int HLADINA = 0;
byte RELE = 13;
byte CITAC = 0;
byte MAX = 5;

void setup() {
  pinMode (RELE, OUTPUT);
  Serial.begin (9600);
}

void loop() {
  HLADINA = analogRead(A4);
  Serial.print (HLADINA);
  Serial.print ("(");
  Serial.print (CITAC);
  Serial.print (")");

  // sucho, čerpadlo za minutu stop
  if (HLADINA > 500) {
    delay (600);
    digitalWrite(RELE, LOW);
    Serial.print (" = VYPNUTO");
    CITAC = 0;
  }

  // voda je, čerpadlo start
  if (CITAC >= MAX) {
    delay (500);
    digitalWrite(RELE, HIGH);
    Serial.print (" = ZAPNUTO");
  }

  // nastaveni citace
  if (HLADINA < 500) if (CITAC < MAX) CITAC++;

  Serial.println ();
  delay (1000);
}