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

void loop() {
  // put your main code here, to run repeatedly:

for(int i=0; i<1024; i++)
{
  int tank_level = i;
  Serial.println(tank_level);
  delay(35);
}

delay(1500);

for(int j=1023; j>0; j--)
{
  int tank_level = j;
  Serial.println(tank_level);
  delay(35);
}

}