17x28x1 Exact MERV 7 AC Furnace Filters 6 Pack Nutrients and Supplements Electrodes can become dirty from

Electrodes can become dirty from use and will produce inaccurate results even as they read correctly in a pH buffer

Internal battery keeps settings during unexpected power failure

Competitor green CLF "party lights" or incandescent bulbs do not provide the correct spectrum to prevent photosynthesis

ECOMAX is compatible with all soil or soilless growing media and can be applied as a tea

Replace with the traditional lid when you are ready to start fruiting

17x28x1 Exact MERV 7 AC Furnace Filters 6 Pack Nutrients and Supplements Electrodes can become dirty fromNordic Pure MERV 7 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 and other contaminants are removed. MERV 7 furnace filters are comparable to HVAC filters with the rating of MPR 600. While different companies use different scales to measure the air filters