Odor Control for Indoor Grow Rooms

So your indoor garden stinks? Well, blame it on the girls! On their terpenes! While you might have some odor issues during veg stages, the true stinky giant doesn’t awake until early flower and only gets worse as the buds bulk and ripen.

Terpenes are categorized as volatile organic compounds (VOC):

  • Organic compound: chemicals containing Carbon
  • VolatileOC: organic compounds that readily become vapors/gases under normal conditions.

Escaping through the trichome’s porous membrane, these terpenes evaporate into the environment causing that permeating smelly dank that could blow your indoor garden’s low profile.

Lets explore two popular and efficient methods that have been used to eliminate odors in many  medical marijuana indoor gardens:

  • Carbon filters
  • Odor absorbing gels

Carbon filters:
Depending on use could last anywhere from 9months– to just over 2 years.

  •  Can be used in closed systems– a stand-alone unit that cleans and re-circulates the air.
  •   Can be used in systems with ventilation– usually placed next to the air intake.


How do Carbon filters work?
Carbon filters and inline fans work together to draw in danky air. The previously processed and extremely porous carbon inside the filter is more than ready to partner up with a positively (+) charged candidate. And who do you think makes a suitable match?

You guessed it, stinky terpenes-VOCs! The carbon pulls on the VOCs, filling its porous surface with sites where chemical reactions between the negatively (-) charged Carbon and positively charged (+) VOCs take place.

If chemistry has taught me anything, it’s that if two things in nature ATTRACT one another for the common cause of reaching stability, then you can expect a reaction to take place like clockwork, unless either starting material has been exhausted. In this case, the efficiency of a carbon filter relies on the number of unfilled pores. As the pores become filled overtime with use, the efficiency of the filter becomes unreliable.

Using a pre-filter helps preserve your carbon because many particles are caught in the sleeve before getting to the filter. When your filter no longer works, its time to either refill it or get  a new one. Chances are if you can smell it, so can your neighbors.

Got questions on how to set up your filter and fan? Or which fan is compatible with your particular carbon filter—cubic foot per minute (CFM) ratings?

Here is a YouTube video on how to set your filters.


The following was taken from the FAQs page on Phreshfilter.com: http://www.phreshfilter.com/faq.aspx

Q: Can I put a higher CFM fan than what the filter list?

A: Not recommended, the max CFM is rated on the filters. If you go over this amount it will not give the passing air enough “contact time” with the carbon and the filter will not be able to do its job as effectively. Further, it will diminish the life of your filter.

In short, check the CFM rating on the filter and make sure your fan matches it, or at least ensure it doesn’t go over for the reasons stated above.

Carbon filters can’t be ALL good new,  can they? The biggest downfall of a carbon filter besides price—they are heavy! Have you ever tried to lift one of those things above your head? Talk about #gym420!

What about smaller gardens? Medical cabinets? Stash closets? Or even the trim room where a pile of recently harvested material sits and awaits trimming, stinky trimming. How do you eliminate and deodorize those smells? A quick and cheap fix is odor-absorbing gels.


Odor Absorbing Gels: 
Existing not only in gel, but also liquid and spray format, biodegradable odor eliminating products work great around the garden and house to keep your indoor garden deodorized.

Derived from plant compounds and made with essential oils, the ingredients in these gels either work on masking the issue (deodorizing) or bonding (neutralizing) with VOCs to transform them into an odor free state.  Check out Ona products (stands for odor neutralizing agent) on their website here.

Whatever your choice for odor control may be, as long as you’re nipping the issue in the bud your girls should remain discretely stinky. Hope this has helped, happy growing!