The Tools menu has an Auto Format option that you would be well advised to learn how to use. Often, that is.
You really should think about getting the logic write for one sensor. Right now, you write to one pin when the range is 0 to 50, and to another pin when the range is 50 to 100. You never turn off the other pin. You should be turning off pin 5 when the range is greater than 50, and should be turning off pin 6 when the range is less than 50.
I don't see the point of having 4 sensors that define what happens to one pin.