I have a 17ga nano reef tank. All chemistry seems to be fine with the exception of ph which is hanging at 7.8. My buffer puts the water at 8.4 but once in the tank, it drops. I have a skimmer and air stone in the tank so it's probably not a co2 issue. Any suggestions? All inhabitants seem to be doing well but I would like ph at 8.2 as that is within recommended parameters.