I have a 125 planted freshwater tank, I have two airstones in each corner, and running a filstar xp3 filter. I just set up a Co2 system (the semi-automatic) from drfosterandsmith.com Right now the bubble counter is showing about 2-3 bubbles per second, and I am getting a very fine line of co2 bubbles coming out of the diffuser. Is that good enough or should their be a lot of bubbles coming out of there? I know the co2 affects ph and so far no problems but for my plants to grow do I need to increase that a little bit?