Re: is it to early for co2 injection?

["James Purchase" <jppurchase at rogers_com>]

Matt asked:
"I have had my aquarium planted for about a mounth. My plants are got
off to a ruf start but there doing good, now. I want to inject co2. should
I? I also have 4 good size plants in a 2o gallon long aquarium, Is that
enough 02 to shut my air off? thanks   Matt"

There used to be a public service announcement on Canadian television which
had an accompanying jingle. The gingle went something like this - "Why wait
for Spring? Do it NOW!When there are men who know how...". For some reason,
Matt's question brought that old song to mind....

Matt, I assume that you're coming to plants from a "fishkeeper's"
background. Its never TOO EARLY to start CO2 injection in a planted
aquarium. The plants need the carbon dioxide. If you want to start using
either yeast based CO2 or the bottled gas, by all means, go ahead. Your
plants will thank you for it by growing better.

As for "shutting off your air", I assume that you are asking if its ok to
stop using air stones? Air stones are great to animate plastic ornaments but
a well run aquarium shouldn't need them - ever. The theory is that oxygen
will enter the water from all those tiny bubbles. I don't know about that.
The majority of the gas exchange probably takes place at the water's
surface. The only contribution an air stone would have is by inducing water
circulation, bringing more of the water into contact with the air. A small
powerhead (without the aereator feature) will do the same thing. You need
circulation, but you don't need effervesence. That would only serve to drive
the CO2 out of the water. You should not have your aquarium so overstocked
with fish that you NEED the help of an airstone. Plants will add oxygen to
your water, but only while their are actively photosynthesizing - at night,
they consume oxygen too. And 4 plants won't do much - get some more.

James Purchase
Toronto