Plants are wonderful things, we all know that. They grow, they thrive and they produce delicious fruits and heavenly scents. But they can also produce some fairly unpleasant smells sometimes too - they are living things after all! So one way to promote freshness in your grow room is to run regularly extracted air through an ONA Odour Control Duct. All you need do is place one of these units between two sections of ducting and fill the mesh metal internal tube with an opened ONA Block. Any nasty or odorous molecules are then effectively neutralised, restoring the air in your grow room back to being fresh and pleasant. Wave goodbye to nasty niffs and say hello to pleasant smells again, with ONA Odour Control Ducts.