Complete Hydroponic system DWC #4St-6 H2OtoGro IT'S BACK!!! One of our most popular systems is available again! Get yours now.... 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. Made with 100% Food Grade Polyethylene! Grow herbs, flowers, fruits and vegetables anywhereindoors, outdoors, counter top, office, tight spaces, etc. Deep Water Culture ~ The roots are suspended in the reservoir beneath the net pot(s). The roots bathe in an oxygenated, nutrient-rich solution throughout the entire grow cycle.; which increases yield and reduces grow time.