Hey bcurwi1...
The dude is rite, the Carbon Filter is purely to 'clean' the smelly air in your grow room. It also has the benifits of keepin a steady air flow around your chamber, and helps the plant absorb a constant stream of fresh Co2, and also helps keep the tempreture down, by sucking all the hot air out, and dragging in fresh air from outside.
If ya decide that your plants are gettin a wee bit too smelly, and plump for gettin a carbon filter, then you'll need to get a 'through-fan', and plenty of ducting. The fan must be placed outside of your chamber, with 12 or 8 inch ducting connected to either end. One end connects to the filter, inside your chamber, and sucks the air over the carbon, thus chemically 'neutrilising' the ions that make the air smelly. This smelly, hot air is sucked by the fan, and blown out the other end, totally odorless and out of your grow room.
I found my fan was a great value for money item, and depending on how far in to flowering i am, usually hook it up to a timer switch and have it on for 20 mins outa every hour. Maybe more durin summer, to regulate the heat a bit, but still not too leccie thrursty.
I'll put sum pics of my set up, showing the position of the fan and the ducting, along with the filter.....
Take it ......
Ezy
