Reducing the intrusion of your indoor garden on your indoor life

Indoor gardening is an increasingly popular hobby that allows green-fingered growers to continue producing their own fruit and veg all year round by growing under lights in a controlled environment. Containing this growing environment is essential for maintaining optimal growing conditions and also allows you to minimise the impact of your indoor growing space on your living area. One of the main intrusions that an indoor garden can cause are greenhouse type plant and fertiliser smells wafting around the house. After a while this can become overpowering especially when growing strong smelling plants such as tomatoes or even leafy veg such as cabbage.

Indoor gardeners can remove this problem by installing an odour removing carbon filter to their grow room extraction system that filters the smelly air as it leaves the growing area. For this reason, carbon filters are a very popular addition to most indoor grow rooms – but there is a world of difference between the quality of filters available to buy and some manufacturers claims are dangerously misleading.

Time to put the record straight on carbon filters…

A worrying trend seems to be emerging from some Carbon Filter manufacturers and we think that it is about time that you knew the truth! It seems that virtually every new filter on the market claims to be “lighter” than all of the others and “better” at removing odours because it uses smaller particles of carbon. Watch Out - This is not true.

Let us explain

Carbon is used in a wide range of different industries as an effective medium for filtering impurities from both gases and liquids. The amount and type of carbon required to do the job effectively is determined by what needs filtering. In the case of liquids, smaller particles of carbon are used to provide an increased surface area and greater filtration properties. Depending upon the level of filtration required, there are a range of different grades of activated carbon each designed specifically for the job. Activated carbon for water filtration is very lightweight and packs together very tightly. It is capable of being used for air filtration but will cause a large pressure drop and put undue strain on your extractor fan.

The type of carbon used in air filtration again comes in differing grades dependent upon the level of filtration required. For the complete removal of odours, the depth of carbon used must ensure that there is a contact time of between 0.1 – 0.2 seconds between the air and the carbon. Also, there are specific forms of carbon designed for air filtration. Air filtration carbon is typically formed into small pellets of compressed carbon. This makes it slightly heavier than water filtration carbon, but crucially does not cause large pressure drops when used in conjunction with an extractor fan. The pellets are formed specifically to allow easy airflow between the carbon pellets whilst still providing the required contact time for complete odour removal. Even when fully compacted, air filtration carbon maintains sufficient space between the pellets to allow relatively rapid airflow.

Why should I care?

This information is crucial to every indoor gardener because whilst some manufacturers are claiming that smaller carbon is better at filtration, they are in fact charging a premium for a product that is cheaper for them to make (water filtration carbon is cheaper to buy than air filtration carbon) and is completely inadequate for the job due to the massive pressure loss that these filters cause. They are effectively making the cheapest products possible and then charging the most money they can by claiming false benefits.

What should I be looking for from a good Carbon Filter?

A good carbon filter will be quite easy to spot. It won’t claim to be super light weight, it won’t have above average carbon dust all over the sleeve and inner chamber and there will be no rattling of loose carbon from within the filter. It will use high-grade pelletised air filtration carbon and not cheaper water filtration carbon that is not right for the job.