20x20x4 (3 5/8) Pure Carbon Pleated Odor Reduction Merv 8 Furnace Filter 1 Pack Water Filtration Bloom A uses patented technology

Bloom A uses patented technology specifically designed to optimize phosphorus uptake and protection during the reproductive stage — something most generic bloom formulas don't address

Stem Mildew

000°K - 4

Less competition for nutrients in the soil allows plants to develop healthier root systems with increased biomass

20x20x4 (3 5/8) Pure Carbon Pleated Odor Reduction Merv 8 Furnace Filter 1 Pack Water Filtration Bloom A uses patented technologyImportant Note: Almost ALL furnace filters have a different "actual size" than the nominal size printed on the air conditioner filter. It's best if you measure your air filter for the EXACT size and compare it to our "Actual Size" and then you can be sure your A C air filter fits! With the 4" and 5" air filters there is a wider variance between the nominal and actual size depending on the manufacturer. If you are replacing a 4 3 8 depth 20x20x4 filter