cheap(er) co2 option

ive taken a 5 gallon bucket, added mesh about 20cm up, cut out a whole big enough for a power cord and a small air pump hose, im sticking 2 gallons of water and the appropriate amounts of yeast and sugar in the bucket, an air pump sits on the mesh about 7cm above the water with the power plugged into a timer set for 3 15 minute periods a day (during which my fans turn off), the air hose loops around my plants and i poked holes in it every few inches to release co2, just seein if anyones ever done this before ? its very inexpensive

without a co2 ppm test its unclear how effective this is. couldnt hurt though

Yes and it works fine. You have to do a little math to determine how much sugar/yeast you need for your space - for example: a pound of sugar/yeast will produce ~ 1/2 lb of CO2 - LxWxHx .0015 (1500ppm) assuming no ventilation fans on. My vent fans turn over the room air volume about 6x per hour (once every 10 minutes) so I needed 4 gallons to achieve roughly 1500 ppm. Hope that helps.

edit: you don't really need a pump if you seal the system, the CO2 generated will create pressure so if the only way out is your delivery tubing, it'll "pump" itself.

edit: guess it would help if I gave you something to convert... 1cuft of CO2 = 8.741 lbs of CO2 measured at 1 atmosphere, 70 degrees F