The WaterFarm Circulating Upgrade Kit contains everything needed to reconfigure your Hydroponic garden systems to add nutrient circulation capability. What will this do for you? Promote plant growth consistency and improved health. The added circulation keeps the nutrients balanced throughout your WaterFarm 8-Pack system. In turn, you'll see more stable pH levels and the increased oxygenation that plants thrive on. The constant water movement also prevents sediment build-up for healthier plant roots.