DIY CO2 question

So I am going to make a CO2 bottle via Wiimb. My question is how effective it will be and where to hang it? I have a 2x4x7 tent, 600W hps, 4" wind god sucking through a mountain air carbon filter 23/7(I like to smell them in the morning while I get ready). I am 5 weeks in to flower with 5-7 left. The tent is really crowded so I really want to add some 2 liter CO2 bottles. I know the CO2 is heavier than air so hang it above the plants. My questions are with the exhaust fan running will it get to them? Will it help to be close to the tops? Should I put 2 in due to the air exchange? Never done CO2 and not going to get anything fancy for a little tent. Any help is appreciated.

THIS THREAD WILL ANSWER EVERYTHING FOR YOU IT WAS STARTED CAUSE OF MY CO2 EXPERIMENT I WAS DOING BUT HERE IS THE LINK

https://www.rollitup.org/indoor-growing/480336-best-mix-sugar-yeast-water.html

Your exhausts should be off when co2 is running. You need something to time it so the fans shut off when the co2 kicks on every hour or whatever it is, and back on after 20 minutes or something like that. Others would know more about this. I'm just repeating what I've read about co2 over the last fifteen years. I don't have any hands on experience with it.....yet Good luck broski.

Thanks for the quick responses. Timers are irrelevant with the 2 liter bottle system since it steadily supplies the CO2. I will read the thread about on the perfect mix as I was still unsure on the ratios to use anyhow. I wish I could put my 5 gallon carboy of Belgian Tripel in there but it would be below their tops and take up the room of an extra bucket. =>

Here's some other ways
https://www.rollitup.org/general-marijuana-growing/492300-new-co2-generator.html