I am using a Waters 680 gradient controller with 3 Waters 510 pumps. Right now, I am just using Pump C for an isocratic method with solvent system of 70% water, 30% 190 proof ethanol, and a 5 mL glacial acetic acid per 1000 mL combined solvent. To get the system to fill a 10 mL volumetric flask in exactly 10.0 minutes, I need to set solvent compression to 10.5. Is this reasonable. I am using used equipment so I don't have all the manuals and memory from using Waters equipment decades ago.

Thank you,

John