16x25x5 (4 3/8) Honeywell/Lennox Replacement MERV 13 Air Filters 4 Pack control system Grow A & B adds

Grow A & B adds an extra layer of protection for the process

It is 8" square and contains over twice the amount of rockwool as the popular Hugo block

This formula has been specially designed speed up absorption rates and can start affecting your plants within a couple of hours after use

has exceeded the range limit

BotryStop WP's competitive exclusion mode of action makes it an ideal rotation partner and a cornerstone of any Integrated Pest Management (IPM) program

16x25x5 (4 3/8) Honeywell/Lennox Replacement MERV 13 Air Filters 4 Pack control system Grow A & B addsImportant Note: Almost ALL furnace filters have a different "actual size" than the nominal size printed on the air conditioner filter. It's best if you measure your air filter for the EXACT size and compare it to our "Actual Size" and then you can be sure your A C air filter fits! With the 4" and 5" air filters there is a wider variance between the nominal and actual size depending on the manufacturer. We also carry 4 7 8 and 5 1 4 inch depth filters,