int messwert=0;
int Wasserpumpe = 3;

void setup() {
  // put your setup code here, to run once:
pinMode(Wasserpumpe,OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
messwert=analogRead(A0);
  Serial.print("Feuchtigkeits-Messwert:");
  Serial.println(messwert);
  delay(500);

  if (messwert >700){
    digitalWrite (Wasserpumpe, HIGH);
    delay(7000);
  } else {
    digitalWrite (Wasserpumpe, LOW);
  }

}