I kegged my first beer today and had some questions. I set the regulator to 10 psi and pulled the relief valve 3-4 times to push out the oxygen. Then I put the keg and tank into the fridge and set it to 20psi. I check the pressure a few minutes later and it was at 22psi. So i turned it back down to 20psi. I just checked it again and it dropped to 18psi. Why is the co2 fluctuating? Is it because the temperature is dropping in the keg?