Is there any difference between these two?
https://www.atlas-scientific.com/_files/instructions/Wiringdiagram.pdf
I tried using atlas sample code to the analog pH meter and it won't work. Is there something I need to configure?
Btw, I'm new here so I don't know much of these stuffs. 
They are not the same.
I think that dfrobot.com develops things on their own, they have more thinks that only they sell.
I looked at the sample programs of each pH sensors and find atlas easier to understand. I just started programming and only knows the basics. I want to make a float out of data gathered of the sensor.. something if ph < 5.5, do this, if ph >6.5, do that, just like in atlas.. Anyone can help me? Any advice would be appreciated.
Which Arduino board do you have ?
Did you connect the 5V and GND to the module ? and the analog signal to an analog input pin ?
Did you see the example code at dfrobot ? Did it work ?
The variable 'phValue' in that example is the actual PH value.
So you can do things like this:
if (phValue < 5.5 )
{
 // sound the alarm
}
if (phValue > 6.5 )
{
 // open the valve
}