@jack wp - i cleaned the code above. just PH and TMP sensor.
@xl97 now i have just 2 sensors. Both of 2 sensors can be work with 5v. I don't know too much about caps

Just put them there.
@alnath yes, as you can see the code from previous page, there is not any analog readings. I am using serial 1 and serial 2 ports.
38400 bauds is the rate of factory. All sensors came with this settings. I can't change the speed without using delay.
The Story:
First, i am wiring the PH sensor.
Results are good, 6.8 to 6.9 and so on..
I checked this result with the PH sheets. And i tried with low PH waters also like 1.0 to 2.0 etc.
Then when i wire the GND pin of the TMP sensor, PH value sticks to 7.0.
I am continuing to wire other cables and TMP results are accurate even if the PH is always 7.0.
Then i unwire the TMP sensor, i get "check probe" message repeatedly.
I am resetting the Arduino, uploading the code and unplug the usb for "several times" and i am getting the accurate readings again.
I think its weird

Thank you