Hydro Crunch 6 in. x 12 in. Carbon Charcoal Air Filter with Flange 400 CFM Exhaust Scale Multi-ply bag material is designed

Multi-ply bag material is designed to lock air out

scale & mites as labeled

secondary and micronutrients

Membrane Power Flush Kit now included

if the Err4 still appears

Hydro Crunch 6 in. x 12 in. Carbon Charcoal Air Filter with Flange 400 CFM Exhaust Scale Multi-ply bag material is designedHydro Crunch 6 in. Charcoal Carbon Air Filters remove odors safely and naturally. The virgin activated carbon is the key ingredient for removing all odors organic or chemical smoke, plant, pet and cooking odors are all absorbed, trapped and held in the highly activated virgin carbon and the pre filter will catch any dirt or debris allowing the carbon to do its real job. To use attach to a fan for exhausting and you have an instant neutralizing odor