 boolean solenoid_valve_open = false;
 double flow_rate_cc_per_min = 0;
 double water_level_buffer; //The water level buffer is how much the water level should increase before calculating a new flow rate
+
+
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////
+//                                           6. SERIAL MONITOR
+unsigned int long PRINT_DELAY = 2000; //in milliseconds
+unsigned int long last_print_time = 0;
+String data; 
+
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////////////// 
 

float casing_temperature = 0.0;
int  idle = 0;
/////////////////////////////////////////////////////////////////////////////////////////////////////////////
//                                                  Tachometer 
const byte TACH = 2;
const byte DURATION = 1;
volatile boolean revolution_occured = false;

 analog_water_level = analogRead(levelSensorPin);
 water_level_cm = ( analog_water_level - B_water_reference_level ) / A_water_rate;

//Set the reference water level for a calculation (when appropriate)
if(initialize==true){
  flow_calc_water_level_cm = water_level_cm;
  calc_time_ms = millis();
