CO2 help..

hello ive just started my first grow and all is going well so far.. I have just found a CO2 tank and regulator in my shed and I don't really know how to use it, like how to regulate the amount going in or how much to use, does anyone know how to hook it up and gauge how much is releasing? Any help would be greatly appreciated, heres some pics thanks for your help

I dont know much about co2 bottles etc but I am pretty sure you will need a bubble counter as well. this will regulate how much exactly your releasing into your grow space.

Oh and some sort of timing valve thingy. I think anyway.

In the second pic is the little clear plastic cylinder a bubbler counter? I don't really know for sure but was maybe thinking putting water in there and then it would bubble through it? How would you gauge how much is being released with that?

Not sure as I have never used it before. But if you search "I Grow Chronic" on youtube that guy builds a veg and a flower room. the flower room has co2. I really didnt pay much attention to that bit but he sets the whole thing up and shows you what I would think to be a good setup.
as for adjusting. Not sure I think he brushes on that subject.
sorry I couldnt open the pics before so couldnt get a clear look but could this time round. yeah that is a bubble counter and you also have the solenoid. you need to hook that into a timer. but as he says on youtube only run the gas when your ventilation is turned off.