13x23x1 MERV 13 AC Furnace Filters 6 Pack Tubing Prior to that leaving them

Prior to that leaving them high so the plant can stretch into them is ideal

allowing you to operate the ballast outside of your grow room

Duct Size: 8” | Dimensions: 8

Calibration of pH can be with 2 or 3 points

Suitable for cleaning equipment and tools

13x23x1 MERV 13 AC Furnace Filters 6 Pack Tubing Prior to that leaving themNordic 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