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Which size CFM carbon filter do I need?

eddieo

New Member
Hey smokers!
I'm currently on my first grow here are a few details about my indoor grow.
*Grow tent 60x60x160
*intake fan 5" 280m3/hr
*exhaust fan 5" 380m3/hr
*400W hps/mh bulb
*Hydroponics DWC
*OG Kush ONE Plant

The grow is about 6 weeks, going good so far been growing without a carbon filter until now.
The smell is really starting to get strong and it's escaping into other parts of the house and i thought It's time I install a carbon filter.
I have a carbon filter that came with an old tent it's 5" 250m3/hr personally I think I will need a filter that moves more air but please let me know what you think below.
I'm looking to purchase the perfect carbon filter for my tent and fans I need to know what m3/hr (cfm) I need the filter to be.
The temps in the tent now without the filter, vary between 24-29 degrees celsius and on average 26
Last time I was using the filter the tent kind of blew out instead of sucking in and temps were around 32-37 so i took it out straight away. I was also using a 4" ducting hose instead of a 5" which I use now so those things possibly caused the overheating

So basically I'm wandering which size m3/hr (cfm) carbon filter shall I buy, or shall I even try to install my old 250m3/hr filter? Also if you have any other suggestions on how to improve the grow tent please feel free to post below, all sorts of feedback is appreciated.
In addition if you need any more details please ask below.

Thanks growers :ganjamon:
 

Ricky Bobby

New Member
If you are running your 380m/h fan full blast and you slap that 250 filter on there it is going to limit/choke the fan. If that is enough air moving to keep Ur room in check then it would be fine. If not then you need a filter that is rated for the 380 that your fan can move.

I'm not sure if it hard on the fan or not. I've read people saying both sides of that argument.

You could put it on and monitor room temp and rh and make sure u have enough air flowing and see from there
 

Ricky Bobby

New Member
Also you would need to dial back the intake fan to be less than the exhaust. You will have the problem you did before and the smell will leak out. Need negative pressure in the tent. Are you handy with tools? Making a carbon scrubber is pretty easy. I made one that's way bigger than I needed so that I wouldnt need to touch it for a long time once set up and I can get a 5x stronger fan before it's going to restrict air flow
 

eddieo

New Member
Thanks for the reply Ricky
What do you mean by dial back the intake? My intakes 280 and exhaust 380, the tent when closed is nicely sucked in and temps are fine.
But yeah im quite a DIY person but I'm mostly thinking about quality more than anything. I know that if I buy a filter with the appropriate cfm it will be much more reliable than if I just made one without any sort of guide or anything.
How would I make one anyway? would I just put the carbon cloth over the exhaust hose?
 

Ricky Bobby

New Member
Yes with zero restrictions on your outtake and the current configuration it should have good negative pressure in the tent, meaning that more air is being removed from the tent than is being forced in.

Now if you put that 250 m/h filter on there it will be opposite. You would need to put a speed control on the intake or remove the intake all together and just use passive intakes.

The carbon filter I made is amazing. I hate to point anyone to a different forum but there is an amazing write up for an amazing home made carbon scrubber that I can't recommend highly enough. If you Google homemade carbon scrubber. There is a thread on I c m a g by Durban poison, the second or third result from Google, it's fairly simple to make and works 100% effective. I made a 15" long one that could be used for farfar larger area than what I have
 

eddieo

New Member
I understand now thanks.
That guide you recommended is excellent but you couldn't really tell how much cfm it could really take if you just make it no? It would be exciting to try to make it but this is only my first grow so I think just buying one that can handle 380m3/hr or more is a saved option for me at this point, I'll have a look online for some. Do you know any good brands of filters that are fairly cheap in price?
 

Ricky Bobby

New Member
They have a table of size to cfm on there and I think it would just have to be converted to m/h if u wanted to use it in the future. But the reason I made it is when the carbon is shot I can empty it and refil for like ten bucks or so instead of buying a whole new hundred dollar filter or whatever they cost. Sorry can't much help you in that question though. Phresh filters I think was a recommendation when i doing research.
 
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