Hi I am new to this site and a 2 crop veteran lol. I just grew my first crop of Sinsemella after a failed first attempt, anyway i grew it in a simple set up using 3 gallon pots filled with coco peat and hand watered with pre mixed veg nutrients and flowering nutrients purchased from a hydro shop. My grow room gets lots of fresh air flow through gaps between the wall and ceiling( the room is under the house) I am happy with the results from my first crop ( ready to be picked in a few days) but i am looking to improve on the future crops. The room should be getting a lot of of co2 from the air outside and my breathing from frequent visits to the room. The plants grew very quickly and healthy looking but i am still wondering if more co2 would improve things even more. I don't want to go out buying co2 tanks and stuff when i could probably leave good enough alone. I work in a tavern and i have access to unlimited supplies of soda water from the post mix machine. I know club soda has sodium in it but i am not sure about water mixed with gas straight from the tank. Anyway if anyone knows if it does contain sodium i would appreciate finding out. If it does not i was thinking about using soda water mixed with nutrients and watering my plants with it, or maybe just spraying the leaves.