How do you use CO2 on a tank?

[rcombs]

Nice planted 10. I am going to do a planted 10 with cherry red shrimp. Will be running by end of day, shrimp come in tomorrow. Also, the DIY CO2= Success. My plants have become so green they look fake. The tiny tiny bit of algae I had has subsided. For some reason fish look happier. IDK if it has anything to do with it or not, but two days after I started CO2, Spawning was triggered. Probably just coincidence.