Carbon filter has gone down ,now this is wellshitty because i'm growing ablueberry st

Any idea's on getting rid of the smell.i have a carbon filter the large one think it's the 10" kind.can't mend the fan so have used the exsisting hole in the growroom ceiling.this is where the filter used to be could any one give me any advice on how to get away with makeing a homemade carbon filter.come on guys i'm growing blueberry and it was put to flower yesterday but it smells so strong.help please