20x25x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 2 Pack Terp Derp Cultilene Blocks have an optimum

Cultilene Blocks have an optimum air/water ratio for healthy root growth and allow for great continued rooting thanks to the extremely even distribution of water and EC

Here’s a convenient three-pack: Big Bloom

And understand that once it has dried out it can take time to become saturated again

Torched is tough on broadleaf weeds and grasses while being gentle on your conscience

Bluelab PeriPod M4™ will maintain stable pH and nutrient levels in your reservoir

20x25x4 (3 5/8) Furnace Air Filters MERV 8 Pleated Plus Carbon 2 Pack Terp Derp Cultilene Blocks have an optimumImportant 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. If you are replacing a 4 3 8 depth 20x25x4 filter