Originally Posted by IceWish
...why is it that co2 escapes and o2 enters when the water is exposed to air....Why isnt it the other way around..does it have something to do with the gases....or is it just the same?...doesnt C02 like the water???
This might not be exactly right, so everyone else feel free to [kindly] correct me if I'm wrong. But the way I understand it is that both (all) gasses are driven off with surface agitation. However, fish only need air (not pure oxygen) to breathe and as you increase surface agitation, you also put a bunch of air INTO the water (as you also drive other air off). So there's a whole bunch of air for the fish to breathe, which is cool. The plants however, don't do so well breathing just air from the water. Instead, pure CO2 is much better for the plants so a surplus of air (being created by an airstone or other form of surface agitation) doesn't do them any good and in fact it causes loss of the vital CO2 that you're injecting yourself and that they very much need. Again, if this isn't correct, feel free to chime in, folks. 8)
Fightin' Texas Aggie Class of 2004
37 gallon AGA Black Seal, Emperor 400, Ebo Jager 200 W, 100% Flourite Substrate, 2x55 Watt AH Supply PC Lighting (5300K & 6400K) @ ~3.4 WPG, High-Pressure CO2.