Mike, it's quite important for you (and your fish) that you know the concentration of CO2 in your tank. To do this, you must have a means of measuring pH and KH (carbonate hardness). With these two measurements and the use of a chart http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm you can read off the CO2 concentration in your tank. You should be looking for 10-25ppm. The amount you need to bubble in depends on your filtration system and the amount of surface agitation you have, plus of course how much the plants are using.
I would guess with a 35 gall tank, 1 bubble every 2 seconds would be a reasonable place to start, but do the measurements first.

Paul Davies
"Mike" wrote in message ...
I just purchased a CO2 bottle with Bubble Counter, Reactor, Valves, etc
etc... I'm a bit of a newb when it comes to this because I've never owned
one before.
How many bubbles should I be seeing passing through the counter? What is a
safe amount without killing the fish? I have a 10lbs. bottle of CO2 and a
33 gallon tank. I know the bottle is kinda overkill but I got sick of
buying the co2 tabs.. I don't wanna kill my fish that I have in there right
now. I'm guessing the CO2 is regulated by how much I turn the knob on the
bottle?

Mike