C02, where to find a cheap system

[Brodie]

I just got a free 75 (hood, stand canopy, sump, VHO lighting etc) for helping my neighbor with his new 250. I'm planning on setting up a planted tank, and was wondering what I would need to do this..particularly C02.

Thanks.

 

[workfortheman]

http://www.aquariumadvice.com/showquestion.php?faq=2&fldAuto=41

"everything you need to know" according to BrianNY!! written by madasafish

 

[Hoovercat]

http://www.aquariumadvice.com/viewtopic.php?t=65609 Talloulou just asked the same thing (almost)