Complete Hydroponic system DWC Grow kit #3-4 by H2OtoGro Made with 100% Food Grade Polyethylene! Deep Water Culture ~ The roots are suspended in the reservoir beneath the net pot(s). The roots bathe in nutrient-rich solution throughout the entire grow cycle.; which increases yield and reduces grow time. Water level indicator ~ Helps maintain the proper water level in the reservoir without lifting or removing the lid. The blue color helps inhibit algae growth. DOES NOT INCLUDE PUMPS. (See our Bubblers & Top Feed for items with pumps)