150 for fan and filter 4 by 4 tent

Looking for a good budget fan and filter for a 4 by 4.
Also does the filter have to be run on the inside or can I put the filter and fan outside the tent I don't have a lot of height in this tent.

You can put the can outside if you want. The ballast too as they get pretty warm.

If you have a air cooled fixture, run them filter>fixture>fan (outside the tent)>exhaust. Get a bigger fan than you might need, you have room to expand & you'll have plenty of airflow. With passive intakes, run your fan high enough to pull your tent walls in a little, insuring you're pulling all the air through the scrubber.
I've read about filters at the end of systems (outside the tent) but never tried. I buy into pulling air through the filter is better than pushing. No expert opinions here, just my $0.o2!

I was thinking a 6inch fan my tent is 4*4*6 so about 100 cf So could possible run it at half power or so. I could go 8 inch I may get a 2 by 2 veg tent if this goes well. So do I need a intake fan too?

IF you use intake fans: keep your tent (s) in negative pressure - make your walls are sucked in a lil bit. If you run too much intake, you'll "blow" smelly stuff out of the tent! You'll need a way of balancing your intake/exhaust. If an 8" is in budget, I'd go that route with a variarc transformer (find them on Amazon). I try to go big on the filter also - I have to be stealthy.

i would highly recommend the Hurricane fan and Phresh filter combo from here:

http://growershouse.com/hurricane-6-inch-435-cfm-fan-phresh-400-carbon-filter-combo

After you add to the cart the price will drop by 10% due to their special discount. You get a quality fan and quality filter. The fan has 5-year warranty and the filter will last you 2-years.

Thanks that looks like a good deal. I have a little hurrican that thing kicks ass