On Tue, 21 Oct 2003 01:12:10 GMT, "Dan Drake" wrote:

_Plants_ in the dark remove O2 and add CO2; but the removal of O2 is what
matters. Adding more CO2 from a tank won't push out O2 unless you're
bubbling so much through the water that it acts like a de-aerator. (And

Actually, plants respire (consume O2 and burn stored sugars) all the
time, day and night. It's just that during the day, they produce more
O2 than they use.

(I'm not saying whether or not it's really necessary to do extra aeration
at night when you have plants. Anecdotal evidence says it is.

Of all the CO2 injected planted tanks I've seen in person, none have
needed or have used aeration at night. And I've had and seen some
incredibly densely planted tanks.


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