Hello there I have a 32 gallon biocube and having problems with ph my dkh is 8.3 cal is 450 and mag is 1450. I run my lights for 11 hrs a day and my tank is mostly sps dominant. During the day my tank gets as high as 7.7 and at night when lights are off it gets as low as 7.20. I've tried water changes, I've tried opening windows in the winter, and even changed out filter media and also calibrated the ph probe multiple times. I do run a small aquaticlife protein skimmer just not having any luck on getting it passed 7.8 for the last month. Thanks for any help and input please