T8, T10, T12 bulbs

[Rick]

I have some light bulbs labeled T12 and some T10 and see some in catalogs
listed as T8. What is the difference, they appear the same to me. And while
I'm at it, are 2 40watt (80w total) bulbs enough to support plants in a
90gal tank? Seems to keep the plastic ones alive :)

[Charles]

On Sun, 20 Nov 2005 22:20:49 GMT, "Rick" >
wrote:

>I have some light bulbs labeled T12 and some T10 and see some in catalogs
>listed as T8. What is the difference, they appear the same to me. And while
>I'm at it, are 2 40watt (80w total) bulbs enough to support plants in a
>90gal tank? Seems to keep the plastic ones alive :)
>


The "T" numbers indicate the outside diameter in 1/8th of an inch.

T8 is one inch, T 12 is 1.5 inches

[Steve]

Rick wrote:
> I have some light bulbs labeled T12 and some T10 and see some in catalogs
> listed as T8. What is the difference, they appear the same to me. And while
> I'm at it, are 2 40watt (80w total) bulbs enough to support plants in a
> 90gal tank? Seems to keep the plastic ones alive :)
>
>

T12 are the traditional, fat 40w fluorescent tubes. T8 are thinner, 32w
tubes used in modern fixtures with electronic ballsts. I have T12 and T8
around the house, but have no idea about T10.

The usual recommendation for plant lighting is at least 1.5w per gallon.
I'm using 5 T12 tubes over my planted 90 gallon aquarium, and it seems
to be enough. I cut back to 3 T12 for a year in an attempt to reduce
alagae, and the plants still grew.

Speaking of plastic, when I was a child we had some plastic fish as well
as real ones. The plastic fish floated, and were held in place by
monofilament nylon with a lead sinker. Does anyone remember these?

Steve

[Bill Stock]

"Rick" > wrote in message
...
>I have some light bulbs labeled T12 and some T10 and see some in catalogs
>listed as T8. What is the difference, they appear the same to me. And while
>I'm at it, are 2 40watt (80w total) bulbs enough to support plants in a
>90gal tank? Seems to keep the plastic ones alive :)

Damn, the Algae killed my plastic plants. :)


Rick,

I don't think 80 watts will do it for you. I'd want at least double that to
give you close to 2 watts per gallon.

If you prefer a different religion, a 90 gallon is 48*18 or 864 si and your
lights will only give you 6400 lumens (80 * 80 lumens per watt) when new.
The figures I've seen are 15 lsi (lumens per square inch) for low light
plants, 22 lsi for medium light plants and 30 lsi for high light plants. Of
course this all varies with the clarity of your water, the efficiency of
your ballast, the quality of your reflector, the depth of your tank (not so
much) and the phase of the moon.

If you're serious about growing plants, check out AH Supply. Great product
and service.

[NetMax]

"Rick" > wrote in message
...
>I have some light bulbs labeled T12 and some T10 and see some in
>catalogs listed as T8. What is the difference, they appear the same to
>me. And while I'm at it, are 2 40watt (80w total) bulbs enough to
>support plants in a 90gal tank? Seems to keep the plastic ones alive :)



As explained by Charles, the difference is diameter, and the smaller
diameter bulbs give you more light (but I can't recall the explanation on
that one, something about effective area facing the tank, or additional
space between the bulbs for top side reflection...).

My 120g uses 2x40W, my 66g uses 4x40W, my 40g uses 1x20W, so I'm not a
good example ;~). In the store, we found 2x40W worked well to 4' long
tanks of 18" depth. Longer or deeper tanks benefit from more light. Our
4' 100g used 4x40W. We sold 90g tanks with a 4 tube T8 upgrade for
planted applications. It's not essential but more expensive to change
later. I liked Bill's explanation on lumens per square inch, very
scientific.

In regards to plastic plants, I've killed these in a variety of
situations, usually involving large cichlids and the phase of the moon
;~).
--
www.NetMax.tk

[Rick]

"Rick" > wrote in message
...
>I have some light bulbs labeled T12 and some T10 and see some in catalogs
>listed as T8. What is the difference, they appear the same to me. And while
>I'm at it, are 2 40watt (80w total) bulbs enough to support plants in a
>90gal tank? Seems to keep the plastic ones alive :)
>
Thanks for the info.