Cultiwool will provide the substrate with a donut ring as well
Nordic Pure 10x20x1 MERV 10 Plus Carbon air filters are made of a dual material where the MERV rated material has been fused together with a carbon layer
MERV 8 furnace filters are comparable to HVAC filters with the rating of MPR 800
Auto-prunes roots & prevents root circling
NO dissolved mineral salts
20x20x1 Pleated MERV 14 Air Filters 6 Pack MH Cultiwool will provide the substrateNordic Pure MERV 14 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 14 furnace filters are comparable to HVAC filters with the rating of MPR 2800.