grow tent too hot

ive got a dr60 tent im using it for veg i have an 250w envirolight with reflector trouble is the tempratures reaching 90f what should i geet for ventalation ive got a rvk 150 would that be too big thanx everyone

ventilation my friend ventilation is key

shud i stick my rvk fan on then

don't know if that will all help. In my tent i have a 250cfm inline fan and 400 watt hps with diy air cool design and temps get up to 85 depending on the ambient temp. I live in arizona so it is hot as hell here. My harvest still went well. I read that canna is an adaptable plant and up to mid 80s is okay. I would reccomend getting more intake and a bigger exhaust to get more good air moving in and bad out....

what size fan should i be looking at as its doing my head in