say. And I have the exact same issue. My 24-inch Life-Glo tube over the 29g was wearing out, so I looked around and finally got the T12 in the GE Daylight. I can barely see inside the tank. But, I'm leaving this for a time to see if the plants fall apart or not; after several weeks, they don't look very good, so it doesn't look promising.

My former tube on this tank was a T8 Life-Glo. I can't find any locally, so I decided to experiment with the GE. The Life-Glo are in T8 now, but they produce more light intensity to begin with, much more, because they are made to. The ZooMed UltraSun is very similar [I can't get these locally at all].

Boredomb

ok, I might just break down and pay the extra money for a Zoomed UltraSun as I can get it locally in 24".

Reefing Madness

T-12 bad light
T-8 better light
T-6 much better light
T-5 much much better light
The smaller you get into these, the more efficient and more usuable light they produce.