4' x 4' x5' Grow tent fan question (quickie)

I have a 3.5' by 3.5' by 5' DIY grow tent set up. Will have a 400w digital from htgsupply with euroreflector.

Looking for advice on ventilation ideas.

With this small a set up, do I really need the 6" high velocity inline fan ($100)(400cfm) or can I just use a couple of 6" inline duct fans (250cfm) for this set up?

Just to make sure I have this right:
Am I having 2 ventillation systems here...one for the cooltube/hps (to just remove hot air) with another at the top of the grow tent with a carbon filter OR can I just pull everything from the cooltube (from inside growtent through cooltube out of grow tent through carbon filter and vented out of room)?

All you will need is a Can-Fan 9000, and a good 4 inch in-line fan. The exhausting of the "dirty" are will be enough to keep the grow tent within 5-10 degree's of ambient out side air.

I would go with a can 33, and a active air 309cfm.
You gota have it dude. You can't get away with no carbonfilter.

Ask any one here.

stupid said:

I would go with a can 33, and a active air 309cfm.
You gota have it dude. You can't get away with no carbonfilter.

Ask any one here.

Click to expand...

I was asking myself about ventilation aswell. I have a 4x4 tent with 400hps and i was looking for a cheaper way to install my ventilation anybody with any advice please get bacc. im new to growing indoors