Need advice on air intake and venting.!


First timer here, this is where im at so far have 3 tent grow systems I have 1 4’x4’x80" that I use for my mother plants and seedlings the other 2 4’x8’x80" 1 has 2 250W led on a 18 hour grow cycle the other has 2 300W led lights on a 12 hour bud cycle.! I purchased a 6" heavy duty exhaust fan with the round flex silver hose and a huge charcoal filter,! I use my basement for my grow room and one of the windows is under my front porch I used a piece of plywood to cover the space after I removed the window and use it for a fresh air intake.! I put the three cool grow tent in a row and place the fanin the end bud tent on the floor all the exhaust holes line up perfectly I ran the intake hose intothe top hole of the tent and sinched the draw strings tight,! my problems are two fold,! first the fan has no speed control so the middle grow tent is getting way to much air although it is making my stocks huge it still seems like too much air also I don’t know how or where I should put the filter,? I saw an article where the units were used at the top inside of the tents.! can anyone explain the best way to run this filtration system.?

I am sorry the top of this question is not mine the 3 rent ventilation help section is where my main concern is.! Also the led lights are 2500W and 3000W.! I am growing super skunk and golden leaf.! How many plants should this 4’X8’X80" tent accommodate.!

Also I ordered some auto flowers for my next crop how does growing them differ from the way I am growing now.? How many hours of light do they need and does the time stay the same throughout the entire process.?