HomeMade C02? & For How Long?

Im making C02.. but my question is exactly where should i place it?? anything that i should look out for like not to close to the lights not near a fan to strong? do's and donts?.. and most importantly HOW LONG!? to my understanding the c02 will keep flowing as long as i have the hose end on it.. should i switch back to a closed lid at any time?

you could place the cap back on at night, but not really needed. this is because plants dont use co2 at dark, but the cooler temperatures at night should keep the pressure down so very little co2 would leak to begin with. also. put it up higher where its warmer, dont let light into the bottle as itll kill yeast, and put it opposite corner of your fan. remember co2 is relatively heavy so it will want to sink tothe bottom of your room, but it will also go with the air flow from exhaust fan.

you should be able to figure out the rest

alright.. appreciate the info..