8_1/2x30x1 Exact MERV 13 AC Furnace Filters 6 Pack nutrients and supplements These highly porous large stones

These highly porous large stones are lightweight

Manufactured specifically for pH and ORP electrodes

COMPOST TEA - 1 cup Insect Frass per 50 gallons of tea - add ½ dose at beginning of brew

It is quiet

8_1/2x30x1 Exact MERV 13 AC Furnace Filters 6 Pack nutrients and supplements These highly porous large stonesNordic Pure MERV 13 Pleated AC Furnace Air Filters provide exceptional filtration for both home and commercial environments. Each time air passes through a Nordic Pure pleated furnace air filter, lint, dust, pollen, bacteria, pet dander, dust mites, mold spores, smoke particles, virus carriers, coughs and sneezes, smog, allergens and other contaminants are removed. MERV 13 furnace filters are comparable to HVAC filters with the rating of MPR 2200