20x20x5 (4 3/8) Honeywell/Lennox Replacement MERV 13 Air Filters 4 Pack X Nutrients Grow Spray 1 Gal Note: For maximum performance

Note: For maximum performance

All RAW Microbes are Double Tested

The premium granules expand up to 7 times in volume when hydrated

BULK should be used in the flowering stage to optimize flower production

This is easily accomplished by simply increasing the Bloom

20x20x5 (4 3/8) Honeywell/Lennox Replacement MERV 13 Air Filters 4 Pack X Nutrients Grow Spray 1 Gal Note: For maximum performanceImportant 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. We also carry 4 7 8 and 5 1 4 inch depth filters,