Black Ops Replacement Pre-Filter 12 in x 39 in Black Rockwool They are 100% water soluble

They are 100% water soluble formulas containing a properly balanced mixture of all essential plant nutrients with quality-enhancing elements

reflects up to 97% of all radiant heat and inhibits the growth of fungi or bacteria

Increases photosynthesis for a greener plant

though those natural levels provide only slight benefits to plants

Incredibly cost effective

Black Ops Replacement Pre-Filter 12 in x 39 in Black Rockwool They are 100% water solubleUse these for a pre filter on you Black OpsNutrients Carbon Filters. Match the pre filter to your Black OpsNutrients Carbon Filter size. Helps to extend the life of your Black OpsNutrients Carbon Filter by keeping dust and other particles out. The black color does not show the dirt as much.