That flow rate is dependant on the diameter of the piping you use. Using a Barrow flow meter my D5 pump (with 10mm diameter hose) produces (litres/min) at the following power outputs 100% = 6.8, 90% = 6.5, 80% = 5.5, 70% = 4.5, 60% = 3.5, 50% = 2.5, 40% = 1.3 and 30% = 0.2. I have a 2 x 360mm...