analogread as trigger not working

hi. I'm pretty new to arduino and need your help troubleshooting my code.
my prodject is an bottle filler. I want to fill diffrent size bottle without telling the arduino which size it's filling. my idea was to use a copperwire and the fillingtube (stainless) and when the water level hits the copper wire circuit is cloesd and use that ass the trigger to close the valve. i made a prototyp on my breadbord and used a potentiometer instead of the copper wire. in my code i want the arduino to read from analog pin and when the volts gets over 4V it should close the valve. hope you guys can help me.

int LEDPin1 = 10;
int buttonPin = 3;
int LEDPin2 = 11;
int LEDPin3 = 12;
int LEDPin4 = 8;
int buttonRead;
int buttonPin3 = 2;
int buttonRead3;
int offPin1 = A0;
int offPin2 = A2;
int readVal;
float V2 = 0;
int dt = 250;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(LEDPin1, OUTPUT);
  pinMode(LEDPin2, OUTPUT);
  pinMode(LEDPin3, OUTPUT);
  pinMode (buttonPin, INPUT);
  pinMode (LEDPin4, OUTPUT);
  pinMode (buttonPin3, INPUT);
  pinMode (offPin1, INPUT);
  pinMode (offPin2, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonRead = digitalRead(buttonPin);
  buttonRead3 = digitalRead(buttonPin3);
  readVal = analogRead (offPin1);
  V2 = (5. / 1023.) * readVal;
  Serial.println(V2);
  delay(dt);
  if (buttonRead == 1) {
    digitalWrite (LEDPin1, LOW);
    digitalWrite (LEDPin2, LOW);
    digitalWrite (LEDPin3, LOW);
  }
  if (buttonRead == 0) {

    digitalWrite (LEDPin1, HIGH);
    delay (1000);
    digitalWrite (LEDPin2, LOW);
    digitalWrite (LEDPin3, LOW);
    delay (1000);
    digitalWrite (LEDPin2, HIGH);
    delay (5000);
    digitalWrite (LEDPin2, LOW);
    delay (2000);

    while (V2 < 4.0) {
      digitalWrite (LEDPin3, HIGH);
      readVal = analogRead (offPin1);
    }

    digitalWrite (LEDPin3, LOW);
    delay (3000);
    digitalWrite (LEDPin1, LOW);

  }
  if (buttonRead3 == 0) {
    digitalWrite (LEDPin4, HIGH);
    delay (5000);
  }
  else {
    digitalWrite (LEDPin4, LOW);
  }
}

sketch_sep22a.ino (1.38 KB)

while (V2 < 4.0) {
      digitalWrite (LEDPin3, HIGH);
      readVal = analogRead (offPin1);
    }

what gets you out of that while?

If you're ever wondering why your code is "not working", use serial debug prints to get it to tell you what it is doing.

marhul:
when the water level hits the copper wire circuit is cloesd

you're saying you have two copper wired extending into the bottom and relying the liquid to conduct a current?

have you tested this with the liquids you plan to dispense?