Carbon filter and vent holes

Hi 1st time grower indoor I've started to run my carbon filter and not too sure how many vent holes to open I currently have a small one at top and bottom open no smell but when I close vent tent sucks in will it still get air in with vents closed.. fan on filter outside tent.. thanks in advance

If you don't have a vent open no air can flow, you need at least one open.

Bigger/more vents let more air flow through the tent for cooling and humidity.