it would be much easer and you will get more co2 if you mix it with a good bottle of booze and talk to your plants.
One 40 pound tank of co2 will make a 5000-10,000 sodas or last a large grow room about 2 monhs at 1500 +- 50 ppm.
Note just normal breathing in a large room will up the co2 levels about 600 ppm over normal earths 300 ppm of co2 .
But if your real rich go for it