I don’t work for NASA

I assumed you didn’t have to be a rocket scientist, but I’m struggling. Prepare for a ramble.

I have no clue how to properly ventilate a tent or create negative pressure. I’ve watched videos and I still can’t comprehend it. Perhaps I am over thinking it…

I bought a 4x4 ac infinity tent and I have a hlg 600 rspec on the way. Since I have no clue what I’m doing, I bought the wrong fan. I bought the ac infinity raxial S6, which now I know is only a booster fan. Freaking idiot :roll_eyes:

I plan to ventilate in the same room (large space that stays cool 600 sq ft). I do not need a carbon filter, smell is not an issue. I can not figure out how many fans I need, what type of fans, do I even need ducting, and what darn vent hole they go in?

Can someone help a lady out?


Have the fan suck the air out of the tent. Get some 6inch( or whatever size fan you bought) ducting and hook it up it will suck the air from the tent outside of the tent and draw new air in it. Creating negative pressure(sides of the tent will suck in) ezpz lemon squeezey


Exactly what Diesel said.


I do recommend a 6 inch exhaust fan with variable speed will work nice in your 4 x 4 space.


Looks like this in tent at top. Just eliminate carbon filter if you wish.

Open vents on the bottom of tent to allow air to enter tent at bottom and exhust air at top.


Thanks, pictures help a lot. That would go in the hole in the roof of the tent, correct? Not the side?

I should send the infinity 6in booster fan back and get the infinity inline fan like this?

I would install fan inside tent and would need 6in duct to vent out of tent?

Maybe I need to return to this after the indica high wears off. I feel I’m to smart to not be able to comprehend this. Every tent set up looks waaayy different to me, so it’s hard to follow

Edit: Ha! I forgot to post the link lol :joy:



You can put it there. You can put it anywhere really. Depends on what you need. A big rule of grow tent/room ventilation is that your incoming air be oppositional of your exiting air. Example would be these two pictures

Air intake, even though the hose runs into the tent it must still come in at the floor level. And the air vent out at the top on the opposite side of the intake

In order to create negative pressure you will want the air leaving the tent to be moving faster then the air coming in. You can achieve this by making sure there is no opening for the air to come into the tent that is larger then the diameter of your fan. This makes it so that the air cannot escape the tent because more air than can escape the tent is being pulled through the filter. Once achieved the sides of your tent will suck in. I use 2 fans, one in and one out. My intake fan runs at 70% while my vent fan runs at 100% this creates negative pressure. You can achieve the same with one fan by reducing the size of the inrake at the bottom

To less than the size of the fan your useing. In your case, 6 inches) t6 right?


You can exhust top or top side vents, just depends on logistics. I go out the side top due to tent height is too close to the celing.


Yes! And you should also get the controller 67 that comes with it

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I don’t use a controller and find the idea a bit ridiculous. Plants need a steady supply of fresh air and proper input and exhaust help that happen.

I run an AC Infinity S8 (an 8" fan) for exhaust near the top of the tent and I have an AC Infinity 6" (S6) pushing air in near the bottom of the tent. It works great. I run both fans at about 50% constantly.

If smell isn’t a concern I wouldn’t bother with a carbon filter.


Ridiculous? Automation not only helps you to keep the environment stable, but helps you to control the cost of growing. We put lights on a timer because its important that they only run so many hours a day. Fans on a controller allow you to only run them when they need run. Having a triggered controller helps you to mitigate disaster should something stop doing its job, on top of maintaining your desired environment. Im not sure what daily life looks like to you but for me, automation, automation, automation. Its cool you can hover and maintain or wherever you live has an environment that doesn’t require alot of attention from you but to call something silly because YOU don’t need or want it is kinda well, ridiculous.

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We all have opinions. You have yours and I have mine. I respect yours. I’ll leave it at that. Have a nice day.


I find the fancy stuff a bit extra for my taste as well. I bought the infinity cloud series tent, but I was NOT spending the extra money for the digital panel.

There is a nice window where I can see my thermometer and hydrometer. Just me tho

Thanks for telling me what fans I need and where to put them.


The raxial fans work fine, unless you’re struggling to keep the tent below 83f.

You don’t need the sides of your tent sucking in. An exchange of the cubic volume of the tent every 3-5 minutes is way more than enough fresh air for the plants.

That being said, it’s hard to imagine not using a carbon filter in an unsealed environment.


The controller that comes with the T series fans is not the controller 67. You cannot program the included controller to a minimum speed . . . you can the controller 67, but it is a $50 upgrade.

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I’m also a believer that you don’t need controller and cloudline S series will work just fine.

I also agree that will you get negative pressure when there’s more air coming out of your tent than going in. But you can indeed run a larger passive intake than size of your fan is exhausting. In fact, most would recommend this for active exhaust with passive intake.

You can try without carbon filter, but most of us are probably going to say you’ll want a filter by 2-3 weeks into flower. Your house and most of the stuff in it will smell like weed.


Yup. Carbon filters are a big yesyes. Cuz if you don’t run one and you have some really good weed you’ll open your tent and your eyes will water with how pungent they are. Which isn’t a bad thing. But you’ll reek of weed everywhere u go. Like not even like you smokes like fresh flower.


I currently have the raxial pushing air out of the tent and the sides are sucked in. Temps are 79-81 during the day. I have a bloomspect 2000 led (356 actual watts) in the tent now.
I am concerned once I put the hlg 600 rspec in the tent my temps will go up, so I am trying my best to plan ahead

I was unaware it could smell that strong :grimacing:

My last 2 grows was in a shed with a window a/c and the smell was tolerable until 2-3 weeks before harvest.

Can I go ahead and install the carbon filter, but not use it until I need it OR is it better to keep it out of the tent until I need it?