Really just depends on where your growing. A smaller grow space would probably be a lot better of that canister thing. Co2 really helps if your have lots of green and not a lot of space. I'd recommend growing a few plants first then trying to increase your output with Co2. Co2 should be monitored before even being worried about it, not much sense in adding extra co2 if you already have enough co2 in your house. And the plants definitely can see a benefit from it growing in ideal conditions with a powerful light. And it's more important in later stages then it is in early veg. You wanna have more co2 going in as the plants get bigger and breathe more. You'll get better yields from proper nutrients and plant care then you will with the extra Co2. Anyway I hope this helps and happy growing.