Atlas Scientific pH Stamp Issue

Other Hardware Sensors
6 
while(pH.available() > 0)
{
    Serial.print("pH_available: ");
    Serial.println(pH.available());
    inByte = pH.read();
    Serial.println(inByte);
    inByte = pH.read();
    Serial.println(inByte);
    inByte = pH.read();
    Serial.println(inByte);
    inByte = pH.read();
    Serial.println(inByte);
    inByte = pH.read();
    Serial.println(inByte);

Here, you check to see if there is at least one character to read, then you go ahead and read five of them.
The only thing that is allowing this to work is the delay introduced by the intervening "println"s.
I suggest either checking "available" before every "read", or checking to see if "available" = >= the number of characters you expect.