What is the flow rate of the water through the filter in gallons per minute? June 10, 2020 17:18 Updated Great question...this will all depend upon your water pressure, but it was tested at 1.25 gallons per minute. Related articles Smart Shield Testing & Certifications Are Epic Filters NSF/ANSI certified? Why have you not tested for this contaminant? Trouble shooting for low flow or leaks. Water is passing through my filter really quickly, is that normal?