int trigpin=11;
int echopin=10;
int ledg=2;
int ledr=3;
long duration;
int distance;
void setup() {
  pinMode(trigpin, OUTPUT);
  pinMode(echopin, INPUT);
  pinMode(ledg, OUTPUT);
  pinMode(ledr, OUTPUT);
  Serial.begin(9600);
  // put your setup code here, to run once:

}

void loop() {
  digitalWrite(trigpin, LOW);
  delay(5);
  digitalWrite(trigpin, HIGH);
  delay(10);
  digitalWrite(trigpin, LOW);
  duration=pulseIn(echopin,HIGH);
  distance=duration*0.034/2;
  Serial.println("Distance:");
  Serial.print(distance);
  Serial.println("cm");
  if(distance<20)
  {
    digitalWrite(ledr,HIGH);
    Serial.println("water level is below 20%");
  }
  else if(distance>90)
  {
    digitalWrite(ledg,HIGH);
    Serial.print("Water level is above 90%");
  }
  else
  {
    digitalWrite(ledg,LOW);
    digitalWrite(ledr,LOW);
  }
  // put your main code here, to run repeatedly:

}