Home > Support > FAQ > Pump Operation + Maintenance FAQ: Pumps Operation + Maintenance How much can each pump be adjusted using the included controller? There are 10 total speed settings. Each step down from full power reduces the pump’s flow by the following amounts:1000DC Pump – Each step down reduces pump speed by approximately 2.5%1600DC Pump – Each step down reduces pump speed by approximately 2.5%2100DC Pump – Each step down reduces pump speed by approximately 3.5%3200DC Pump – Each step down reduces pump speed by approximately 3.5%