Reddit mentions of VenTech IF6 6" Inline Duct Fan 440 CFM

A speed controller wouldn't really work for that duct booster. It's technically a duct booster and no where near the power of an actual inline fan. So it can be argued that duct booster you linked won't be strong enough to pull through a carbon filter and exhaust the heat in a timely manner. But going by the math and accounting for the carbon filter resistance you'll be able to change the air at the rate needed.

Temperatures is a different story though. As I don't know what the ambient temps run or how hot those mars leds run you're better off just getting http://www.amazon.com/VenTech-IF6-Inline-Duct-Fan/dp/B004YXDQZU/ref=sr_1_1?s=industrial&ie=UTF8&qid=1457749739&sr=1-1&keywords=ventech+inline+fan and a fan speed controller and turn that down. It's better to get a stronger fan and turn it down rather than to get a low CFM fan find yourself unable to manage the temps and need something stronger.

As far as the tent is concerned those cheapo tents tend to be a big hit or miss when it comes to light leak and construction. But it looks as if most of the people on here have cheapo tents with no problems. Nothing a bit of duck tape can't solve ^_^

Had some fun with LST the other day and can't wait to work on the plants some more. I really love how quickly the plants bounce back from the training. I included some more details in the pics regarding what I believe to be a calcium deficiency. Plants were fed with 1/4 strength nutes for the first time last watering. I also sprayed both plants with neem oil as a preventative measure last night.

INFO

Plants: (1) Feminized Barney's Farm Vanilla Kush & (1) Feminized DNA Genetics Tangilope.

Tent: 3'x3'x6' Apollo Tent

Light: iPower 600w closed hood currently running at 100% power 15" away.

Fan: 440CFM exhaust fan

Carbon Scrubber: 6"x16" phresh filter

Soil: 3/4 roots organics & 1/4 big & chunky perlite

Nutes: General Organics GO Box 1 feeding of 1/4 strength calmag and grow veg last watering

Pots: RR > solo cup > 2gal smart pot (currently) > 7gal smart pot

Normal fans do not move enough air and cannot handle static pressure well.

I used this one before upgrading to my Vortex S-Line and still use it to scrub my room during Harvest

Here you go. Don't ask why it has a leather jacket, maybe it's in a gang?

Funny, I'm sitting here drawing a diagram to upgrade my ventilation right now.

Temps are consistently between 72-78 as long as ambient stays around 70. Keeping ambient low is the trick, unless you can pull air from outside or vent outside, which is what I'm trying to work out right now.

I've got one of these on full blast pulling air from the upper part of the veg tent and venting through an HID hood in the flower tent. I have a cheap duct booster for intake. Right now it just vents to the 400sq ft room the tents are in. I'll add some pics in a few.

You want a centrifugal or a "mixed flow" fan, with the latter being supposedly quieter. I just ordered one of these to replace my pair of cheapo axial fans: Can Max Mixed Flow 6" 334cfm

None of these fans are silent by any means. The cheap axial fans are the loudest in my experience.

Paired with a speed controller, carbon filter and insulated ducting, the centrifugal fan cooling my lights is fairly bearable.

Fan $74:

http://www.amazon.com/gp/product/B004YXDQZU/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Fan speed controller $21:

http://www.amazon.com/gp/product/B00EVYGPJQ/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Ducting, $16:

http://www.amazon.com/gp/product/B00DCES1TI/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

Bowl that I used for a hood, $24:

http://www.amazon.com/gp/product/B00KYR0ZF4/ref=oh_aui_detailpage_o04_s01?ie=UTF8&psc=1

Plus various bits of Home Depot screws, chains, eyelets, hose clamps and a stainless toilet flange to connect the bowl to the duct.

530 cfm $90
440 cfm $73
Just search inline fan