All the DIY c02 systems are only good for 2-3 plants. Even then its just an "added bonus" and you really cant calculate any real results from it.
I havent started dosing yet because Im getting my c02 bottle next week. I wasn't expecting things to come along so fast.
All the DIY c02 is alright, but lets break down the real costs.
I can rent a 20lb C02 tank for $70/year for the tank. I could buy one for a few hundred, but then I would be responsible for maintaining and replacing the tank. $70CDN a year to rent is great!
If I own the tank, or if I already paid the 1 year rental, Its only $35 CDN for 20lbs of pure c02.
The only other thing you need is a one time cost, $200 for an electric regulator and timer and your good to grow.
So total cost per year for c02, after the upfront cost is about $100 a year.
And thats not $100 for yeast, buckets, sugar, and all the other crap you will spend money on (TAPE) But thats $100 for pure c02 that can be injected and calculated to IDEAL conditions, no risk of mold, no replacing dirty buckets, just refill your tank once every few months.
Best part about a bottle, you can actually SEE the results.....Then you can smoke them