Hydroponic DWC Grow kit ~ # 3 6-site H2OtoGro All H2OtoGro hydroponic systems are manufactured using 100% Food Grade, "Blackout" style, customized reservoirs and lids. 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. Can be used indoors or outdoors. Accessories are available through H2OtoGro Perfect for beginner, seed-starting or cloning. Replacement only - DOES NOT INCLUDE PUMPS. (See our Bubblers & Top Feed for items with pumps)