Odour control

Odour control beyond the carbon filter

A well-sized carbon filter deals with the air leaving your tent through the extraction run — it does nothing for the smell that escapes when you open the zip, or that clings to a grow room outside the filtered chain. That's the gap ONA products fill. ONA Gel comes in 426g tubs (£9.45) for a single room, 3.8kg (£42.95) for a whole grow room, and 20kg (£154.95) for anything commercial — the gel neutralises odour molecules rather than masking them with fragrance.

For a lighter touch, ONA Spray (250ml) and ONA Blocks (170g) suit smaller spaces or topping up between gel changes. A Grow Gadgets Ozone Generator (£29.95) is a stronger option for an empty room between grows — never run ozone in an occupied space. OCD Deo-Max Aerosol (£8.49) is the quick-fix option for a sudden smell after opening the tent.

Sizing your setup

Match gel size to room size, not tent size — the gel treats the air in the space around your extraction, so a 3.8kg tub for a spare bedroom is usually plenty. If your filter itself is undersized or the carbon is tired, that's a different problem: check our carbon filters range and the fan and filter sizing guide first. Free UK delivery over £60, or call 020 3488 0419 for advice on odour control for your specific room.