LED stays on even when digitalRead is low - arduino

Question

I am just creating a simple basic program, but I can't figure out what's going wrong.
I have set three pins as output and three pins as input. When those three pins digitalRead == HIGH they will set an LED to HIGH, but instead my LED is always staying high.
Here is my Arduino code:
int LED_Low = 4; // Red LED
int LED_Avg = 3; // Yellow LED
int LED_High = 2; // Green Led
int WaterLow = 7;
int WaterAvg = 8;
int WaterHigh = 9;
void setup() {
// Put your setup code here, to run once:
pinMode(LED_Low, OUTPUT);
pinMode(LED_Avg, OUTPUT);
pinMode(LED_High, OUTPUT);
pinMode(WaterLow, INPUT);
pinMode(WaterAvg, INPUT);
pinMode(WaterHigh, INPUT);
}
void check(){
if(digitalRead(WaterLow) == HIGH){ // If Water level is low
digitalWrite(ledLow, HIGH); // Turn on red LED indication water level is low
}
else{
digitalWrite(ledLow, LOW);
}
if(digitalRead(WaterAvg) == HIGH){ // If water level is medium
digitalWrite(ledAvg, HIGH); // Turn on yellow LED indicating water level is average
}
else{
digitalWrite(ledAvg, LOW);
}
if(digitalRead(WaterHigh) == HIGH){ //
digitalWrite(ledHigh, HIGH); //
}
else{
digitalWrite(ledHigh, LOW);
}
}
void loop() {
// Put your main code here, to run repeatedly:
check();
}
In the above image I have connected led on pin 2, 3, and 4 with 1.5 kilohm resistor and three wires in pin 7, 8, and 9 which will receive input from the 5 volt pin and turn on the LED. Accordingly, the 5 volt pin is connected to the positive terminal on the power bus and with 9.1 *2 resistors in series and then this wire connect with pin 2, 3, and 4.

Answer 1

I found the issue. My code was OK. It was my circuit.
The pins I declared to receive input were not connected to ground.

Answer 2

You can make that with the help of two cases
Define the delay
if (digitalRead(WaterLow) == HIGH) // If Water level is low
{
digitalWrite(ledLow, HIGH); // Turn red LED indication water level is low
delay(2000);
}
else
{
digitalWrite(ledLow, LOW);
}
Make a condition like this
int stateled = LOW;
int previous = LOW;
long time = 0;
long debounce = 200;
void loop()
{
stateButton = digitalRead(WaterLow);
if (stateButton == HIGH && previous == LOW && millis() - time > debounce)
{
if(stateLED == HIGH)
{
stateLED = LOW;
}
else
{
stateLED = HIGH;
}
time = millis();
}
digitalWrite(ledlow, stateLED);
previous == stateButton;
}