400w hps cab grow

okay i've posted this a couple times ((different things though lol)) but my area is 3x3x4 or 5 foot. i have an 400w hps, spinning fan, 80cfm inline fan for exhaust. this gave me temps of 89F the 80 cfm is now my intake wich i didnt have before and baught a 6in 250 cfm inline fan for my exhaust i'm hopping this well lower the temps my quetion is it seems like when i connect my ducting to my new exhaust is sounds like the fan dies down in power why is this shoot me up ill be back after i catch a buz

bump come on guys heres some picsView attachment 1201406View attachment 1201407View attachment 1201405

when the fan is connected to a long amount of duct it takes a lot of cfm's to push it the distance . So maybe your fan is too weak. mine is like 750 or something like that. Thats probably what it is though, too much distance for the fan to push the air. Thats my 2 cents Im sure you'll get a second opinion.

OKAY EXPLAIN THIS PLEASE so i just turned my spinning fan on the inside off i turned it off and half hour later temps were at 83F. why did the fan make it 89F?????????????

Dont run the intake fan. Try a passive intake with the 6in sucking the air out