If you're looking to increase your yields via the addition of carbon dioxide, the best way to integrate into your grow tent includes a variety of proven strategies.
Let's start first with the easy and most cost efficient, CO2 tanks. You can buy a 20 lb tank that will last you a few cycles for only ~$150. Some growers swear by co2 tanks as the most cost efficient, and we recommend using it with a co2 controller/regulator.
Next, you can also try two other options. Dry Ice is our second most effective after CO2 tanks. Third comes CO2 bags, which are mycelial mass fungi that happen to emit CO2. Dry ice only lasts for a week or two, and same with CO2 bags. With CO2 bags you'll have to hang them all over your tent for any kind of significant effect.
On a different CO2 topic, if you're using CO2 and high pressure for your cannabis extractions, be sure to review the new and advanced method from ESCET LLC, cannabis extraction consultants and expert cannabis chemist Joseph Payack.