int pump10 = 10;
int pump11 = 11;

void setup() {
  pinMode (pump10,OUTPUT);
  pinMode (pump11,OUTPUT);
}

void loop() {
  digitalWrite(pump10,HIGH);
  digitalWrite(pump11,LOW);
  delay(5000);
  digitalWrite(pump10,LOW);
  digitalWrite(pump11,HIGH);
  delay(5000);
}