Index: firmware/App/Controllers/ROPump.c
===================================================================
diff -u -r73fb20333b1987ed00456d32f41ecbf06b0d1b9e -r617a2fa278e4a4426bfbe22b39ae9defbcedd778
--- firmware/App/Controllers/ROPump.c	(.../ROPump.c)	(revision 73fb20333b1987ed00456d32f41ecbf06b0d1b9e)
+++ firmware/App/Controllers/ROPump.c	(.../ROPump.c)	(revision 617a2fa278e4a4426bfbe22b39ae9defbcedd778)
@@ -14,6 +14,7 @@
 * @date    (original)  12-Nov-2024
 *
 ***************************************************************************/
+#include <math.h>           // for log()
 
 #include "Flow.h"
 //#include "NVDataMgmt.h"
@@ -44,17 +45,17 @@
 #define ROP_PRESSURE_CONTROL_P_COEFFICIENT          0.15F                                                               ///< P term for RO pump pressure control.
 #define ROP_PRESSURE_CONTROL_I_COEFFICIENT          0.65F                                                               ///< I term for RO pump pressure control.
 
-#define ROP_FLOW_TO_PWM_SLOPE                       0.2427F                                                              ///< Slope of flow to PWM line equation.
-#define ROP_FLOW_TO_PWM_INTERCEPT                   146.23F                                                                ///< Intercept of flow to PWM line equation.
+#define ROP_FLOW_TO_PWM_SLOPE                       155.31F                                                              ///< Slope of flow to PWM line equation.
+#define ROP_FLOW_TO_PWM_INTERCEPT                   -699.99F                                                                ///< Intercept of flow to PWM line equation.
 #define ROP_PRESSURE_TO_PWM_SLOPE                   0.5F                                                               ///< Slope of pressure to PWM line equation.
 #define ROP_PRESSURE_TO_PWM_INTERCEPT               0.0F                                                                ///< Intercept of pressure  to PWM line equation.
 
 #define DATA_PUBLISH_COUNTER_START_COUNT            10                                                                  ///< Data publish counter start count.
 
-#define ROP_FLOW_TO_PWM_PCT(flow)               ( ( ROP_FLOW_TO_PWM_SLOPE * flow + ROP_FLOW_TO_PWM_INTERCEPT ) / MAX_FLUID_PUMP_PWM_DUTY_CYCLE )         ///< PWM line equation for flow converted to percentage.
-#define ROP_PRESSURE_TO_PWM_PCT(pres)           ( ( ROP_PRESSURE_TO_PWM_SLOPE * pres + ROP_PRESSURE_TO_PWM_INTERCEPT ) / MAX_FLUID_PUMP_PWM_DUTY_CYCLE ) ///< PWM line equation for pressure. converted to percentage
+#define ROP_PRESSURE_TO_PWM_PCT(pres)           ( ( ROP_PRESSURE_TO_PWM_SLOPE * pres + ROP_PRESSURE_TO_PWM_INTERCEPT ) / MAX_FLUID_PUMP_PWM_DUTY_CYCLE ) ///< PWM line equation for pressure. converted to percentage.
 
-#define ROP_FLOW_TO_PWM(flow)                   ( ROP_FLOW_TO_PWM_SLOPE * flow + ROP_FLOW_TO_PWM_INTERCEPT )          ///< PWM line equation for flow converted to percentage.
+#define ROP_FLOW_TO_PWM_PCT(flow)               ( ( ROP_FLOW_TO_PWM_SLOPE * log(flow) + ROP_FLOW_TO_PWM_INTERCEPT ) / MAX_FLUID_PUMP_PWM_DUTY_CYCLE )         ///< PWM line equation for flow converted to percentage.
+#define ROP_FLOW_TO_PWM(flow)                   ( ROP_FLOW_TO_PWM_SLOPE * log(flow) + ROP_FLOW_TO_PWM_INTERCEPT )          ///< PWM line equation for flow converted to percentage.
 
 
 // ********** private data **********
@@ -298,7 +299,7 @@
         if( ( TRUE == roPumpStartControl ) || ( getFilteredFlow( P16_FLOW ) >= ( (F32)getTargetROPumpFlowRateMLPM() * ROP_MIN_FLOW_TO_CONTROL_PCT ) ) )
         {
             nexttgtflow = runPIController( PI_CONTROLLER_ID_RO_PUMP_FLOW, (F32)getTargetROPumpFlowRateMLPM(), getFilteredFlow( P16_FLOW ) );
-            nexttgtflow = MIN( ROP_FLOW_TO_PWM(nexttgtflow), ( MAX_FLUID_PUMP_PWM_DUTY_CYCLE* MAX_FLUID_PUMP_DUTY_CYCLE_PCT ) );
+            nexttgtflow = (U16)MIN( ROP_FLOW_TO_PWM(nexttgtflow), ( MAX_FLUID_PUMP_PWM_DUTY_CYCLE* MAX_FLUID_PUMP_DUTY_CYCLE_PCT ) );
             setFluidPumpPWMDutyCycle( P12_PUMP, nexttgtflow );
             if ( FALSE == roPumpStartControl )
             {