Correct Ventilation

Hey guys, I had some questions regarding the CFM and ventilation of my grow tent. So here’s my specs:
48x48x80 grow tent
(2) HLG R spec 260 W lights
Growing in soil (4) plants

My ventilation system is this:
4” terrabloom 18 w adjustable inline fan (160 cfm max)
4” terrabloom carbon filter
4” ducting taking air outside of tent. (Venting in same room that tent is in)
1 small fan moving air around inside tent

I guess my question is, is my fan/filter appropriate for my size tent? Also, do I need to have any sort of intake? I keep all openings closed tight except the ducting from my filter/fan. I want to make sure my plants have proper air circulation, and whether or not to upgrade my fan/filter, etc.

I’m finishing up my first grow, the filter seems to eliminate maybe 90% of the smell, there’s still some smell lingering, even with ona gel outside of my tent. My temperature inside the tent has stayed between 70-75 degrees and between 50-60% humidity throughout. My plants have done great except the harvest is looking drastically lower than what I anticipated, I didn’t know if improper airflow could’ve played a role in that. Any help is appreciated, thanks.

Usually recommend a 6" exhaust fan and 6" carbon filter for a 4x4 tent, very surprised that a 4" fan with carbon filter is keeping your temps at 70-75. Don’t need an intake fan, passive intakes usually work just fine at letting enough fresh air in the tent.


Sorry for my lack of knowledge, but is passive intake referring to just leaving a vent hole open in the bottom of the tent to allow air in?

Yes, a lower vent hole or some tents have a square/rectanglular screened off passive intake in the lower back, usually with a cover with velcro that can be removed to open it up. If using a vent hole, best to use some ducting with a turn or 2 in it to keep light out during flowering, also need to be concerned with light getting in if using the screened passive intake.

Im confused on which ventilation option to use on sf1000D tent kit. Just got the kit, first time tent user. Tent will be in a room that has heat and a/c. Thanks for any advice, and i can post the options pic if needed. Couple of the options make no sense to me. And im no dummy ! Haha.

@Hellraiser I posted a question about best of the 3 options with sf1000d kit. Maybe you could chime in !

No insight from any of my usuals?! Setting up tomorrow!

Let’s see the options or what you went with.

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Will send when I get home from work. Its the sf1000d kit. Low end yes, but good to get me rolling. Just came out of po box and picked up my eggs from ilgm!! Things coming together! Thanks and ill reach out this pm. Fem photo mango kush is my startup by the way. Been 28 yrs so im basically starting over.

If it’s like the 2000 kit there’s 3 screened vents at the bottom. I use the backside one, against a wall. Have some black fabric laying over the top against wall to make sure no light gets in. I’m sure the 1000 is the same besides being half as wide.

Heres the options in the paperwork?

@Hellraiser @Budz @ConcreteBudz

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I will be setting mine up on the outside of my tent there for to give me more room to raise my light up ETC my light maxes out my tent is like 2inches shorter so I need the extra space.

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I would go with the first (preferred method) or the second - filter inside, fan outside. Whichever is easier for you to do. I do both - my veg tent is like the preferred method but with no carbon filter (just fan in the tent) and my flowering tent is done with the 2nd method to have more room for lights and space above them, so just carbon filter in the tent and my exhaust fan outside the tent - on top of the tent.


Extension cord with receptacle strip inside I guess? Where is best place to run cord into tent? Assembly today after work!

There is usually an access hole/port made for that in most grow tents, look for something like what I circled

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tent closed, dark hours, vent fan on low, sucking in sides of tent, but not really a solid source for fresh air to get in ?

You do need to provide a way for air to easily enter the tent, prop open that screened passive intake to let air in and your tent sides won’t suck in so much. Make sure it doesn’t let stray light in when you hit flowering though.

Did that last night. Golden. Live having a tent, and already wanting a bigger one! In due time. Want to let the female i have run its course before I hatch new eggs. Or, i would need a second tent!:hear_no_evil: this one worthy of moving on with i think

rice AND silicate bed for new eggs!! Thanks for your continued support @Hellraiser. And rest of you!