Clean air is essential when you are nurturing plants indoors so your air conditioning system needs to be on top of your climate control. The OptiClimate units have built-in protection through their carbon filters to help you reduce the potential problems of damage and disease to your crops. When there are mould spores in the atmosphere they present a danger to your plants, and the carbon filters take these out of the air to reduce the risk of disease and to eliminate unpleasant smells. You do need to replace them on a regular basis and you can do this with our replacement packs. When the original carbon filters become less effective – you can find out optimum times for changing them from the unit's manual – put a new one in. Replacement packs come with three filters.