Is another fan necessary?

Grow Space and setup:
Homebox Seconds XL 4.6 x 4.6 x 6.6
5 - 5 Gallon Buckets
1 GH Dual Diaphragm Air Pump
1 - 6"ActiveAqua Air Stone per Bucket
1/4" Vinyl Tubing
FoxFarm Hydroponic Nutrients
FoxFarm Hydroponic Feed Schedule
2 Cool Sun 600w w/Lumatek 120v Ballast
Vortex 6" Centrifugal Fan @ 449 cfm
6" Flexible Aluminum Ducting

With my complete setup that I listed in mind, do I need to add another 6" Votex fan for an intake of fresh air? With the pictures attached (shit quality I know!) you can get a rough idea of what I am working with so far. My fan is pulling air from the grow area, through the lights, over the fan, and out of the top of the tent. I've read mixed opinions on CFM's, creating a negative pull etc and the sides of my tent are bowing in but not extreme enough to warp the support poles or anything. I have a 6" port open at the bottom of the space so that is ensuring some kind of air pull through the grow space. If I were to add another fan it would be to push air in and ensure even distribution. Thanks for your thoughts and opinions ahead of time.

If your temps are good then you are ok. You can always make a lil passive vent at the bottom of your box.. make a lid for it tho as u will want it dark in there if u flower in it.

My tent is close to your dimensions and has openable intake flaps at the bottom. I find the 6 in. exhaust moves plenty of air thru it. The negative pressure is a plus if you are gonna filter your exhaust it will help with the smell

Good luck!

You have a negative pressure issue cut a hole 6" or 2 3" or 3 2" holes and all should be well. Cut them at the lowest level possible as the cool air is on the ground level.

I have the flaps open like you suggested Waggs, and thanks for the suggestions on cutting additional holes in to create more positive pressure woodsmaneh!. The bowing is still happening for now but my next priority is to get a temp/hygrometer for the temp and humidity regulation and control. What do you guys think about this for that prospect: http://inspectusa.com/data-logger-thermometer-185f-hygrometer-0100-dl8835-water-resistant-p-1270.html ? Programmable sampling rate from 1 second to 2 hours would help me project ample times for heating and cooling throughout the day and night times?

I am also going to add a clip-on fan inside of the tent to move more air from the ground up. I think the temps inside of the tent are going to remain optimum at an estimated 60-75 since it stays cool up here for a couple months longer.

Thanks again for your input guys.

the more wind you have coming from the fan the stronger the stems will become due to the stress

nelsonjacob said:

the more wind you have coming from the fan the stronger the stems will become due to the stress

Click to expand...

So should I get the 2nd fan in your opinion to push more air through or do the aforementioned surrounding the vent box or cutting some additional air holes in?

Thanks