How much co2 should i put in my tank?

[Hagermanfd]

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?

[jpappy789]

You should get a drop checker if you don't already have one already. Someone else should be able to point you towards a specific brand.

[tanker]

Are the airstones attached to the CO2, if not get rid of it.

The only way to know if you have the correct amount is with a drop checker.
If not stay on the low side till you know.

[7itanium]

unless you are using the airstones for the CO2... get rid of them ASAP or your CO2 isnt doing jack

adding air to the tank is just wasting your CO2

[Hagermanfd]

The airstones were for air only, no co2 was going through them, I did some research i had no idea that the air would drive out the co2, I guess the plants will help add oxygen to the water so the fish will not die. So far my ph has been 7.2 - 7.6 Should I leave the co2 on all night or should i turn it off when the lights go off? I heard by turning it on and off it will cause ph crashes...Is that true?

[Cerianthus]

Wouldnt add CO2 at night. You may not need to add CO2 in the morning either since no lght, no photosynthesis thus More CO2 will accumulate overnight just from fish (sometimes too high to a point to fish can suffocate if your tank is overstocked). As day progreeses, plant will use up CO2 thus should add CO2.
If you have good pH test kit (digital probe), should be able to determine when to add CO2.
Even w/ liquid test kit, should be able to see differences in pH at dawn and sunset.
Use pH test result as guide as low pH means more dissolved CO2 than high pH.
Of course, digital pH monitor/controller will give you more accurate readings.