advantages of co2

hey ive grown without co2 and had good results but id like to know what the advantages of using a tank would be and also where to get such an item or any cheap efficient ways to do without one....all advice welcome and appreciated

i made a diy co2 thingy from yeast water and sugar and i have seen improvement
they use co2 up around the leaves and they love it
it is like oxygen for us, so yea they can always use it

Get the big 50 pound tank and a regulator. Cheapest/easiest way to do it. Supposedly yields can be increased by 30% with its use.

how much approx. would that tank and reg. be?? and where do you get that shit?? a welders supply?

Yeah, welders supply place. Most cities will have many vendors to choose from. We can lease a 50 pound tank for $7/month here and refills are done every 6 months for $30 each. so Basically $144/year is my cost. 6 grows per year. If you buy the tank yourself your looking at several hundred each, then the regulator itself isn't cheap either , $150 or so.