21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack double-ended Apply directly to actively growing

Apply directly to actively growing weeds during warm

• Reduces transplant shock

It is a replacement electrode for the GroChek series "-5" models: HI9813-5 & HI9813-5N

the AutoPot FlexiTank can be stored away when not used

Taped seams help keep contaminants out for added protection

21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack double-ended Apply directly to actively growingNordic Pure Custom MERV 13 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