On Fri, 17 Jan 2003 02:48:16 -0000, "lynsey"
wrote:

I dont have additional CO2 added - but i have fish!!! they do that for me!

While I'm not saying you need CO2 injection (I've seen and setup many
planted tanks without CO2), the fish do not supply any measurable
amount of CO2.

Plants on land have access to approximate 350ppm of CO2 from the air.
In the water, the level of CO2 about 100 times less, or about 3.5ppm.

The tiny amount fish produce doesn't do anything for the levels. The
main source of CO2 from a non-injected tank is CO2 dissolving into the
water from the air. That is why, in a non-injected tank, it's
important to have good aeration and water circulation.

My 29g tank ran for several years with low-medium light and no CO2.
And last month, I helped a friend set up a low-tech planted tank, not
much light, and no CO2 injection. It's got some bba algae growth, but
overall things look pretty good.


Chuck Gadd
http://www.csd.net/~cgadd/aqua