Hello all,
Can anyone recommend a good carbon filter that would take care of the smell produced by 3 plants?
Plants are in a grow tent which is located in the basement. The tent is 8’x4’, I am hoping to setup the filter in a way that doesn’t require the airflow to be sent outside. Is that possible? If, I need 2 filters, so be it.
FYI
I am currently installing duct work to circulate the air with the outside but that won’t be ready until the next grow.
Thanks for your help
Yes. You can vent it back into the same room. Some people have heat problems though, since you are taking the warm air from the top of the tent and putting it back in the room.
The best filters I have bought have come from Phresh or AC Infinity.
Do u have somewhere else to vent To? I vent mine to basement. For that space, maybe 2 - 6" carbon filters. But, wait for the pros to come on and give their recommendations. I once vented an air conditioner between my walls. probably not a good idea. good luck.
Thanks for the replies.
Even though this is all aboveboard (I have the cultivation card), I am still a little worried the about the smell getting on the kid’s clothes.
Thanks
Hi @kirstee I have only used three different brands including the one I use “G Hydro” but there’s probably a bunch more out there that are good. I’ve used I-power and vivosun and the G is better at cleaning up the smell. So personally I would go with two ac infinity 6" fans and buy them in a kit with a filter then if I wasn’t satisfied with the filter I would go back to the G Hydro
Terrabloom , Offers a quality carbon filter in a
6"x 24" an also phresh. I have personally used both filters. Either one will get the job done, both about same price. 
sry, i dont use the filters. i just push my exhaust thru my dryer vent outside.
I have used the 6x16 filter in a 4 x 4 space and done a fine job.
I actually thought about this but it’s against code here.
Did you just filter the air to the outside of the tent? Would you recommend running 2 of them? Basically, I don’t want visitors saying they smell it.
Yes, I filter air before exhausting outside .I think one filter will be fine. I live in a unfriendly state and smell Must be taken care of even if exhausted outside. The 6x16 Maximum space would be 5x5
100% understood. some dont have that option. luckily for me i live where its all legal. as for codes on the vent. again i own my home so unless im looking to sell my house i have no need for inspections. go canada go. lol
Good thread. I need a suggestion myself. PERFORMANCE over price. Bought cheap before. Just threw away an 8" that was a complete waste. I do not care cost…just want top end performance.
To calculate the ideal amount of airflow you need, a rule of thumb is to choose a duct fan with a CFM greater than or equal to the cubic feet of the area you are venting.
So: L x W x H (in feet) of your tent = N cuft. Then you need to look for the appropriate size fan which moves that much air. My guess is 8 or 10”.
Ducting it outside is definitely ideal, I’d try to figure that out sooner than later. Mine goes out the basement window:
I vent out top into room. Portable ac to turn on if needed. 3 tents run in sequence. Last tent 8" carbon and exhaust fan. Dimmable. Pulls well all the way down the line. All push from top and in from bottom vents. Now that it is winter working great. Summer that 10kbtu portable does great on low. Good filter and room will clear a cigarette almost as fast as i burn it.
I have a 4x4 tent with 6” AC Infinity fan and vent back into the same room. One carbon filter is sufficient to eliminate the odor. One should be sufficient for any sized tent, it may just get “used up” faster and no longer control odor the more odor molecules you pass through it. As the pores in the activated carbon start to get filled it slowly becomes less effective. Just a hint at first. That’s your cue to get a replacement.
I find that venting in the same room is a perpetual struggle to manage heat. A dehumidifier in the room controls humidity just fine, but heat is a constant challenge. I have a second 6” fan that directs room air into the HVAC return duct, and it works well when set at the right speed. Let it get warmer out or the wind change direction and it’s 77 in the bedroom. I can’t just crank the return fan on high all the time because it roars (cheap fan). A better fan or an auto controller would probably solve the problem, but I only need to get to spring. Once the weather warms I’ll be dumping the exhaust outside.
Here’s another tip for the filter, and it’s a critical one. If you need to run a humidifier in the tent, you must use RO/DI water. Otherwise your filter gets plugged up fast.
I’ve got pretty clean tap water (115 ppm TDS) so I thought I could skip this step. I was wrong.
I think one of your questions is what size fan do you need and a filter to pair with it. AC Infinity, being the a quality supplier, helps answer this question. It has a good article in its technical - guides / grow tent ventilation guide as to how to size the fan to the space. Give it a read, I think it provides good basic info.
I am assuming your tent is 7’ tall
Cubic feet of tent: 8x4x7 = 224
The article says the resistance caused by the filter and ducting needs to be accounted for.
It uses a 60% factor for a filter and another 20% for ducting
224 x 1.6 = 358 x 1.2 = 430 CFM . Wait we need to allow for heat generated by lights. That adds another 50%
430 x 1.5 = 645 CFM minimum requirement.
I think two 6" fans at around 400CFM per fan would be just about right. Can’t go wrong with AC Cloudline fans. I have two S6 models (manual controller). I have one AC filter and also a terra bloom filter. They are both good filters.
S6 and terra bloom for exhaust
S6 and infinity filter for intake
Thank you for your insight. You answered all my questions including a few that I hadn’t thought of.
Thanks again.
