Place the 6 inch Square Flood & Drip Shield on the top of a six-inch Rockwool cube. This product can be used in both the vegetative and flowering stages, however we recommend using this unit primarily in the flower stage, and then using the FloraCap throughout the vegetative phase. Eliminates algae and pesticides by covering the media. Built-in overflow where excess water and nutrients are delivered straight to the root ball. BPA and lead-free rubber. Instantly transforms from a top feed to a top-feeding drip system with the Barbed Insert.