Odours can sometimes accumulate with hydroponic growing, especially with a large number of plants and poor extraction rates. We supply ONA blocks, sprays, and gels designed to mask and eliminate these odours. The blocks evaporate over time, at a rate dependent on how much surface area is exposed. This means that you can decide how much odour control you want depending on your systems needs. For larger areas, take the whole lid off, and place the block near a vent or entry way for maximum odor control. For smaller areas you can drill a few holes in the lid and for very small areas unscrew the lid, and leave it only slightly ajar for the slowest rate of evaporation and odor control. Sprays can be used to remove odors on clothing, or sprayed in the air as you leave a grow room to prevent carrying the scent with you away from the area.