Carbon filter - How oversized can I go?

[sleepingdrago]

Hi everyone. New member here who is also new to gardening let alone indoor gardening. With great hope and excitement, I'll be able to throw some seeds into some coco coir that I've been purchasing from Attitude. I might have gotten a little overboard on selection, but there was giddyness in having bought seeds of jillybean, white rhino, bay 11, og kush, florida og, and a whole bunch of freebies. I've gradually bought the setup, with just a few more things to go.

My main point. I have a blauberg 4" which pulls 105 cfm on high. I bought a 200 cfm Phresh carbon filter without doing much thought into it. I have a few growing books, one of which by Mr. Cervantes in his Cannabis Encyclopedia and he states to have the cfm of the carbon filter to be no greater than 30% of the fan that's pulling from it or else airflow will be restricted. Anybody have any thoughts on this?

 

[pooloss]

Your carbon filter will be fine. Ideally the slower the air moves through the carbon filter the better.

 

[sleepingdrago]

Hey thanks for the info pooloss. What about the fan itself? Does it work harder from the pressure/resistance from the filter?

 

[pooloss]

I doubt the fan would notice it. I'd keep a spare. I have a two spare fans in my grow room, just in case.

 

[sleepingdrago]

Thanks again pooloss. Youre probably right about the fan not noticing. Im only going to have a grow space of 3x3x6, so if worse comes to worse I can use passive intake instead of forced, which is what I orginally want.

 

[pooloss]

It's about the smell really. Ideally you want negative pressure in your grow space. If my fan failed the smell would leach out in to other buildings and I'd be in the shit, hence backup fans. I even have a backup filter.

 

[OldSchool 64]

Bigger the better..and if you can afford it buy a mountain air filter....the cheap ones are crap when flowering starts..
Most people usually buy a few till they get a real filter..
So anyone thinking of a filter..get the best.
Your life might just depend on it. ..lol

 

[pooloss]

^^ Agreed!

 

[sleepingdrago]

OldSchool64 - Mountain air carbon filter was not available from Amazon or the hydro online shop I shop at (growershouse.com). However, i did read somewhere that Phresh and Mountain air use the same RC-48 activated carbon, which apparently is the best type of carbon for odor removal. Everyone else, not so good.

Pooloss - If the outake fan is creating negative pressure, then that should mean the passive intake should not leak air since there is negative pressure created from the outake fan. At least that is how I understand it.

Really appreciate everyones opinion and input!!

 

[pooloss]

Correct. You want air being sucked in to the room and then out via the carbon filter. No smell.