if my room is to dry would this cause my plants to yellow in all new groath and brown on tips of leaves got 400w hps and my intake fan is alot bigger than my out take so i thought might be to dry?????
I would use the bigger fan for the exhaust and the smaller one for intake , As for the yellowing , .Like t man said how far away is your light from canopy , Pics of whole plant would help
it is kinda normal for new growth to be a lighter shade of green
brown tips can be form heat or nute burn
put a bowl of water in ur grow room if you are that worried about humidity