in fullauto mode run pumps as a last step to really empty the lines as far as possible.

include/Statemachine.h

         fillnwater_kickstart_run,
         fillnwater_plant_run,
 
-        fullauto_fert, // d i a
-        fullauto_plant, // d i a
-        fullauto_stirr_run, // d i a
-        fullauto_fert_run, // d i a
-        fullauto_tank_run, // d i a
-        fullauto_kickstart_run, // d i a
-        fullauto_plant_run, // d i a
-        fullauto_plant_overrun, // d i a
-        fullauto_tank_purge_run, // d i a
-        fullauto_kickstart_purge_run, // d i a
-        fullauto_plant_purge_run, // d i a
-        fullauto_plant_purge_overrun, // d i a
-        fullauto_done, // d i a
+        fullauto_fert,
+        fullauto_plant,
+        fullauto_stirr_run,
+        fullauto_fert_run,
+        fullauto_tank_run,
+        fullauto_kickstart_run,
+        fullauto_plant_run,
+        fullauto_plant_overrun,
+        fullauto_tank_purge_run,
+        fullauto_kickstart_purge_run,
+        fullauto_plant_purge_run,
+        fullauto_plant_purge_overrun,
+        fullauto_plant_purge_over_pump_run,
+        fullauto_done,
 
         automation_mode,
         

include/config.h

 #define OVERRUN_RUNTIME 75
 #define PURGE_FILL_RUNTIME 20
 #define FULLAUTO_MIN_PLANT_COUNT 2
+#define FULLAUTO_END_PUMP_TIME 30
 
 // Sketch version
 #define FIRMWARE_VERSION "0.6"

src/Statemachine.cpp

     stringify(fullauto_kickstart_purge_run),
     stringify(fullauto_plant_purge_run),
     stringify(fullauto_plant_purge_overrun),
+    stringify(fullauto_plant_purge_over_pump_run),
     stringify(fullauto_done),
 
     stringify(automation_mode),
             || (state == fullauto_plant_run)
             || (state == fullauto_plant_overrun)
             || (state == fullauto_plant_purge_run)
-            || (state == fullauto_plant_purge_overrun)) {
+            || (state == fullauto_plant_purge_overrun)
+            || (state == fullauto_plant_purge_over_pump_run)) {
         plants.abort();
         stop_time = millis();
         switch_to(auto_done);
     if ((state == auto_plant_run) || (state == fillnwater_plant_run)
             || (state == fullauto_plant_run) || (state == fullauto_plant_overrun)
             || (state == fullauto_plant_purge_run)
-            || (state == fullauto_plant_purge_overrun)) {
+            || (state == fullauto_plant_purge_overrun)
+            || (state == fullauto_plant_purge_over_pump_run)) {
         unsigned long runtime = millis() - start_time;
         if ((runtime / 1000UL) >= selected_time) {
             if (state == fullauto_plant_run) {
             } else if (state == fullauto_plant_purge_overrun) {
                 plants.abort();
                 stop_time = millis();
+
+                bool need_kickstart = false;
+                for (int i = 0; i < plants.countPlants(); i++) {
+                    if (selected_plants.isSet(i)) {
+                        if (plants.getKickstart()->getPinNumber(i) >= 0) {
+                            need_kickstart = true;
+                        }
+                    }
+                }
+
+                start_time = millis();
+                selected_time = FULLAUTO_END_PUMP_TIME;
+
+                if (need_kickstart) {
+                    for (int i = 0; i < plants.countPlants(); i++) {
+                        if (selected_plants.isSet(i)) {
+                            plants.startPlant(i, true);
+                        }
+                    }
+
+                    switch_to(fullauto_plant_purge_over_pump_run);
+                } else {
+                    switch_to(fullauto_done);
+                }
+            } else if (state == fullauto_plant_purge_over_pump_run) {
+                plants.abort();
+                stop_time = millis();
                 switch_to(fullauto_done);
             } else {
                 plants.abort();
             switch_to(state);
         }
 
-        if ((state == fullauto_plant_overrun) || (state == fullauto_plant_purge_overrun)) {
+        if ((state == fullauto_plant_overrun)
+                || (state == fullauto_plant_purge_overrun)
+                || (state == fullauto_plant_purge_over_pump_run)) {
             // overrun should not exit when sensor returns empty
             return;
         }
                 start_time = millis();
                 selected_time = OVERRUN_RUNTIME;
                 switch_to(fullauto_plant_purge_overrun);
-
             }
         } else if (wl == Plants::invalid) {
             plants.abort();
               b.c_str(),
               "Hit any key to stop!",
               -1);
-    } else if ((s == fullauto_plant_overrun) || (s == fullauto_plant_purge_overrun)) {
+    } else if ((s == fullauto_plant_overrun)
+            || (s == fullauto_plant_purge_overrun)
+            || (s == fullauto_plant_purge_over_pump_run)) {
         unsigned long runtime = millis() - start_time;
         String a = String(F("Time: ")) + String(runtime / 1000UL) + String(F("s / ")) + String(selected_time) + String('s');