Charcoal filter hanging from top or on floor?


I was wondering if there were any downsides to putting the filter on the floor of the tent. Off the floor a tad, electricity and all. right now it is hanging from the top, horizontal. I could use the head room.



Anyway works as long as you got air flowing the way you you need it. Mainly just having the intake & exhaust in the right place. My filters on my wall


Heat rises. Top is best.


I agree with @WickedAle. It regulates the temperatures better if it’s on top.


My filter is outside the tent, on the end of the ducting.


Interesting. I was just thinking of dropping mine to the bottom of tent due to height as well (60 inches) between the filter and fan I’m losing a foot of space, the HLG led doesn’t put out any heat to speak of so heat is not an issue but the extra height would be nice to have.


Assuming your filter will be in tent, you want it at top, then bring your intake air in the bottom so there is circulation of cool to warm.


As long as the intake is on bottom and output on top, your golden.

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How’s that working for you?


That’s how I’m doing it now.

Would like that space up top for plant not equip. Since heat is not the issue can’t see a reason why not to move the canister to the bottom.

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@Drillbit Yes, fan is inside hung from the top, intake is on opposite side bottom. I do it this way because in the summer I disconnect the filter and exhaust it outside. In winter I need all the warmth I can get.

@jsanders420 So far it’s worked perfectly.


If you want proper airflow through the tent then the carbon filter needs to be at the top otherwise the air will just circulate around the bottom instead of through the plant.


If airflow is the goal, a 6 inch clip fan or 2 would circulate air just fine. However the filter is to remove odors it also does remove heat (if this a problem) if so you don’t need a filter at all for airflow. My point is for odor control the filter can be placed in the tent top or bottom and it should do its job. Am I missing someyhing??


It circulates air fine, but doesn’t replace co2 consumed by plants.


I wasn’t suggesting the 6" fan instead of the “exhust system” I just see exhust,air replacment and odor control as 2 different things. Though the filter and fan can do both jobs regardless of location as this is “exhust” but will create a negative air pressure and that will draw air in. (Don’t know if negative air pressure alone can draw enough air in to the tent ) if I’m still missing something let me know so I can learn something, sometimes I can be dense (I blame it on old age)

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Odor control is different. The plants will continue to grow whether they stink or not. But they require and use co2, so photosynthesis will slow if it isn’t replenished. In order to have “air replacement” you need some going out and some going in right? So whether you run exhaust fan and passive intake of intake fan and passive exhaust, exhaust is happening. If you need odor control, that really only works one way. But, running clip on or similar moving air around in tent doesn’t guarantee any air exchange. Unless maybe they were positioned as such that one was pulling air in a port and the other is pushing air out. That scenario pretty much becomes an intake fan and exhaust fan, with no separate fans circulating air within the space. Which pretty much takes us back to where I started.

I’ve never tried it, but I’d be willing to bet you could run a pretty successful grow without any circulating fans at all in a small space. If you controlled rh of intake air, had large passive intake in bottom and suitable enough exhaust fan top opposite side.

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I’ve always felt the primary goal of oscillating fans in the tent was help strengthen the stems for upcoming heavy colas, and to prevent moisture buildup within the buds as they form. Secondary was circulation.


I think those are true statements. You could work around both though. Stem strength is relative to what you’re asking plant to hold up, and could be nullified by staking. The moisture could be a little bigger issue depending on how dense your canopy is. If you’re removing the damp air and bringing in very dry air at high rate of exchange, I think you would be alright in some situations. Would likely depend on what was left for pockets in air circuit. Imo it’s not really worth a couple of $7 fans to find out.

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So true :rofl::joy::joy::rofl::joy:

Fans are cheap, a dehumidifier is not

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I agree on the system, just not sure as to the location being important IE top or bottom. When heat issues are not involved at least.The 6 inch fan is used as stated …just to strengthen stems.