I total understand budget. Anything you want to do at the end of the day is fine by me. No worries at all. I’m trying to possibly give ideas / options to think about.
On the Co2 same tank and reg setup like your planning. The black line runs inside the tent.
Then I T’d the line and dropped the Co2 where I want it. You only need to drop 1 line but you could drop more if you want. The fans will move it around.
Talking about Co2 safety / waste. When your exhaust fan turn off you want to disable Co2 injection if possible.
My controller is setup with this Dcc that tells my Co2 not to turn on if exhausting is on.
Last thing you want is 50lb of Co2 exhausted into your attic/house.