28x36x1 MERV 10 Plus Carbon AC Furnace Filters 6 Pack commercial-greenhouse-fixtures Evening or very cloudy conditions

Evening or very cloudy conditions are the best time to apply

The double Ag/AgCl reference provides less noise (unwanted voltages) than gold or silver electrodes

Inner Dimensions: 1/4''

Leap pH Probe

The Dirty Tan Smart Pot is the best of both worlds

28x36x1 MERV 10 Plus Carbon AC Furnace Filters 6 Pack commercial-greenhouse-fixtures Evening or very cloudy conditionsNordic Pure Custom MERV 10 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition