On Thu, 21 Sep 2006 21:49:19 -0500, southpaw wrote
(in article ):

Just a quick question.

I've got a planted seven gallon tank, cycled, with a male betta, 2
cherry barbs, and two corydoras trileanatus. I've been toying with the
idea of setting up a basic DIY 2 liter yeast reactor, as my plants
(some anachris, a red tiger lotus, and some didiplus) are doing ok,
but not much more better than that.

I've done my research. I have fairly hard water tap water that tests
out in the 1.2-1.3 range with slightly above neutral Ph, so I'm not
worried about buffer crashes. But since I'm just bubbling the CO2
straight to the surface and not into a diffuser, I'm worried that a
surface buildup might harm my surface breather. The hood on this tank
is vented. Will that be enough to keep CO2 above the water surface
from reaching toxic concentrations?

Thanks for any help.

Seven gallons? Just be patient. If your plants are growing at all, it won't
take them long to fill the entire tank. Also, are you maxed out on light? I
takes quite a bit of light to get to the point where using CO2 could help.

-E