The tester only tells you how much you HAVE.
You need a CO2 injection system if you want to do it right, or a burner-generator.
There is a section in Rhizome's grow setup thread about calculating the CO2 needs of your garden and supplying them with a tank system.

If you have never grown before, it is highly unlikely that CO2 will be your limiting factor...
stinkyattic Reviewed by stinkyattic on . Co2 on the cheap Just wanted to know if anyone knew the best way to get bang for your buck in a decent sized operation of about 60 plants in a master bedroom. Also if anyone could direct me to quality articles and info on it. thanks!! Rating: 5